Interdisciplinary Ecological Centre, TU Bergakademie Freiberg, Leipziger Straße 29, 09599, Freiberg, Germany.
Arch Microbiol. 2012 Jul;194(7):623-35. doi: 10.1007/s00203-011-0777-7. Epub 2012 Feb 21.
In the present study cultivation-dependent and molecular methods were applied in combination to investigate the arsenite-oxidizing communities in enrichment cultures from arsenic and lead smelter-impacted soils with respect to both 16S rRNA and arsenite oxidase gene diversity. Enrichments with arsenite as the only electron donor resulted in completely different communities than enrichments with yeast extract and the simultaneous presence of arsenite. The lithoautotrophic community appeared to be dominated by Ferrimicrobium-related Actinobacteria, unusual Acidobacteria, Myxobacteria, and α-Proteobacteria but the heterotrophic community comprised many Dokdonella-related γ-Proteobacteria. Gene sequences of clones encoding arsenite oxidase from the enrichment for lithoautotrophs belonged to three major clusters with sequences from non-cultivated microorganisms. So, primers used to detect arsenite oxidase genes could amplify the genes from many α-, β- and γ-Proteobacteria, but not from various strains of the other phyla present in the enrichment for lithotrophs. This was also observed for the isolates where arsenite oxidase genes from new proteobacterial isolates of the genera Burkholderia, Bosea, Alcaligenes, Bradyrhizobium and Methylobacterium could be amplified but the genes of the new Rhodococcus isolate S43 could not. The results indicate that the ability to oxidize arsenite is widespread in various unusual taxa, and molecular methods for their detection require further improvement.
在本研究中，结合培养依赖和分子方法，研究了砷和铅冶炼厂污染土壤中以亚砷酸盐为唯一电子供体的富集培养物中的亚砷酸盐氧化菌群，涉及 16S rRNA 和亚砷酸盐氧化酶基因多样性。与仅含亚砷酸盐的富集培养物相比，同时存在酵母提取物和亚砷酸盐的富集培养物中，会产生完全不同的群落。石生自养群落似乎主要由与 Ferrimicrobium 相关的放线菌、不常见的 Acidobacteria、粘细菌和α-Proteobacteria 主导，但异养群落则包含许多与 Dokdonella 相关的γ-Proteobacteria。来自石生自养富集物的编码亚砷酸盐氧化酶的克隆基因序列属于三个主要簇，序列来自未培养的微生物。因此，用于检测亚砷酸盐氧化酶基因的引物可以扩增来自许多α-、β-和γ-Proteobacteria 的基因，但不能扩增来自石生自养富集物中其他门的各种菌株的基因。这也适用于分离物，其中可以扩增来自 Burkholderia、Bosea、Alcaligenes、Bradyrhizobium 和 Methylobacterium 等新 Proteobacteria 分离物的亚砷酸盐氧化酶基因，但不能扩增新 Rhodococcus 分离物 S43 的基因。结果表明，氧化亚砷酸盐的能力广泛存在于各种不寻常的类群中，用于检测它们的分子方法需要进一步改进。
