Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Biochemical Interactions of Some Saproxylic Fungi
Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
2015 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Interactions are all around us, and as humans we may use words and gestures to communicate our intentions. At the micro level of fungi, communications are replaced by chemical signals and structure. These interactions fall into three distinctive categories: synergistic, where organisms help each other, as is the case with ectomycorrhizal fungi and tree roots, deadlock, or combat, where organisms fight for or defend a resource. When it comes to fungi-tree interactions, the fungi group of basidiomycetes fall into the latter category. At the onset of fungal infection, a living tree defends itself by producing resinous substances such as terpenes. These compounds are frequently found in hydrodistilled turpentine, which makes turpentine a prime source of antifungal compounds. A D-optimal design of fractionated turpentine together with gas chromatography (GC) coupled to a mass spectrometer was employed to find the most biologically active constituent of turpentine. Growth rate of Coniophora puteana was used to assess the efficacy of the mixed fractions. The partial least squares projection model had an excellent predictive power (R2 = 0.988, Q2 = 0.825) and validity. A putative sesquiterpene was identified as the most active compound for inhibiting fungal growth. The model was corroborated by an external validation assay employing preparative GC. After the death of a tree, fungi are no longer hindered by secondary metabolites from the tree. Instead, other interspecies interactions and intraspecies interactions, such as fungi-fungi interactions, occur. We found that when the white-rot fungus Heterobasidion parviporum and brown-rot fungus Gloeophyllum sepiarium interact with each other, amino acids are used to a higher extent. Amino acids may be used to produce antifungal compounds to hinder the other species from growing. Lysine in particular was utilized to a greater extent during interaction. Glutamine was the only amino acid that increased in concentration. Glutamine might be exuded or converted by enzymes from already existing glutamic acid. Dry weights suggest that the fungi were in a deadlock and that nutrient limitation might be a determining factor. It seemed that H. parviporum was favoured by a decrease in pH while the opposite pattern may be true for G. sepiarium.

Place, publisher, year, edition, pages
Sundsvall: Mid Sweden University , 2015. , 34 p.
Series
Mid Sweden University licentiate thesis, ISSN 1652-8948 ; 116
Keyword [en]
biologically active compounds, bioactive, fungi-fungi interaction, fungi co-culture, extracellular amino acids.
National Category
Biological Sciences
Identifiers
URN: urn:nbn:se:miun:diva-25068ISBN: 978-91-88025-12-8 (print)OAI: oai:DiVA.org:miun-25068DiVA: diva2:816285
Supervisors
Available from: 2015-06-03 Created: 2015-06-03 Last updated: 2015-06-03Bibliographically approved
List of papers
1. Combinatorial Retention-Activity Relationship of Fractionated Turpentine on Fungal Growth
Open this publication in new window or tab >>Combinatorial Retention-Activity Relationship of Fractionated Turpentine on Fungal Growth
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Essential oils from plants are often used in growth inhibition assays against bacteria, fungi, insects and viral infections. Turpentine from Norway spruce (Picea abies) is an essential oil produced in large quantities as a waste product in paper production. It is a complex mixture of secondary metabolites that is rich in terpenes and terpenoids. These compounds protect the tree from fungal and bacterial infection; turpentine should therefore be a good source for biologically active substances for inhibiting fungal growth. In this study, a combination of a reductive and a holistic approach was employed to find the most inhibiting compound; an approach that we have called an intermistic approach. The most inhibiting compounds was determined in three steps against growth of the saproxylic fungus Coniophora puteana: rejecting half of the turpentine search space in a reductive manner, finding the optimal concentration and finally combining fractions of the most active half of turpentine in a quadratic D-optimal design to investigate it holistically. Multivariate data analysis of gas chromatography coupled with mass spectrometry (GC-MS) chromatograms was used to zoom in on the most active compounds responsible for antifungal activity. The growth rate of C. puteana in mm/day was used as y-variable and the relative area percentage of 36 GC-MS peaks from the mixtures was used as x-variables to construct a partial least squares (PLS) regression model. The final model was reduced to 12 peaks and used to find the most promising antifungal compound within the mixture. In addition, an external validation was performed with preparatory GC on the most active fraction. From the model, one putative sesquiterpene was identified along with at least two other sesquiterpenes and one diterpene warrant further investigation. Herein, a general method for finding biologically active compounds against wood-rotting fungi, and potentially other organisms from a complex mixture, is proposed.

National Category
Biological Sciences
Identifiers
urn:nbn:se:miun:diva-25066 (URN)
Available from: 2015-06-03 Created: 2015-06-03 Last updated: 2016-09-29Bibliographically approved
2. Changes in Extracellular Amino Acids, pH and Growth when Fungi Interact at the Near-contact Level: Heterobasidion parviporum vs. Gloeophyllum sepiarium
Open this publication in new window or tab >>Changes in Extracellular Amino Acids, pH and Growth when Fungi Interact at the Near-contact Level: Heterobasidion parviporum vs. Gloeophyllum sepiarium
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Heterobasidion parviporum and Gloeophyllum sepiarium are fungal species representing two different ecological niches. H. parviporum is a parasitic white-rot fungus and early colonizer of felled wood, while the brown-rot fungus G. sepiarium is an early-middle colonizer in the natural fungi succession order. In this study, we quantitatively examined the utilization of amino acids in the μM range, pH and final dry weight from common liquid glucose-malt extract medium when the two fungi were interacting at the near-contact level. An increase in glutamine concentration was observed, and lysine was utilized in a greater extent when fungi were interacting compared to when they grew on their own. Our results also show fungal interaction is a process with high variability both in pH, growth and amino acid utilization, depending on the type of interaction. A connection between the growth, according to dry weight, and pH is suggested in the interaction between H. parviporum and G. sepiarium.

National Category
Biological Sciences
Identifiers
urn:nbn:se:miun:diva-25067 (URN)
Available from: 2015-06-03 Created: 2015-06-03 Last updated: 2016-09-29Bibliographically approved

Open Access in DiVA

fulltext(957 kB)251 downloads
File information
File name FULLTEXT01.pdfFile size 957 kBChecksum SHA-512
1e383fa7910d001ab2bb1a5eb797806ee8eeec983b2a8b7228b9680ff742cb5bddfff9788c3422f0f78866c3189bdc73ea55532d186132ef6886da9ac7999df3
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Ljunggren, Joel
By organisation
Department of Natural Sciences
Biological Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 251 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 828 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf