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  • 51. Johnsen, G
    et al.
    Eikrem, W
    Dalloekken, R
    Legrand, Catherine
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Aure, J
    Skjoldal, HR
    Eco-physiology, bio-optics and toxicity of the ichthyotoxic prymnesiophyte Chrysochromulina leadbeateri1999In: Journal of Phycology, ISSN 0022-3646, E-ISSN 1529-8817, Vol. 35, no 6, p. 1465-1476Article in journal (Refereed)
    Abstract [en]

    A toxic phytoplankton bloom, dominated by the prymnesiophyte Chrysochromulina leadbeateri Estep, developed in the Ofotfjord-Tysfjord area (North Norway) in mid-May and ended in late June 1991 in Vestfjorden and the adjacent fjord areas, Chrysochromulina leadbeateri dominated at total cell densities of >2 x 10(6) cells . L-1; at lower total cell densities, C. leadbeateri was accompanied by other Chrysochromulina species, peridinin-containing dinoflagellates, and diatoms, Bio-optical characteristics and pigmentation in laboratory and field strains of C. leadbeateri allowed for the interpretation of the optical signatures within the bloom. The bio-optical data suggested healthy and actively growing cells during the bloom. About 600 metric tons of pen-raised Atlantic salmon were killed by the C. leadbeateri bloom. A laboratory study was conducted to assess the potential impact of finfish on C. leadbeaferi growth. It was found that the polyamine putrescine enhanced cell biomass and hemolytic activity. Given this, a possible scenario for the development of this bloom and the level of toxicity is hypothesized: (1) The nutrient loading in the Ofotfjord area was enhanced during the winter of 1990-1991 due to the overwintering of 1.5 x 10(6) metric tons of herring from a depth of 0-250 m, This may have sustained a large stock of the mixotrophic C. leadbeateri in early spring before light regime (irradiance, spectral irradiance, and day length) made net photosynthesis possible, (2) The release of polyamines during; the decay of dead fish (e.g. putrescine, cadaverine, and histamine) may have acted as cofactors with ichthyotoxins making "hypertoxic complexes" with the polyamines enhancing growth in the mixotrophic C, leadbeateri.

  • 52.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Algae in Småland and the islands: high value products and waste-to-energy conversion solutions2014In: Presented at CementaHeidelberg, Burglengenfeld, Germany, October 2-3, 2014, 2014Conference paper (Other academic)
  • 53.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Algae in Småland and the islands: High value products and waste-to-energy conversion solutions2014Conference paper (Other (popular science, discussion, etc.))
    Download full text (pdf)
    fulltext
  • 54.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Algoland: industry and ecology together2018In: Presented at the 1st Nordic Algae Symposium 2018 (NAS18), Helsinki, Finland, January 31, 2018, 2018Conference paper (Other academic)
  • 55.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Algoland Workshop: business models2018In: Algoland 2030 Workshop, Kalmar, Sweden, April 24, 2018, 2018Conference paper (Other academic)
  • 56.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Think About Our Environment2015Conference paper (Other (popular science, discussion, etc.))
    Download full text (pdf)
    fulltext
  • 57.
    Legrand, Catherine
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Carlsson, P
    Uptake of high molecular weight dextran by the dinoflagellate Alexandrium catenella1998In: Aquatic Microbial Ecology, ISSN 0948-3055, E-ISSN 1616-1564, Vol. 16, no 1, p. 81-86Article in journal (Refereed)
    Abstract [en]

    Carbohydrate macromolecules (dextrans) labeled with fluorescein isothiocyanate (FITC) were taken up by the dinoflagellate Alexandrium catenella at a substrate concentration of 5 mg C l(-1) The FITC-labeled dextrans appeared in what resembled food vacuoles inside the dinoflagellate cells. Between 5 and 50% of the cells contained fluorescent green vacuoles. A. catenella took up dextrans of high molecular weight (2000 kDa) but did not show significant uptake of lower molecular weight (20 kDa) dextrans. The uptake of the 2000 kDa dextran was higher with addition of humic substances to the growth medium and did not seem related to the presence of bacteria. Phagocytosis of fluorescent microspheres (0.36 mu m) by A. catenella was also investigated. Although aggregation of fluorescent microspheres was observed in the sulcal region of the cells, no evidence was found of phagocytosis of bacterial-size prey by A. catenella. These observations show that A. catenella has the capacity to take up high molecular weight organic molecules. perhaps by pinocytosis.

  • 58.
    Legrand, Catherine
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Casotti, Raffaella
    Stazione Zoologica Anton Dohrn, Napoli, Italy.
    Climate-induced changes and Harmful Algal Blooms in the Mediterranean Sea: Perspectives on future scenarios2009In: CIESM workshop monograph series : Phytoplankton responses to Mediterranean environmental changes, Tunis (Tunisia) 7-10 October 2009, ISSN 1726-5886, no 40, p. 63-66Article, review/survey (Refereed)
  • 59.
    Legrand, Catherine
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Fridolfsson, Emil
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bertos-Fortis, Mireia
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Lindehoff, Elin
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Larsson, Per
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Pinhassi, Jarone
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Andersson, Agneta
    Umeå University.
    Interannual variability of phyto-bacterioplankton biomass and production in coastal and offshore waters of the Baltic Sea2015In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 44, no supplement 3, p. S427-S438Article in journal (Refereed)
    Abstract [en]

    The microbial part of the pelagic food web is seldom characterized in models despite its major contribution to biogeochemical cycles. In the Baltic Sea, spatial and temporal high frequency sampling over three years revealed changes in heterotrophic bacteria and phytoplankton coupling (biomass and production) related to hydrographic properties of the ecosystem. Phyto- and bacterioplankton were bottom-up driven in both coastal and offshore areas. Cold winter temperature was essential for phytoplankton to conform to the successional sequence in temperate waters. In terms of annual carbon production, the loss of the spring bloom (diatoms and dinoflagellates) after mild winters tended not to be compensated for by other taxa, not even summer cyanobacteria. These results improve our ability to project Baltic Sea ecosystem response to short- and long-term environmental changes.

  • 60.
    Legrand, Catherine
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    An eutrophication related mechanism explaining the proliferation of toxic algae in the Baltic Sea2001Report (Other academic)
  • 61.
    Legrand, Catherine
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Effect of nutrient ratios on harmful phytoplankton and their toxin production2000Report (Other academic)
  • 62.
    Legrand, Catherine
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Carlsson, Per
    Induced phagotrophy in the photosynthetic dinoflagellate Heterocapsa triquetra1998In: Aquatic Microbial Ecology, ISSN 0948-3055, E-ISSN 1616-1564, Vol. 15, no 1, p. 65-75Article in journal (Refereed)
    Abstract [en]

    Mixotrophy by the photosynthetic dinoflagellate Heterocapsa triquetra was investigated using fluorescently labelled algae (FLA) (size 1, 3, 6 mu m). Experiments were conducted in nitrogen-and phosphorus-replete/depleted medium under light and dark conditions. Incubations ranged from several hours to several days. The dinoflagellate was capable of phagotrophy when exposed to light and dark periods in nutrient-depleted medium. H. triquetra showed similar ingestion rates in the light (range: 0.1 to 0.4 FLA dino(-1) d(-1)) and in the dark (range: 0.06 to 0.4 FLA dino(-1) d(-1)). The dinoflagellate was able to selectively ingest the different FLA. The cyanobacterium Synechococcus sp, was not ingested, whereas a small round flagellate and the diatom Thalassiosira pseudonana were observed inside the cells. The flagellate was ingested at higher rates than the diatom in both the light and the dark. About 40% of the labelled flagellate was removed from the suspension by H. triquetra in the light and 22% in the dark. The diatom was removed from the suspension at the same rate (27 to 30%) in both light and dark treatments. After 5 d incubation in nutrient-depleted medium and no addition of FLA, the proportion of small H. triquetra cells (<1000 mu m(3)) increased from 50 to over 75%. In the presence of FLA, the distribution of H. triquetra cell volumes showed that the proportion of larger cells (>2000 mu m(3)) increased from 6 to >20% during long incubations in the light and the dark. Since the frequency of observed cells with ingested FLA varied from 3 to 20% for the same period, the proportion of larger cells may be the phagotrophic proportion of the population. However, only 8 (dark) to 12% (light) of the observed H. triquetra cell volume increase can be explained in terms of carbon from the ingestion of fluorescently labelled phytoplankton. We conclude that phagotrophy in H. triquetra may be important in maintaining the population in environments of low nutrient concentration and low light intensity.

