Transcriptomic studies of capsular polysaccharide export systems involved in biofilm formation by Acidithiobacillus ferrooxidans
Bioleaching is the dissolution of metal sulfides, such as pyrite (FeS2) by bacterial oxidation processes. Selective attachment and biofilm formation on sulfidic mineral surfaces by Acidithiobacillus ferrooxidans is important for this process. Uronic acid residues present in the extracellular polymeric substances ( EPS) bind ferric ions. These bound ferric ions inherent in the EPS mediate attachment and also serve as the main oxidative agents for pyrite dissolution. Consequently, the EPS-matrix is a reaction space, coupling the bacterial respiratory chain with the chemical oxidation of pyrite. Bioinformatic analysis of At. ferrooxidans complete genome sequence revealed the presence of at least five gene clusters containing homologous genes of two different capsular polysaccharide export systems to those capsular polysaccharide ( CPS) biosynthesis and export systems described in E. coli and other Gramnegative bacteria. The presence of two genes homologous to wza, encoding an outer membrane polysaccharide export ( OPX) protein, suggests that at least two different types of polysaccharides could be exported. In this paper the expression patterns of cells grown on different energy sources were compared using quantitative RT-PCR of the respective RNA. Results show substrate and cell-population specific differences in gene expression patterns.
Acidithiobacillus ferrooxidans EPS biofilm formation metal sulfides bioleaching
Soren Bellenberg Mario Vera Wolfgang Sand
Biofilm Centre, Aquatic Biotechnology, University Duisburg-Essen Universitatsstr. 2, 45141, Essen, Germany
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
362-365
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）