Division of Microbial Resources, Research Center for Chemistry, Biology and Agriculture (CPQBA), Campinas University (UNICAMP), CP 6171, Campinas, SP, CEP 13081-970, Brazil ,
World J Microbiol Biotechnol. 2013 Nov;29(11):2003-14. doi: 10.1007/s11274-013-1363-8. Epub 2013 Apr 30.
Biological hydrogen production through the anaerobic digestion is an environmental friendly alternative for satisfying future hydrogen demands. Microorganisms residing into waste water treatment plants are far from being exhaustively characterized and surveys on hydrogen production through FeFe-hydrogenase in such ecosystems are scarce. This study combined the analysis of 16S rRNA and [FeFe]-hydrogenase (hydA) genes with statistical tools to estimate richness and diversity of the microbial community of a domestic sewage treatment plant at the phylogenetic and functional levels. Archaeal groups were represented by 69 % of sequences assigned to Methanosarcinales and the remaining belonged to Methanomicrobiales. Within the bacterial library, 136 operational taxonomic units (OTUs) were distributed into 9 phyla, being 86 OTUs related to uncultivated bacteria. From these, 25 OTUs represented potential novel taxa within Synergistetes. Proteobacteria was the most predominant (36 % of the OTUs) and diversified phylogenetic group in the bacterial library, most of them assigned to the class Betaproteobacteria. Twenty-two putative hydA sequences were recovered into four distinct clusters and most of them were more closely related to each other than with sequences retrieved from databases, indicating they are hitherto undetected [Fe-Fe]-hydrogenase gene sequences. The richness estimates revealed that the number of sampled sequences was enough for full coverage of the archaeal diversity but not sufficient to cover both bacterial and hydA gene diversities. The results confirmed a great richness and diversity of bacterial and hydA sequences retrieved from the sewage sludge sample, suggesting such environment as a potential reservoir of new hydrogenase genes for biotechnological exploration.
通过厌氧消化进行生物制氢是满足未来氢气需求的一种环保替代方法。废水处理厂中的微生物远未被充分描述，而且在这种生态系统中通过 FeFe-氢化酶进行制氢的调查也很少。本研究结合了 16S rRNA 和 [FeFe]-氢化酶（hydA）基因的分析，并结合统计工具，从系统发育和功能水平上估计了污水处理厂微生物群落的丰富度和多样性。古菌组由分配给 Methanosarcinales 的序列的 69%代表，其余的属于 Methanomicrobiales。在细菌文库中，136 个操作分类单元（OTUs）分布在 9 个门中，其中 86 个 OTUs 与未培养的细菌有关。在这些 OTUs 中，有 25 个 OTUs 代表了 Synergistetes 中潜在的新分类群。变形菌是细菌文库中最主要的（36%的 OTUs）和多样化的系统发育群，其中大多数被分配到β变形菌纲。从污水污泥样本中回收了 22 个推定的 hydA 序列，它们分为四个不同的簇，其中大多数彼此之间的关系比与数据库中检索到的序列更密切，这表明它们是迄今未检测到的 [Fe-Fe]-氢化酶基因序列。丰富度估计表明，所采样的序列数量足以充分覆盖古菌的多样性，但不足以覆盖细菌和 hydA 基因的多样性。结果证实，从污水污泥样本中回收的细菌和 hydA 序列具有丰富的多样性，这表明这种环境可能是生物技术探索新氢化酶基因的潜在来源。