  • 63.
    Legrand, Catherine
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Hussenot, J
    Rincé, Y
    Joassard, L
    Mornet, F
    Pirastru, L
    Mass production of microalgae in salt ponds (L Houmeau, France) with farm fertilizer di-ammonium phosphate in addition with silicon1991In: EAS Special Publication 14, 1991, p. 187-188Conference paper (Refereed)
  • 64.
    Legrand, Catherine
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Johansson, N
    Johnsen, G
    Borsheim, K Y
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Phagotrophy and toxicity variation in the mixotrophic Prymnesium patelliferum (Haptophyceae)2001In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 46, no 5, p. 1208-1214Article in journal (Refereed)
    Abstract [en]

    Phagotrophy was investigated in the photosynthetic and ichthyotoxic Prymnesium patelliferum (Haptophyceae) using fluorescent microspheres, fluorescently labeled bacteria, and live bacteria cells. Ingestion rates were estimated both from prey uptake and disappearance experiments in phosphorus (P)-limited and -replete algal cultures. Prymnesium patelliferum was feeding preferentially on bacteria (bact) compared to fluorescent microspheres (FM). Large fluorescent microspheres (1.6 and 3 mum) were ingested at very low rates (< 0.1 FM alga(-1) h(-1)), and small microspheres (0.5 mum) were not ingested. Ingestion of bacteria (mean size 2 mum) was highest in P-limited P. patelliferum cultures (up to four bact alga(-1) h(-1)) compared to P-replete cultures (0-1.2 bact alga(-1) h(-1)). In addition, cellular P content of P-limited cells fed with bacteria became similar to those of P-replete cultures after 48 h, indicating a close relation between cellular P content and feeding behavior. Hemolytic activity of P. patelliferum was up to four times higher in P-limited cultures compared to P-replete cultures. During the transition from P-limiting to P-replete conditions, the addition of bacteria and/or the corresponding bacterial filtrate (< 0.2 mum) and/or PO43- to P-limited cultures resulted in a decrease (50%) of the hemolytic activity after 24 h in relation to controls (no addition of bacteria, filtrate. or P). No PO43- was detectable as a result of enriching cultures with bacterial cells or bacterial filtrates. These results indicate that P. patelliferum can use different sources of P (inorganic and dissolved, organic and particulate) and adapt its mode of nutrition in a short time. Furthermore, the decrease of hemolytic activity in the highly toxic P-limited cells also occurred rapidly following a recovery in cellular P status through mixotrophic feeding or uptake of inorganic phosphate, suggesting that toxicity in P. patelliferum cells can be minimized by nutrient manipulation.

  • 65.
    Legrand, Catherine
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Johnsen, G
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Sakshaug, E
    Effect of polyamines on growth and toxicity of Chrysochromulina leadbeateri (Haptophyte)2001In: Intergov Oceanographic Commission of UNESCO, Paris 2001 / [ed] Hallegraeff GM, Blackburn SI, Bolch CJ, Lewis RJ, 2001Conference paper (Refereed)
  • 66.
    Legrand, Catherine
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Lindehoff, Elin
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Olofsson, Martin
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Mikroalgers potential inom biofiltering av industriell rökgas och processvatten2014Conference paper (Other (popular science, discussion, etc.))
  • 67.
    Legrand, Catherine
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Malinsky-Rushansky, NZ
    Organic production and excretion by different phytoplankton size classes1993In: WI Li & Sy Maestrini (eds) ICES Marine Science Symposia Measurements of primary production from the molar to the global scale, 1993Conference paper (Refereed)
  • 68.
    Legrand, Catherine
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olofsson, Martin
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Growing algae in Scandinavia: utopia or opportunity?2011In: Algae: The sustainable biomass for the future.: Perspectives from the submariner project algae cooperation event Trelleborg, Sweden - September 28-29, 2011., Berlin, Germany: s.Pro sustainable projects GmbH , 2011, p. 16-17Conference paper (Other (popular science, discussion, etc.))
  • 69.
    Legrand, Catherine
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Rengefors, Karin
    Fistarol, Giovana
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Allelopathy in phytoplankton – biochemical, ecological and evolutionary aspects2003In: Phycologia, ISSN 0031-8884, E-ISSN 2330-2968, Vol. 42, no 4, p. 406-419Article in journal (Refereed)
    Abstract [en]

    It is considered self-evident that chemical interactions are a component of competition in terrestrial systems, but they are largely unknown in aquatic systems. In this review, we propose that chemical interactions, specifically allelopathy, are an important part of phytoplankton competition. Allelopathy, as defined here, applies only to the inhibitory effects of secondary metabolites produced by one species on the growth or physiological function of another phytoplankton species. A number of approaches are used to study allelopathy, but there is no standard methodology available. One of the methods used is cross-culturing, in which the cell-free filtrate of a donor alga is added to the medium of the target species. Another is to study the effect of cell extracts of unknown constituents, isolated exudates or purified allelochemicals on the growth of other algal species. There is a clear lack of controlled field experiments because few allelochemicals have been identified. Molecular methods will be important in future to study the expression and regulation of allelochemicals. Most of the identified allelochemicals have been described for cyanobacteria but some known toxins of marine dinoflagellates and freshwater cyanobacteria also have an allelochemical effect. The mode of action of allelochemicals spans a wide range. The most common effect is to cause cell lysis, blistering, or growth inhibition. The factors that affect allelochemical production have not been studied much, although nutrient limitation, pH, and temperature appear to have an effect. The evolutionary aspects of allelopathy remain largely unknown, but we hypothesize that the producers of allelochemicals should gain a competitive advantage over other phytoplankton. Finally, we discuss the possibility of using allelochemicals to combat harmful algal blooms (HABs). Allelopathic agents are used for biological control in agriculture, e.g. green manures to control soil diseases in Australia, but they have not yet been applied in the context of HABs. We suggest that phytoplankton allelochemicals have the potential for management of HABs in localized areas.

