umu.sePublikationer
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Extreme zinc tolerance in acidophilic microorganisms from the bacterial and archaeal domains
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet). (Mark Dopson)
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet). Aberdeen Fungal Group, University of Aberdeen, Scotland, UK.
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
Visa övriga samt affilieringar
2013 (Engelska)Ingår i: Extremophiles, ISSN 1431-0651, E-ISSN 1433-4909, Vol. 17, nr 1, s. 75-85Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Zinc can occur in extremely high concentrations in acidic, heavy metal polluted environments inhabited by acidophilic prokaryotes. Although these organisms are able to thrive in such severely contaminated ecosystems their resistance mechanisms have not been well studied. Bioinformatic analysis of a range of acidophilic bacterial and archaeal genomes identified homologues of several known zinc homeostasis systems. These included primary and secondary transporters, such as the primary heavy metal exporter ZntA and Nramp super-family secondary importer MntH. Three acidophilic model microorganisms, the archaeon 'Ferroplasma acidarmanus', the Gram negative bacterium Acidithiobacillus caldus, and the Gram positive bacterium Acidimicrobium ferrooxidans, were selected for detailed analyses. Zinc speciation modeling of the growth media demonstrated that a large fraction of the free metal ion is complexed, potentially affecting its toxicity. Indeed, many of the putative zinc homeostasis genes were constitutively expressed and with the exception of 'F. acidarmanus' ZntA, they were not up-regulated in the presence of excess zinc. Proteomic analysis revealed that zinc played a role in oxidative stress in At. caldus and Am. ferrooxidans. Furthermore, 'F. acidarmanus' kept a constant level of intracellular zinc over all conditions tested whereas the intracellular levels increased with increasing zinc exposure in the remaining organisms.

Ort, förlag, år, upplaga, sidor
2013. Vol. 17, nr 1, s. 75-85
Nyckelord [en]
Acid mine drainage, Acidophile, Metal resistance, Modeling, Zinc
Nationell ämneskategori
Mikrobiologi
Identifikatorer
URN: urn:nbn:se:umu:diva-60634DOI: 10.1007/s00792-012-0495-3ISI: 000312779200007PubMedID: 23143658OAI: oai:DiVA.org:umu-60634DiVA, id: diva2:561760
Tillgänglig från: 2012-10-22 Skapad: 2012-10-22 Senast uppdaterad: 2018-06-08Bibliografiskt granskad
Ingår i avhandling
1. Growth and survival of Acidithiobacilli in Acidic, metal rich environments
Öppna denna publikation i ny flik eller fönster >>Growth and survival of Acidithiobacilli in Acidic, metal rich environments
2012 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Alternativ titel[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.

Ort, förlag, år, upplaga, sidor
Umeå: Umeå Universitet, 2012. s. 70
Nationell ämneskategori
Mikrobiologi
Identifikatorer
urn:nbn:se:umu:diva-60439 (URN)978-91-7459-474-4 (ISBN)
Disputation
2012-11-23, NUS - Norrlands universitetssjukhus, 933 Unod B9, Norrlands universitetssjukhus, Umeå, 09:00
Opponent
Handledare
Tillgänglig från: 2012-11-02 Skapad: 2012-10-11 Senast uppdaterad: 2018-06-08Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltextPubMed

Personposter BETA

Mangold, StefaniePotrykus, JoannaBjörn, ErikLövgren, LarsDopson, Mark

Sök vidare i DiVA

Av författaren/redaktören
Mangold, StefaniePotrykus, JoannaBjörn, ErikLövgren, LarsDopson, Mark
Av organisationen
Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet)Kemiska institutionen
I samma tidskrift
Extremophiles
Mikrobiologi

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
pubmed
urn-nbn

Altmetricpoäng

doi
pubmed
urn-nbn
Totalt: 315 träffar
RefereraExporteraLänk till posten
Permanent länk

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