Institute of Biodiversity, Johann Heinrich von Thünen-Institut (vTI), Braunschweig, Germany.
Appl Microbiol Biotechnol. 2011 Mar;89(6):1991-2004. doi: 10.1007/s00253-010-2955-y. Epub 2010 Oct 31.
Microbial conversion of organic waste or harvested plant material into biogas has become an attractive technology for energy production. Biogas is produced in reactors under anaerobic conditions by a consortium of microorganisms which commonly include bacteria of the genus Clostridium. Since the genus Clostridium also harbors some highly pathogenic members in its phylogenetic cluster I, there has been some concern that an unintended growth of such pathogens might occur during the fermentation process. Therefore this study aimed to follow how process parameters affect the diversity of Bacteria in general, and the diversity of Clostridium cluster I members in particular. The development of both communities was followed in model biogas reactors from start-up during stable methanogenic conditions. The biogas reactors were run with either cattle or pig manures as substrates, and both were operated at mesophilic and thermophilic conditions. The structural diversity was analyzed independent of cultivation using a PCR-based detection of 16S rRNA genes and genetic profiling by single-strand conformation polymorphism (SSCP). Genetic profiles indicated that both bacterial and clostridial communities evolved in parallel, and the community structures were highly influenced by both substrate and temperature. Sequence analysis of 16S rRNA genes recovered from prominent bands from SSCP profiles representing Clostridia detected no pathogenic species. Thus, this study gave no indication that pathogenic clostridia would be enriched as dominant community members in biogas reactors fed with manure.
微生物将有机废物或收获的植物材料转化为沼气，已成为一种有吸引力的能源生产技术。沼气是在厌氧条件下由微生物群落产生的，这些微生物通常包括梭菌属的细菌。由于梭菌属在其系统发育群 I 中也有一些高度致病的成员，因此人们一直担心在发酵过程中可能会意外地生长出此类病原体。因此，本研究旨在研究工艺参数如何影响细菌的多样性，特别是梭菌属 I 成员的多样性。从模型沼气反应器的启动到稳定的产甲烷条件下，对两个群落的发展进行了跟踪。沼气反应器以牛或猪粪便作为底物运行，并且均在中温和高温条件下运行。使用基于 PCR 的 16S rRNA 基因检测和单链构象多态性（SSCP）进行遗传分析，对未培养的结构多样性进行了分析。遗传图谱表明，细菌和梭菌群落平行进化，群落结构受底物和温度的强烈影响。从 SSCP 图谱中代表梭菌的突出条带回收的 16S rRNA 基因序列分析未检测到致病种。因此，本研究表明，在以粪便为饲料的沼气反应器中，不会富集致病性梭菌作为优势群落成员。