  • 70.
    Legrand, Catherine
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Sæmundsdottir, S
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Phagotrophy in Chrysochromulina polylepis (Prymnesiophyceae): ingestion of Fluorescent Labelled Algae (FLA) under different nutrient conditions1996In: Intergovernmental Oceanographic Commission of UNESCO In: Yasumoto T, Oshima Y, Fukuyo Y (eds) Harmful and Toxic Algal Blooms, Paris, 1996Conference paper (Refereed)
  • 71.
    Lindehoff, Elin
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Finnish Environm Inst, Finland.
    Jerney, J.
    Finnish Environm Inst, Finland.
    Le Tortorec, A.
    Finnish Environm Inst, Finland.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Savela, H.
    Univ Turku, Finland.
    Svahn, E.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Suikkanen, S.
    Finnish Environm Inst, Finland.
    Kremp, A.
    Finnish Environm Inst, Finland.
    Nitrogen Supply Mechanisms in Toxic Dinoflagellate Alexandrium ostenfeldii - the Key to Bloom Expansion in Coastal Baltic Waters?2017In: Phycologia, ISSN 0031-8884, E-ISSN 2330-2968, Vol. 56, no 4, p. 118-119Article in journal (Other academic)
  • 72.
    Lindehoff, Elin
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Briggen Tre Kronor: Algoland2014Conference paper (Other (popular science, discussion, etc.))
  • 73.
    Lindh, Markus V.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Figueroa, Daniela
    Umeå University.
    Sjöstedt, Johanna
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Baltar, Federico
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. University of Otago, New Zealand.
    Lundin, Daniel
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Andersson, Agneta
    Umeå University.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Pinhassi, Jarone
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Transplant experiments uncover Baltic Sea basin-specific responses in bacterioplankton community composition and metabolic activities2015In: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 6, article id 223Article in journal (Refereed)
    Abstract [en]

    Anthropogenically induced changes in precipitation are projected to generate increased river runoff to semi-enclosed seas, increasing loads of terrestrial dissolved organic matter and decreasing salinity. To determine how bacterial community structure and functioning adjust to such changes, we designed microcosm transplant experiments with Baltic Proper (salinity 7.2) and Bothnian Sea (salinity 3.6) water. Baltic Proper bacteria generally reached higher abundances than Bothnian Sea bacteria in both Baltic Proper and Bothnian Sea water, indicating higher adaptability. Moreover, Baltic Proper bacteria growing in Bothnian Sea water consistently showed highest bacterial production and beta-glucosidase activity. These metabolic responses were accompanied by basin-specific changes in bacterial community structure. For example, Baltic Proper Pseudomonas and Limnobacter populations increased markedly in relative abundance in Bothnian Sea water, indicating a replacement effect. In contrast, Roseobacter and Rheinheimera populations were stable or increased in abundance when challenged by either of the waters, indicating an adjustment effect. Transplants to Bothnian Sea water triggered the initial emergence of particular Burkholderiaceae populations, and transplants to Baltic Proper water triggered Alteromonadaceae populations. Notably, in the subsequent re-transplant experiment, a priming effect resulted in further increases to dominance of these populations. Correlated changes in community composition and metabolic activity were observed only in the transplant experiment and only at relatively high phylogenetic resolution. This suggested an importance of successional progression for interpreting relationships between bacterial community composition and functioning. We infer that priming effects on bacterial community structure by natural episodic events or climate change induced forcing could translate into long-term changes in bacterial ecosystem process rates.

  • 74.
    Lindh, Markus V.
    et al.
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Sjöstedt, Johanna
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Andersson, Anders F.
    KTH Royal Inst Technol, Sweden.
    Baltar, Federico
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Hugerth, Luisa
    KTH Royal Inst Technol, Sweden.
    Lundin, Daniel
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Muthusamy, Sarala Devi
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Legrand, Catherine
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Pinhassi, Jarone
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Disentangling seasonal bacterioplankton population dynamics by high-frequency sampling2015In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 17, no 7, p. 2459-2476Article in journal (Refereed)
    Abstract [en]

    Multiyear comparisons of bacterioplankton succession reveal that environmental conditions drive community shifts with repeatable patterns between years. However, corresponding insight into bacterioplankton dynamics at a temporal resolution relevant for detailed examination of variation and characteristics of specific populations within years is essentially lacking. During 1 year, we collected 46 samples in the Baltic Sea for assessing bacterial community composition by 16S rRNA gene pyrosequencing (nearly twice weekly during productive season). Beta-diversity analysis showed distinct clustering of samples, attributable to seemingly synchronous temporal transitions among populations (populations defined by 97% 16S rRNA gene sequence identity). A wide spectrum of bacterioplankton dynamics was evident, where divergent temporal patterns resulted both from pronounced differences in relative abundance and presence/absence of populations. Rates of change in relative abundance calculated for individual populations ranged from 0.23 to 1.79 day(-1). Populations that were persistently dominant, transiently abundant or generally rare were found in several major bacterial groups, implying evolution has favoured a similar variety of life strategies within these groups. These findings suggest that high temporal resolution sampling allows constraining the timescales and frequencies at which distinct populations transition between being abundant or rare, thus potentially providing clues about physical, chemical or biological forcing on bacterioplankton community structure.

  • 75.
    Lindh, Markus V.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Sjöstedt, Johanna
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Andersson, Anders F.
    KTH Royal Inst Technol.
    Baltar, Federico
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Univ Otago, New Zealand.
    Hugerth, Luisa
    KTH Royal Inst Technol.
    Lundin, Daniel
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Muthusamy, Sarala Devi
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Pinhassi, Jarone
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Disentangling seasonal bacterioplankton population dynamics by high-frequency sampling2015In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 17, no 7, p. 2459-2476Article in journal (Refereed)
    Abstract [en]

    Multiyear comparisons of bacterioplankton succession reveal that environmental conditions drive community shifts with repeatable patterns between years. However, corresponding insight into bacterioplankton dynamics at a temporal resolution relevant for detailed examination of variation and characteristics of specific populations within years is essentially lacking. During 1 year, we collected 46 samples in the Baltic Sea for assessing bacterial community composition by 16S rRNA gene pyrosequencing (nearly twice weekly during productive season). Beta-diversity analysis showed distinct clustering of samples, attributable to seemingly synchronous temporal transitions among populations (populations defined by 97% 16S rRNA gene sequence identity). A wide spectrum of bacterioplankton dynamics was evident, where divergent temporal patterns resulted both from pronounced differences in relative abundance and presence/absence of populations. Rates of change in relative abundance calculated for individual populations ranged from 0.23 to 1.79 day(-1). Populations that were persistently dominant, transiently abundant or generally rare were found in several major bacterial groups, implying evolution has favoured a similar variety of life strategies within these groups. These findings suggest that high temporal resolution sampling allows constraining the timescales and frequencies at which distinct populations transition between being abundant or rare, thus potentially providing clues about physical, chemical or biological forcing on bacterioplankton community structure.

  • 76.
    Lindh, Markus V.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Lund University.
    Sjöstedt, Johanna
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Lund University;Tech Univ Denmark, Denmark.
    Casini, Michele
    Swedish University of Agricultural Sciences.
    Andersson, Agneta
    Umeå University.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Pinhassi, Jarone
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Local Environmental Conditions Shape Generalist But Not Specialist Components of Microbial Metacommunities in the Baltic Sea2016In: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 7, p. 1-10, article id 2078Article in journal (Refereed)
    Abstract [en]

    Marine microbes exhibit biogeographical patterns linked with fluxes of matter and energy. Yet, knowledge of the mechanisms shaping bacterioplankton community assembly across temporal scales remains poor. We examined bacterioplankton 16S rRNA gene fragments obtained from Baltic Sea transects to determine phylogenetic relatedness and assembly processes coupled with niche breadth. Communities were phylogenetically more related over time than expected by chance, albeit with considerable temporal variation. Hence, habitat filtering, i.e., local environmental conditions, rather than competition structured bacterioplankton communities in summer but not in spring or autumn. Species sorting (SS) was the dominant assembly process, but temporal and taxonomical variation in mechanisms was observed. For May communities, Cyanobacteria, Actinobacteria, Alpha- and Betaproteobacteria exhibited SS while Bacteroidetes and Verrucomicrobia were assembled by SS and mass effect. Concomitantly, Gammaproteobacteria were assembled by the neutral model and patch dynamics. Temporal variation in habitat filtering and dispersal highlights the impact of seasonally driven reorganization of microbial communities. Typically abundant Baltic Sea populations such as the NS3a marine group (Bacteroidetes) and the SAR86 and SAR11 clade had the highest niche breadth. The verrucomicrobial Spartobacteria population also exhibited high niche breadth. Surprisingly, variation in bacterioplankton community composition was regulated by environmental factors for generalist taxa but not specialists. Our results suggest that generalists such as NS3a, SAR86, and SAR11 are reorganized to a greater extent by changes in the environment compared to specialists and contribute more strongly to determining overall biogeographical patterns of marine bacterial communities.

