Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Sulfur metabolism in the extreme acidophile acidithiobacillus caldus
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
2011 (engelsk)Inngår i: Frontiers in microbiology, ISSN 1664-302X, Vol. 2, s. 17-Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Given the challenges to life at low pH, an analysis of inorganic sulfur compound (ISC) oxidation was initiated in the chemolithoautotrophic extremophile Acidithiobacillus caldus. A. caldus is able to metabolize elemental sulfur and a broad range of ISCs. It has been implicated in the production of environmentally damaging acidic solutions as well as participating in industrial bioleaching operations where it forms part of microbial consortia used for the recovery of metal ions. Based upon the recently published A. caldus type strain genome sequence, a bioinformatic reconstruction of elemental sulfur and ISC metabolism predicted genes included: sulfide-quinone reductase (sqr), tetrathionate hydrolase (tth), two sox gene clusters potentially involved in thiosulfate oxidation (soxABXYZ), sulfur oxygenase reductase (sor), and various electron transport components. RNA transcript profiles by semi quantitative reverse transcription PCR suggested up-regulation of sox genes in the presence of tetrathionate. Extensive gel based proteomic comparisons of total soluble and membrane enriched protein fractions during growth on elemental sulfur and tetrathionate identified differential protein levels from the two Sox clusters as well as several chaperone and stress proteins up-regulated in the presence of elemental sulfur. Proteomics results also suggested the involvement of heterodisulfide reductase (HdrABC) in A. caldus ISC metabolism. A putative new function of Hdr in acidophiles is discussed. Additional proteomic analysis evaluated protein expression differences between cells grown attached to solid, elemental sulfur versus planktonic cells. This study has provided insights into sulfur metabolism of this acidophilic chemolithotroph and gene expression during attachment to solid elemental sulfur.

sted, utgiver, år, opplag, sider
Frontiers Media , 2011. Vol. 2, s. 17-
HSV kategori
Identifikatorer
URN: urn:nbn:se:umu:diva-56532DOI: 10.3389/fmicb.2011.00017PubMedID: 21687411OAI: oai:DiVA.org:umu-56532DiVA, id: diva2:535574
Tilgjengelig fra: 2012-06-20 Laget: 2012-06-20 Sist oppdatert: 2018-06-08bibliografisk kontrollert
Inngår i avhandling
1. Growth and survival of Acidithiobacilli in Acidic, metal rich environments
Åpne denne publikasjonen i ny fane eller vindu >>Growth and survival of Acidithiobacilli in Acidic, metal rich environments
2012 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Alternativ tittel[sv]
Tillväxt och överlevnad av Acidithiobacilli i sura, metallrika miljöer
Abstract [en]

Acidithiobacilli are acidophilic microorganisms that play important roles in many natural processes such as acidification of the environment, influencing metal mobility, and impacting on global sulfur and iron cycles. Due to their distinct metabolic properties they can be applied in the industrial extraction of valuable metals. Acidithiobacilli thrive in an environment which is extremely acidic and usually low in organic carbon but highly polluted with metals. In the quest to gain insight into how these microorganisms can thrive in their extreme environment, relevant facets of metabolism, metal resistance, and pH homeostasis were exploredwith the focus on two model organisms,

Acidithiobacillus caldus and Acidithiobacillus ferrooxidans. Understanding these fundamental aspects of an acidophilic lifestyle will help to eventually control detrimental effects on the environment due to acidification and metal pollution as well as improving metal extraction utilizing acidophilic microorganisms.

Bioinformatics can give information about the genetic capacity of an organism. Likewise, ‘omics’ techniques, such as transcriptomics and proteomics to study gene transcription profiles and differentially expressed proteins canyield insights into general responses as well as giving clues regarding specific mechanisms for adaptation to life in extreme environments. This approach was used to investigate the sulfur metabolism of

At. caldus which is an important sulfur oxidizer for industrial metal extraction. It was found that sulfur oxidation pathways were diverse within acidithiobacilli and a model of At. caldus sulfur oxidation was proposed. Furthermore, At. ferrooxidans anaerobic sulfur oxidation coupled to ferric iron reduction was studied which can be of importance for industrial processes. It was shown that anaerobic sulfur oxidation was, at least in part, indirectly coupled to ferric iron reduction via sulfide generation. Moreover, metal toxicity and resistance mechanisms in acidophiles are of major interest. Thus, zinc toxicity in three model organisms, At. caldus, Acidimicrobium ferrooxidans, and ‘Ferroplasma acidarmanus’, was explored. An important finding was that the speciation of metals and other chemical influences were of great importance for zinc toxicity in acidophiles. Additionally, the three organisms showed distinct responses to elevated zinc levels. Finally, the response of At. caldus to various suboptimal growth pH was evaluated to gain insights into pH homeostasis mechanisms. The results indicated that At. caldus used acid resistance mechanisms similar to those described for neutrophilic microorganisms. Analysis of fatty acid profiles demonstrated an active modulation of the cyctoplasmic membrane in response to proton concentration, likely resulting in a more rigid membrane at lower pH.

sted, utgiver, år, opplag, sider
Umeå: Umeå Universitet, 2012. s. 70
HSV kategori
Identifikatorer
urn:nbn:se:umu:diva-60439 (URN)978-91-7459-474-4 (ISBN)
Disputas
2012-11-23, NUS - Norrlands universitetssjukhus, 933 Unod B9, Norrlands universitetssjukhus, Umeå, 09:00
Opponent
Veileder
Tilgjengelig fra: 2012-11-02 Laget: 2012-10-11 Sist oppdatert: 2018-06-08bibliografisk kontrollert

Open Access i DiVA

fulltext(2893 kB)351 nedlastinger
Filinformasjon
Fil FULLTEXT02.pdfFilstørrelse 2893 kBChecksum SHA-512
1efa586f8de3b927a56f40d78d92b2d04a72939c9af52716b19cde146d1288a050cda1669b2a271270364a0846310c96764ec970a095e115ab2b6553a22bd1b5
Type fulltextMimetype application/pdf

Andre lenker

Forlagets fulltekstPubMed

Søk i DiVA

Av forfatter/redaktør
Mangold, StefanieDopson, Mark
Av organisasjonen

Søk utenfor DiVA

GoogleGoogle Scholar
Totalt: 351 nedlastinger
Antall nedlastinger er summen av alle nedlastinger av alle fulltekster. Det kan for eksempel være tidligere versjoner som er ikke lenger tilgjengelige

doi
pubmed
urn-nbn

Altmetric

doi
pubmed
urn-nbn
Totalt: 261 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf