添加钴元素牛粪沼气系统的产气特性及细菌多样性

Bacterial Diversity and Aerogenesis Characteristics of the Cow Dung Biogas System Added with Co^(2+)

为了解不同钴元素添加量对牛粪沼气发酵系统产气特性以及细菌群落结构的影响,通过构建细菌16SrRNA基因的克隆文库并对其中代表克隆进行系统发育分析和统计分析,研究了添加钴元素的牛粪沼气发酵系统中的细菌多样性。结果表明:添加钴元素会明显提高沼气发酵系统产甲烷性能,其中0.10mg/(L·d)的钴元素添加量所对应甲烷的产气量最高,为1 189mL,占总产气量的66%。在添加钴元素的牛粪沼气中共获得840个有效克隆,可划分为21个可操作分类单元(OTU),分属于厚壁菌门(Firmicutes)、变形杆菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)和绿弯菌门(Chloroflexi)。其中,ε-变形菌、拟杆菌和厚壁菌为优势类群,分别占细菌群落组成的39%、31%和22%。此外,BLAST分析的结果显示,试验探测到的部分细菌物种可能代表了属以上级别新的分类单元,而钴元素对细菌的群落结构并没有明显的影响。

The 16S rRNA gene phylogeny based on building the clone library of 16S rRNA gene was analyzed to study bacteria diversity,aerogenesis characteristics and bacteria community structure of the cow dung biogas system added with Co^2＋.Adding Co^2＋ can improve the methanogenesis performance of the biogas fermentation system significantly. The methanogenesis amount of the biogas fermentation system adding 0.10 mg/（L· d ）Co^2＋ was up to 1 189 mL （the highest）,accounting for 66% of total aerogenesis amount.840 effective clones obtained from the cow dung biogas system added with Co^2＋ can be divided into 2 1 operability taxon units （OTU）belonging to Firmicutes,Proteobacteria,Bacteroidetes and Chloroflexi.Epsilonproteobacteria,Bacteroidetes and Firmicutes were the dominant bacterial groups, accounting for 39%,31% and 22% of total bacteria community structure respectively.The BLAST analysis indicates that part bacterial species may represent new taxon units over genus but Co^2＋ has no obvious effect on bacterial community structure.