  • 77.
    Lindh, Markus V.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Lund University.
    Sjöstedt, Johanna
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Lund University ; Technical University of Denmark, Denmark.
    Ekstam, Börje
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Casini, Michele
    Swedish University of Agricultural Sciences.
    Lundin, Daniel
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Hugerth, Luisa
    KTH Royal Institute of Technology.
    Hu, Yue
    KTH Royal Institute of Technology.
    Andersson, Anders
    KTH Royal Institute of Technology.
    Andersson, Agneta
    Umeå University.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Pinhassi, Jarone
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Metapopulation theory identifies biogeographical patterns among core and satellite marine bacteria scaling from tens to thousands of kilometers2017In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 19, no 3, p. 1222-1236Article in journal (Refereed)
    Abstract [en]

    Metapopulation theory developed in terrestrial ecology provides applicable frameworks for interpreting the role of local and regional processes in shaping species distribution patterns. Yet, empirical testing of metapopulation models on microbial communities is essentially lacking. We determined regional bacterioplankton dynamics from monthly transect sampling in the Baltic Sea Proper using 16S rRNA gene sequencing. A strong positive trend was found between local relative abundance and occupancy of populations. Notably, the occupancy-frequency distributions were significantly bimodal with a satellite mode of rare endemic populations and a core mode of abundant cosmopolitan populations (e.g. Synechococcus, SAR11 and SAR86 clade members). Temporal changes in population distributions supported several theoretical frameworks. Still, bimodality was found among bacterioplankton communities across the entire Baltic Sea, and was also frequent in globally distributed datasets. Datasets spanning waters with widely different physicochemical characteristics or environmental gradients typically lacked significant bimodal patterns. When such datasets were divided into subsets with coherent environmental conditions, bimodal patterns emerged, highlighting the importance of positive feedbacks between local abundance and occupancy within specific biomes. Thus, metapopulation theory applied to microbial biogeography can provide novel insights into the mechanisms governing shifts in biodiversity resulting from natural or anthropogenically induced changes in the environment.

  • 78.
    Majaneva, Sanna
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. UiT The Arctic University of Norway, Norway;Norwegian University of Science and Technology, Norway.
    Fridolfsson, Emil
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Casini, Michele
    Swedish University of Agricultural Sciences, Sweden.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Lindehoff, Elin
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Margonski, Piotr
    National Marine Fisheries Research Institute, Poland.
    Majaneva, Markus
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science. Norwegian University of Science and Technology, Norway.
    Nilsson, Jonas
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Rubene, Gunta
    Institute of Food Safety, Animal Health and Environment BIOR, Latvia .
    Wasmund, Norbert
    Leibniz-Institute for Baltic Sea Research, Germany.
    Hylander, Samuel
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Deficiency syndromes in top predators associated with large-scale changes in the Baltic Sea ecosystem2020In: PLoS ONE, E-ISSN 1932-6203, Vol. 15, no 1, article id e0227714Article in journal (Refereed)
    Abstract [en]

    Vitamin B1 (thiamin) deficiency is an issue periodically affecting a wide range of taxa worldwide. In aquatic pelagic systems, thiamin is mainly produced by bacteria and phytoplankton and is transferred to fish and birds via zooplankton, but there is no general consensus on when or why this transfer is disrupted. We focus on the occurrence in salmon (Salmo salar) of a thiamin deficiency syndrome (M74), the incidence of which is highly correlated among populations derived from different spawning rivers. Here, we show that M74 in salmon is associated with certain large-scale abiotic changes in the main common feeding area of salmon in the southern Baltic Sea. Years with high M74 incidence were characterized by stagnant periods with relatively low salinity and phosphate and silicate concentrations but high total nitrogen. Consequently, there were major changes in phytoplankton and zooplankton, with, e.g., increased abundances of Cryptophyceae, Dinophyceae, Diatomophyceae and Euglenophyceae and Acartia spp. during high M74 incidence years. The prey fish communities also had increased stocks of both herring and sprat in these years. Overall, this suggests important changes in the entire food web structure and nutritional pathways in the common feeding period during high M74 incidence years. Previous research has emphasized the importance of the abundance of planktivorous fish for the occurrence of M74. By using this 27-year time series, we expand this analysis to the entire ecosystem and discuss potential mechanisms inducing thiamin deficiency in salmon.

  • 79. Malinsky-Rushansky, NZ
    et al.
    Legrand, Catherine
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Excretion of dissolved organic carbon by phytoplankton of different size and subsequent bacterial uptake1996In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 132, no 1-3, p. 249-255Article in journal (Refereed)
    Abstract [en]

    Identical techniques and laboratory equipment were used to compare photosynthetic particulate assimilation and excretion of dissolved organic compounds (EOC) by different size classes of phytoplankton from marine and freshwater ecosystems. The subsequent assimilation and respiration of these algal exudates by bacteria were measured. The percentage of extracellular release of dissolved organic compounds was lower (4 to 5 %) for larger algal cells than for picoeukaryotes (29 %). Bacterial assimilation of the EOC released by the algae under these conditions seemed to be related more to algal species than to biovolume, although there may also be an effect on the specific bacterial assemblages. Bacterial uptake and utilization of EOC was 19% for freshwater picoeukaryotes, and 18 to 70 % for marine nanoplankton. Great variations were found in the respiration rates of natural bacteria on EOC released by the freshwater picoalgae (95 %) and nanoplanktonic salt pond algae (20 to 41%).

  • 80.
    Mattsson, Lina
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Lindehoff, Elin
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Olofsson, Martin
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Boosting algal lipids: Diurnal shifts in temperature exceed the effects of nitrogen limitation2019In: Engineering Reports, E-ISSN 2577-8196, Vol. 1, no 5, p. 1-13, article id e12067Article in journal (Refereed)
    Abstract [en]

    Algal lipids have been observed to increase during autumn conditions (low light, low mean temperature, and diurnal shift in temperature), in large‐scale outdoor photobioreactors. In this paper, we tested the effect of diurnal shifts in temperature (DS) and nitrogen (N) limitation on algal BODIPY lipid fluorescence cell−1 (BPF). We show that DS increased BPF in algal biomass up to 28% more compared with N limitation, the standard stressor to boost neutral lipids (NL) in commercial production. Biomass yield was constant, regardless the DS range (6°C‐12°C). A combination of both stressors had an additive effect on algal BPF. A polyculture from an outdoor photobioreactor was cultivated under controlled conditions at different regimes of light, temperature, and N limitation. DSs were mimicking autumn conditions with a difference of 6°C, 10°C, and 12°C between day and night. Biomass and BPF were monitored over one to two weeks, and NLs were stained with a fluorescent marker (BODIPY) and detected with flow cytometry. Results indicate that, during autumn conditions, daily heating and cooling processes in contrast to N limitation do not challenge the trade‐off between biomass production and BPF. During seasons when day temperature is still relatively high, DSs are rapid BPF boosting stressors, while N limitation could be applied to boost BPF further during other seasons.

