ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Biofilm development plays a pivotal role in the bioleaching process. The attachment ofthe acidophilic chemolithotrophic Acidithiobacillus ferrooxidans to mineral surfaces is mediated byextracellular polymeric substances (EPS) involved in biofilm development. Previous work suggeststhat EPS composition of A. ferrooxidans is adapted to the energy source and, accordingly, thebacterium must be able to sense the surface to which attachment occurs with the consequenttriggering of the expression of different EPS-genes. Quorum sensing (QS) is recognized as one ofthe main regulators of biofilm formation. A. ferrooxidans possesses a functional QS type AI-1system and the analysis of culture supernatants revealed us that this bacterium is able to synthesizenine different homoserine lactones (AHLs) whose acyl-chain lengths oscillate between 8 and 16carbons and include an alcohol or a ketone function at the C3 position. The transcription levels ofthe afeI gene encoding for the AHL synthase are higher in cells grown in sulfur and thiosulfatemedia than in iron-grown cells, suggesting that biofilm formation in A. ferrooxidans would beregulated by the QS type AI-1 system. In the present study, the effect of several synthetic AHLsand analogues on the attachment of A. ferrooxidans to pyrite was analyzed. Preliminary resultssuggest that some of these molecules are changing the bacterial attachment to pyrite
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/39/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.20-21.345.pdf
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