  • 81.
    Mazur-Marzec, Hanna
    et al.
    University of Gdansk, Poland.
    Bertos-Fortis, Mireia
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Torunska-Sitarz, Anna
    University of Gdansk, Poland.
    Fidor, Anna
    University of Gdansk, Poland.
    Legrand, Catherine
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Chemical and Genetic Diversity of Nodularia spumigena from the Baltic Sea2016In: Marine Drugs, ISSN 1660-3397, E-ISSN 1660-3397, Vol. 14, no 11, article id 209Article in journal (Refereed)
    Abstract [en]

    Nodularia spumigena is a toxic, filamentous cyanobacterium occurring in brackish waters worldwide, yet forms extensive recurrent blooms in the Baltic Sea. N. spumigena produces several classes of non-ribosomal peptides (NRPs) that are active against several key metabolic enzymes. Previously, strains from geographically distant regions showed distinct NRP metabolic profiles. In this work, conspecific diversity in N. spumigena was studied using chemical and genetic approaches. NRP profiles were determined in 25 N. spumigena strains isolated in different years and from different locations in the Baltic Sea using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Genetic diversity was assessed by targeting the phycocyanin intergenic spacer and flanking regions (cpcBA-IGS). Overall, 14 spumigins, 5 aeruginosins, 2 pseudaeruginosins, 2 nodularins, 36 anabaenopeptins, and one new cyanopeptolin-like peptide were identified among the strains. Seven anabaenopeptins were new structures; one cyanopeptolin-like peptide was discovered in N. spumigena for the first time. Based on NRP profiles and cpcBA-IGS sequences, the strains were grouped into two main clusters without apparent influence of year and location, indicating persistent presence of these two subpopulations in the Baltic Sea. This study is a major step in using chemical profiling to explore conspecific diversity with a higher resolution than with a sole genetic approach.

  • 82.
    Mazur-Marzec, Hanna
    et al.
    University of Gdansk, Poland.
    Bertos-Fortis, Mireia
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Torunska-Sitarz, Anna
    University of Gdansk, Poland.
    Fidor, Anna
    University of Gdansk, Poland.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Chemical and Genetic Diversity of Nodularia spumigena from the Baltic Sea2016In: Marine Drugs, ISSN 1660-3397, E-ISSN 1660-3397, Vol. 14, no 11, article id 209Article in journal (Refereed)
    Abstract [en]

    Nodularia spumigena is a toxic, filamentous cyanobacterium occurring in brackish waters worldwide, yet forms extensive recurrent blooms in the Baltic Sea. N. spumigena produces several classes of non-ribosomal peptides (NRPs) that are active against several key metabolic enzymes. Previously, strains from geographically distant regions showed distinct NRP metabolic profiles. In this work, conspecific diversity in N. spumigena was studied using chemical and genetic approaches. NRP profiles were determined in 25 N. spumigena strains isolated in different years and from different locations in the Baltic Sea using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Genetic diversity was assessed by targeting the phycocyanin intergenic spacer and flanking regions (cpcBA-IGS). Overall, 14 spumigins, 5 aeruginosins, 2 pseudaeruginosins, 2 nodularins, 36 anabaenopeptins, and one new cyanopeptolin-like peptide were identified among the strains. Seven anabaenopeptins were new structures; one cyanopeptolin-like peptide was discovered in N. spumigena for the first time. Based on NRP profiles and cpcBA-IGS sequences, the strains were grouped into two main clusters without apparent influence of year and location, indicating persistent presence of these two subpopulations in the Baltic Sea. This study is a major step in using chemical profiling to explore conspecific diversity with a higher resolution than with a sole genetic approach.

  • 83.
    Olofsson, Martin
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Del Pino, Victoria
    NECTON Company, Portugal.
    Lamela, Teresa
    NECTON Company, Portugal.
    Bergé, Jean Pascal
    Ifremer Nantes, France.
    Nilsson, Emmelie
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Legrand, Catherine
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Are algal oil yield estimations dependent on seasonal variation?2011In: Algae: The sustainable biomass for the future. Perspectives from the submariner project algae cooperation event Trelleborg, Sweden - September 28-29, 2011 / [ed] Cecilia Torres, Berlin, Germany: s.Pro-sustainable projects GmbH , 2011, p. 44-45Conference paper (Other (popular science, discussion, etc.))
  • 84.
    Olofsson, Martin
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lamela, Teresa
    Nilsson, Emmelie
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Bergé, Jean Pascal
    del Pino, Victória
    Uronen, Pauliina
    Legrand, Catherine
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Seasonal variation of lipids and fatty acids of the microalgae Nannochloropsis oculata grown in outdoor large-scale photobioreactors2012In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 5, no 5, p. 1577-1592Article in journal (Refereed)
    Abstract [en]

    While focus in oil-producing microalgae is normally on nutrient deficiency, we

    addressed the seasonal variations of lipid content and composition in large-scale

    cultivation. Lipid content, fatty acid profiles and mono- di- and triglycerides (MAGs,

    DAGs, and TAGs) were analyzed during May 2007–May 2009 in Nannochloropsis oculata

    grown outdoors in closed vertical flat panels photobioreactors. Total lipids (TL) ranged

    from 11% of dry weight (DW) in winter to 30% of DW in autumn. 50% of the variation in

    TL could be explained by light and temperature. As the highest lipid content was recorded

    during autumn indicating an optimal, non-linear, response to light and temperature we

    hypothesize that enhanced thylakoid stacking under reduced light conditions resulted in

    more structural lipids, concomitantly with the increase in glycerides due to released

    photo-oxidative stress. The relative amount of monounsaturated fatty acids (MUFA)

    increased during autumn. This suggested a synthesis, either of structural fatty acids as

    MUFA, or a relative increase of C16:1 incorporated into TAGs and DAGs. Our results

    emphasize the significant role of environmental conditions governing lipid content and 

    composition in microalgae that have to be considered for correct estimation of algal oil

    yields in biodiesel production.

  • 85.
    Olofsson, Martin
    et al.
    Linnéuniversitetet, Institutionen för naturvetenskap, NV.
    Lamela, Teresa
    Nilsson, Emmelie
    Linnéuniversitetet, Institutionen för naturvetenskap, NV.
    Bergé, Jean Pascal
    del Pino, Victória
    Uronen, Pauliina
    Legrand, Catherine
    Linnéuniversitetet, Institutionen för naturvetenskap, NV.
    Seasonal variation of lipids and fatty acids of the microalgae Nannochloropsis oculata grown in outdoor large-scale photobioreactors2012In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 5, no 5, p. 1577-1592Article in journal (Refereed)
    Abstract [en]

    While focus in oil-producing microalgae is normally on nutrient deficiency, we

    addressed the seasonal variations of lipid content and composition in large-scale

    cultivation. Lipid content, fatty acid profiles and mono- di- and triglycerides (MAGs,

    DAGs, and TAGs) were analyzed during May 2007–May 2009 in Nannochloropsis oculata

    grown outdoors in closed vertical flat panels photobioreactors. Total lipids (TL) ranged

    from 11% of dry weight (DW) in winter to 30% of DW in autumn. 50% of the variation in

    TL could be explained by light and temperature. As the highest lipid content was recorded

    during autumn indicating an optimal, non-linear, response to light and temperature we

    hypothesize that enhanced thylakoid stacking under reduced light conditions resulted in

    more structural lipids, concomitantly with the increase in glycerides due to released

    photo-oxidative stress. The relative amount of monounsaturated fatty acids (MUFA)

    increased during autumn. This suggested a synthesis, either of structural fatty acids as

    MUFA, or a relative increase of C16:1 incorporated into TAGs and DAGs. Our results

    emphasize the significant role of environmental conditions governing lipid content and 

    composition in microalgae that have to be considered for correct estimation of algal oil

    yields in biodiesel production.

  • 86.
    Olofsson, Martin
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Lamela, Teresa
    Necton SA, Olhao, Portugal.
    Nilsson, Emmelie
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bergé, Jean-Pascal
    IFREMER, Nantes, France.
    del Pino, Victória
    Necton SA, Olhao, Portugal.
    Uronen, Pauliina
    Neste Oil, Ctr Technol, Porvoo, Finland.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Combined Effects of Nitrogen Concentration and Seasonal Changes on the Production of Lipids in Nannochloropsis oculata 2014In: Marine Drugs, ISSN 1660-3397, E-ISSN 1660-3397, Vol. 12, no 4, p. 1891-1910Article in journal (Refereed)
    Abstract [en]

    Instead of sole nutrient starvation to boost algal lipid production, we addressed nutrient limitation at two different seasons (autumn and spring) during outdoor cultivation in flat panel photobioreactors. Lipid accumulation, biomass and lipid productivity and changes in fatty acid composition of Nannochloropsis oculata were investigated under nitrogen (N) limitation (nitrate:phosphate N:P 5, N:P 2.5 molar ratio). N. oculata was able to maintain a high biomass productivity under N-limitation compared to N-sufficiency (N:P 20) at both seasons, which in spring resulted in nearly double lipid productivity under N-limited conditions (0.21 g L−1 day−1) compared to N-sufficiency (0.11 g L−1 day−1). Saturated and monounsaturated fatty acids increased from 76% to nearly 90% of total fatty acids in N-limited cultures. Higher biomass and lipid productivity in spring could, partly, be explained by higher irradiance, partly by greater harvesting rate (~30%). Our results indicate the potential for the production of algal high value products (i.e., polyunsaturated fatty acids) during both N-sufficiency and N-limitation. To meet the sustainability challenges of algal biomass production, we propose a dual-system process: Closed photobioreactors producing biomass for high value products and inoculum for larger raceway ponds recycling waste/exhaust streams to produce bulk chemicals for fuel, feed and industrial material.

  • 87.
    Olofsson, Martin
    et al.
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Lamela, Teresa
    Necton SA, Olhao, Portugal.
    Nilsson, Emmelie
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Bergé, Jean-Pascal
    IFREMER, Nantes, France.
    del Pino, Victória
    Necton SA, Olhao, Portugal.
    Uronen, Pauliina
    Neste Oil, Ctr Technol, Porvoo, Finland.
    Legrand, Catherine
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Combined Effects of Nitrogen Concentration and Seasonal Changes on the Production of Lipids in Nannochloropsis oculata 2014In: Marine Drugs, ISSN 1660-3397, E-ISSN 1660-3397, Vol. 12, no 4, p. 1891-1910Article in journal (Refereed)
    Abstract [en]

    Instead of sole nutrient starvation to boost algal lipid production, we addressed nutrient limitation at two different seasons (autumn and spring) during outdoor cultivation in flat panel photobioreactors. Lipid accumulation, biomass and lipid productivity and changes in fatty acid composition of Nannochloropsis oculata were investigated under nitrogen (N) limitation (nitrate:phosphate N:P 5, N:P 2.5 molar ratio). N. oculata was able to maintain a high biomass productivity under N-limitation compared to N-sufficiency (N:P 20) at both seasons, which in spring resulted in nearly double lipid productivity under N-limited conditions (0.21 g L−1 day−1) compared to N-sufficiency (0.11 g L−1 day−1). Saturated and monounsaturated fatty acids increased from 76% to nearly 90% of total fatty acids in N-limited cultures. Higher biomass and lipid productivity in spring could, partly, be explained by higher irradiance, partly by greater harvesting rate (~30%). Our results indicate the potential for the production of algal high value products (i.e., polyunsaturated fatty acids) during both N-sufficiency and N-limitation. To meet the sustainability challenges of algal biomass production, we propose a dual-system process: Closed photobioreactors producing biomass for high value products and inoculum for larger raceway ponds recycling waste/exhaust streams to produce bulk chemicals for fuel, feed and industrial material.

  • 88.
    Olofsson, Martin
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    ALGOLAND – Recovery: Avfall används för att producera en värdefull produkt - algbiomassa2017In: Linnaeus Technical Centre (LTC) och Linnaeus Innovation Design Lab (Lidlab), May 8th 2017, 2017Conference paper (Other academic)
  • 89.
    Olofsson, Martin
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Lindehoff, Elin
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Frick, Brage
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Svensson, Fredrik
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Baltic Sea microalgae transform cement flue gas into valuable biomass2015In: Algal Research, ISSN 2211-9264, Vol. 11, p. 227-233Article in journal (Refereed)
    Abstract [en]

    We show high feasibility of using cement industrial flue gas as CO2 source for microalgal cultivation. The toxicity of cement flue gas (12-15% CO2) on algal biomass production and composition (lipids, proteins, carbohydrates) was tested using monocultures (Tetraselmis sp., green algae, Skeletonema marinoi, diatom) and natural brackish communities. The performance of a natural microalgal community dominated by spring diatoms was compared to a highly productive diatom monoculture S. marinoi fed with flue gas or air-CO2 mixture. Flue gas was not toxic to any of the microalgae tested. Instead we show high quality of microalgal biomass (lipids 20-30% DW, proteins 20-28% DW, carbohydrates 15-30% DW) and high production when cultivated with flue gas addition compared to CO2-air. Brackish Baltic Sea microalgal communities performed equally or better in terms of biomass quality and production than documented monocultures of diatom and green algae, often used in algal research and development. Hence, we conclude that microalgae should be included in biological solutions to transform waste into renewable resources in coastal waters. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

  • 90.
    Olofsson, Martin
    et al.
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Lindehoff, Elin
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Frick, Brage
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Svensson, Fredrik
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Legrand, Catherine
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Baltic Sea microalgae transform cement flue gas into valuable biomass2015In: Algal Research, ISSN 2211-9264, Vol. 11, p. 227-233Article in journal (Refereed)
    Abstract [en]

    We show high feasibility of using cement industrial flue gas as CO2 source for microalgal cultivation. The toxicity of cement flue gas (12-15% CO2) on algal biomass production and composition (lipids, proteins, carbohydrates) was tested using monocultures (Tetraselmis sp., green algae, Skeletonema marinoi, diatom) and natural brackish communities. The performance of a natural microalgal community dominated by spring diatoms was compared to a highly productive diatom monoculture S. marinoi fed with flue gas or air-CO2 mixture. Flue gas was not toxic to any of the microalgae tested. Instead we show high quality of microalgal biomass (lipids 20-30% DW, proteins 20-28% DW, carbohydrates 15-30% DW) and high production when cultivated with flue gas addition compared to CO2-air. Brackish Baltic Sea microalgal communities performed equally or better in terms of biomass quality and production than documented monocultures of diatom and green algae, often used in algal research and development. Hence, we conclude that microalgae should be included in biological solutions to transform waste into renewable resources in coastal waters. (C) 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

  • 91.
    Olofsson, Martin
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Lindehoff, Elin
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Production stability and biomass quality in microalgal cultivation: contribution of community dynamics2019In: Engineering in Life Sciences, ISSN 1618-0240, E-ISSN 1618-2863, Vol. 19, no 5, p. 330-340Article in journal (Refereed)
    Abstract [en]

    The prospect of using constructed communities of microalgae in algal cultivation wasconfirmed in this study. Three constructed communities of diatoms (Diatom), greenalgae (Green) and cyanobacteria (Cyano), were each mixed with a natural communityof microalgae as baseline. The communities were cultivated in batch and semicontinuousmode and fed CO2 or cement flue gas (12-15 % CO2). Diatom had thehighest growth rate but Green had the highest yield. Dynamic changes in thecommunity composition occurred from start through batch to semi-steady state. Greenalgae were the most competitive group during the experiment. Euglenoids wererecruited from scarce species in the natural community and became a large part of thebiomass in semi-steady state in all communities. High temporal and yield stabilitywas demonstrated in all communities during semi-steady state. Biochemicalcomposition (lipids, proteins and carbohydrates) was similar for the threecommunities with lipids ranging 14-26 % of dry weight (DW), proteins (15-28 %DW) and carbohydrates (9-23 % DW). Filamentous cyanobacteria were outcompetedearly in the experiment. However, their minute presence in Cyano associated withhigher lipid and lower carbohydrates compared to Diatom and Green, suggesting theimportance of chemical interactions among microorganisms. Our results indicate thatculture functions (stability, biomass quality) were maintained while dynamic changesoccurred in community composition. We propose that a multi-species communityapproach can aid sustainability in microalgal cultivation, through complementary useof resources and higher culture stability. Local environmental conditions,complementary microalgal traits, and interactions among functional groups (algae,bacteria) should be considered in community design where natural succession andcrop rotation will likely provide stability for commercial-scale algal cultivation.

  • 92.
    Paczkowska, J
    et al.
    Umeå University ; Umeå Marine Science Centre.
    Rowe, OF
    Umeå University ; Umeå Marine Science Centre ; University of Helsinki, Finland.
    Schlüter, L
    DHI Water & Environment, Denmark.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Karlson, B
    Swedish Meteorological and Hydrological Institute.
    Andersson, A
    Umeå University ; Umeå Marine Science Centre.
    Allochthonous matter: an important factor shaping the phytoplankton community in the Baltic Sea2017In: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 39, no 1, p. 23-34Article in journal (Refereed)
    Abstract [en]

    It is well-known that nutrients shape phytoplankton communities in marine systems, but in coastal waters allochthonous dissolved organic matter (ADOM) may also be of central importance. We studied how humic substances (proxy of ADOM) and other variables influenced the nutritional strategies, size structure and pigment content of the phytoplankton community along a south–north gradient in the Baltic Sea. During the summer, the proportion of mixotrophs increased gradually from the phosphorus-rich south to the ADOM-rich north, probably due to ADOM-fueled microbes. The opposite trend was observed for autotrophs. The chlorophyll a(Chl a): carbon (C) ratio increased while the levels of photoprotective pigments decreased from south to north, indicating adaptation to the darker humic-rich water in the north. Picocyanobacteria dominated in phosphorus-rich areas while nanoplankton increased in ADOM-rich areas. During the winter–spring the phytoplankton biomass and concentrations of photoprotective pigments were low, and no trends with respect to autotrophs and mixotrophs were observed. Microplankton was the dominant size group in the entire study area. We conclude that changes in the size structure of the phytoplankton community, the Chl a:C ratio and the concentrations of photoprotective pigments are indicative of changes in ADOM, a factor of particular importance in a changing climate.

  • 93. Peperzak, L
    et al.
    Sandee, B
    Jonker, R
    Legrand, Catherine
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Measurement of Prorocentrum micans growth rates by flow analysis of the diel DNA cycle1998In: Intergovernmental Oceanographic Commission of UNESCO, Paris, 1998 / [ed] Reguera I et al, Vigo, Spain, 1998Conference paper (Refereed)
  • 94.
    Persson, Karl-Johan
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Bergström, Kristofer
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Mazur Marzec, Hanna
    University of Gdansk, Poland.
    Legrand, Catherine
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Differential tolerance to cyanobacterial exposure between geographically distinct populations of Perca fluviatilis2013In: Toxicon, ISSN 0041-0101, E-ISSN 1879-3150, no 76, p. 178-186Article in journal (Refereed)
    Abstract [en]

    Toxic cyanobacterial blooms are an important problem worldwide. Cyanobacteria may negatively impact young-of-the-year (YOY) fish directly (toxin production, turbidity, decrease in water quality) or indirectly (trophic toxin transfer, changes in prey species composition). Here we test whether there are any differences in cyanobacterial tolerance between four geographically distinct populations of European perch (Perca fluviatilis). We show that P. fluviatilis may develop tolerance against cyanobacteria demonstrated by the ability of individuals from a marine site (exposed to annual cyanobacterial blooms) to increase their detoxification more than individuals from an oligotrophic site (rarely exposed to cyanobacteria). Our results also revealed significant interaction effects between genotypes within a population and response to cyanobacterial exposure in terms of absolute growth and detoxification activity. This genotype by treatment interaction may result in local adaptations to cyanobacterial exposure in P. fluviatilis. Hence, the sensitivity against cyanobacterial exposure may differ between within species populations increasing the importance of local management of fish populations.

  • 95.
    Persson, Karl-Johan
    et al.
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Bergström, Kristofer
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Mazur Marzec, Hanna
    University of Gdansk, Poland.
    Legrand, Catherine
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Differential tolerance to cyanobacterial exposure between geographically distinct populations of Perca fluviatilis2013In: Toxicon, ISSN 0041-0101, E-ISSN 1879-3150, no 76, p. 178-186Article in journal (Refereed)
    Abstract [en]

    Toxic cyanobacterial blooms are an important problem worldwide. Cyanobacteria may negatively impact young-of-the-year (YOY) fish directly (toxin production, turbidity, decrease in water quality) or indirectly (trophic toxin transfer, changes in prey species composition). Here we test whether there are any differences in cyanobacterial tolerance between four geographically distinct populations of European perch (Perca fluviatilis). We show that P. fluviatilis may develop tolerance against cyanobacteria demonstrated by the ability of individuals from a marine site (exposed to annual cyanobacterial blooms) to increase their detoxification more than individuals from an oligotrophic site (rarely exposed to cyanobacteria). Our results also revealed significant interaction effects between genotypes within a population and response to cyanobacterial exposure in terms of absolute growth and detoxification activity. This genotype by treatment interaction may result in local adaptations to cyanobacterial exposure in P. fluviatilis. Hence, the sensitivity against cyanobacterial exposure may differ between within species populations increasing the importance of local management of fish populations.

  • 96.
    Persson, Karl-Johan
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Legrand, Catherine
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsson, Thomas
    Toxicon, Sweden.
    Detection of nodularin in European flounder (Platichthys flesus) in the west coast of Sweden: evidence of nodularin mediated oxidative stress2009In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 8, no 6, p. 832-838Article in journal (Refereed)
    Abstract [en]

    The brackish, bloom-forming cyanobacterium Nodularia spumigena produces a peptide called nodularin, which may induce liver damage in fish. In the summer of 2007, nodularin was detected in liver tissue of European flounder caught in Swedish waters of Öresund, within the upper salinity limit for N. spumigena. Nodularinconcentrations ranging between 22 and 557 μg kg−1 liver (d.w.) were detected in fish liver. Nodularin was not detected in blue mussels (Mytilus edulis). Although N. spumigena blooms can occur in the area, the cyanobacteria were only present in very small amounts in 2007. Results suggested that nodularin accumulated inflounder livers during the summer of 2006, when vast N. spumigena blooms were observed in Öresund, and persisted over several months. Nodularin has previously been shown to induce oxidative stress in mice, crustaceans and mollusks but work on the potential negative effects of nodularin on fish is still scarce. To examine the dynamics of nodularin induced oxidative stress in liver tissue of flounder, the differential responses of the antioxidant enzymes glutathione-S-transferase catalase(CAT) and the formation of malondialdehyde (MDA) were monitored during 14 days in flounder exposed to an intraperitoneal injection of nodularin (0, 2, 10 and 50 μg nodularin kg−1 body weight). The activities of GST and CAT in the liver decreased significantly in the 50 μg nodularin kg−1 exposure after 7 days, but were restored to control levels after an additional 10 days of recovery. The results suggested that nodularin induced oxidative stress in terms of decreased GST and CATactivity, which can result in increased vulnerability of the cell to reactive oxygen species (ROS). No significant changes could be found in MDA levels between the treatments. Thus, the antioxidant defense system presumably managed to prevent oxygen mediated toxicity as seen by the unchanged levels of MDA. Alteration of the enzymatic defense system may increase energetic costs, thus reducing fish growth and survival. The present study also suggests that oxidative stress biomarkers can be used in fish to detect early responses to nodularin.

  • 97.
    Persson, Karl-Johan
    et al.
    Linnéuniversitetet, Institutionen för naturvetenskap, NV.
    Stenroth, Patrik
    Linnéuniversitetet, Institutionen för naturvetenskap, NV.
    Legrand, Catherine
    Linnéuniversitetet, Institutionen för naturvetenskap, NV.
    Effects of the filamentous cyanobacterium Nodularia on fitness and feeding behavior of young-of-the-year (YOY) Eurasian perch (Perca fluviatilis)2011In: Toxicon, ISSN 0041-0101, E-ISSN 1879-3150, Vol. 57, no 7-8, p. 1033-1040Article in journal (Refereed)
    Abstract [en]

    AbstractThis study reveals that both cyanobacterial toxicity and turbidity have the potential to reduce the growth and energy storage of young-of-the-year (YOY) perch and thereby influence survival rates. During the 1990's a reduction in recruitment of YOY perch (Perca fluviatilis) occurred along the Swedish East coast. Concurrently, large blooms of filamentous cyanobacteria have increased in the Baltic Proper and in coastal waters. This study examined whether extended exposure to toxic and non-toxic filamentous cyanobacterium Nodularia affect YOY perch growth and feeding behavior under simulated bloom conditions (30 days at 50 μg Chl a L−1). Specific growth rate (SGR), the somatic condition index (SCI) and the lipid content of YOY perch (10–12 weeks old) were significantly lower in perch exposed to Nodularia compared to fed controls (no Nodularia). YOY perch exposed to non-toxic Nodularia displayed a higher attack rate than perch living in Nodularia free controls in 2 out of 3 trials. Reductions in growth and energy storage, mediated by cyanobacteria, increase the risk of starvation and predation and could locally influence recruitment of YOY perch.

    Highlights► We investigate the effects of toxic and non-toxic cyanobacterial (Nodularia sp.) on young-of-the-year (YOY) perch (Perca fluviatilis). ► Endpoints are specific growth rate (SGR), lipid content and feeding behavior (feeding and attack rate). ► Results show that both non-toxic and toxic Nodularia reduce SGR and lipid content of YOY perch. ► Reduced growth and energy storage may locally influence recruitment of YOY perch. 

  • 98.
    Persson, Karl-Johan
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Stenroth, Patrik
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Legrand, Catherine
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Effects of the filamentous cyanobacterium Nodularia on fitness and feeding behavior of young-of-the-year (YOY) Eurasian perch (Perca fluviatilis)2011In: Toxicon, ISSN 0041-0101, E-ISSN 1879-3150, Vol. 57, no 7-8, p. 1033-1040Article in journal (Refereed)
    Abstract [en]

    AbstractThis study reveals that both cyanobacterial toxicity and turbidity have the potential to reduce the growth and energy storage of young-of-the-year (YOY) perch and thereby influence survival rates. During the 1990's a reduction in recruitment of YOY perch (Perca fluviatilis) occurred along the Swedish East coast. Concurrently, large blooms of filamentous cyanobacteria have increased in the Baltic Proper and in coastal waters. This study examined whether extended exposure to toxic and non-toxic filamentous cyanobacterium Nodularia affect YOY perch growth and feeding behavior under simulated bloom conditions (30 days at 50 μg Chl a L−1). Specific growth rate (SGR), the somatic condition index (SCI) and the lipid content of YOY perch (10–12 weeks old) were significantly lower in perch exposed to Nodularia compared to fed controls (no Nodularia). YOY perch exposed to non-toxic Nodularia displayed a higher attack rate than perch living in Nodularia free controls in 2 out of 3 trials. Reductions in growth and energy storage, mediated by cyanobacteria, increase the risk of starvation and predation and could locally influence recruitment of YOY perch.

    Highlights► We investigate the effects of toxic and non-toxic cyanobacterial (Nodularia sp.) on young-of-the-year (YOY) perch (Perca fluviatilis). ► Endpoints are specific growth rate (SGR), lipid content and feeding behavior (feeding and attack rate). ► Results show that both non-toxic and toxic Nodularia reduce SGR and lipid content of YOY perch. ► Reduced growth and energy storage may locally influence recruitment of YOY perch. 

  • 99. Rathi, Akshat
    Olofsson, Martin (Contributor)
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    The revolutionary technology pushing Sweden toward the seemingly impossible goal of zero emissions: The cure for emissions: algae2017In: Quartz, no 21 JuneArticle in journal (Other (popular science, discussion, etc.))
  • 100. Rengefors, K
    et al.
    Legrand, Catherine
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Toxicity in Peridinium aciculiferum—an adaptive strategy to outcompete other winter phytoplankton?2001In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 46, no 8, p. 1990-1997Article in journal (Refereed)
    Abstract [en]

    Freshwater dinoflagellates may form dense blooms during winter in ice-covered lakes. Unlike their marine counterparts, freshwater dinoflagellates are rarely considered to be potential toxin producers. Here we tested whether the winter species Peridinium aciculiferum produces a toxin(s) and investigated the potential adaptive function of that toxin, i.e., predator defense or inhibition of competitors (allelopathy). Using traditional toxicity bioassays (Artemia toxicity test and hemolytic activity assay). we detected the production of a toxic substance by P. aciculiferum cells from both the field and from laboratory cultures. Cultures deprived of phosphorus and in stationary phase showed highest toxicity. Potential predators, such as Daphnia galeata (Cladocera) and Eudiaptomus graciloides (Copepoda), were apparently not harmed by P. aciculiferum toxicity. However, the naturally coaccurring competitor Rhodomonas lacustris (Cryptophyceae) was killed by P. aciculiferum. An allelopathic substance(s) caused the cells of R. lacustris to form blisters and subsequently lyse. We concluded that our results support the hypothesis that P. aciculiferum is allelopathic, but not that toxins serve as predator defense. We therefore suggest that allelopathy may be an adaptive strategy of winter dinoflagellates, which could allow them to outcompete other phytoplankton species and thereby dominate the algal biomass.

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