发酵温度对青海农用沼气池微生物群落的影响

为了研究发酵温度对青海农用沼气池微生物群落结构的影响，以沼气池全年6个温度时期的24个泥样为研究对象，采用变性梯度凝胶电泳分析样品中细菌与古菌的群落结构及其变化差异.结果显示：发酵温度的波动变化对微生物群落结构、多样性及沼气池产气量影响显著.细菌在温度最高（九月中旬）和最低（三月中旬）的2个采样时期多样性最高，古菌仅在温度最高时期多样性最高.在细菌类群中，厚壁菌门Firmicutes、拟杆菌门Bacteroidetes和变形菌门Proteobacteria是所有样品中丰度最高的类群（三者总和>72.43%），是发酵系统中重要的功能细菌类群.细菌属分类水平上，理研菌科佩特里单胞菌属Petrimonas、梭菌属Clostridium、泰氏菌属Tissierella和假单胞菌属Pseudomona是所有样品的优势类群，总丰度比例较为恒定（约32.40%）.在古菌类群中，甲烷微菌目是最优势类群，丰度为40.62%~64.74%.产甲烷菌属Methanogenium是所有样品中主要的产气功能种群，丰度波动范围为32.62%~55.74%，随全年温度的变化而波动，此与沼气的产气规律相一致.

The effect of temperature on the microbial community of rural household biogas digesters in Qinghai Province

In order to investigate the effect of fermentation temperature on the microbial community structure of the rural household biogas digesters in Qinghai Province, twenty-four mud samples from six fermentation temperature periods through the year were collected and analyzed for their changes in microbial community structure using denaturing gradient gel electrophoresis (DGGE). Results showed that fermentation temperature had significant effects on the structure and diversity of microbial communities, and biogas production. Bacteria showed the highest species richness in both the highest (mid-September) and the lowest (mid-March) sampling temperature period, whereas archaea showed the highest species diversity only in mid-September. Firmicutes, Bacteroidetes and Proteobacteria were the most abundant bacterial phyla detected in all samples (total abundance > 72.43%), all of which are important functional bacterial groups in the fermentation system for biogas production. The genera of Petrimas, Clostridium, Tissierella and Pseudomona were the most dominant bacterial groups in all samples, whose total abundance was relatively constant (~32.40%). In archaea, the most dominant group among all samples was the order Methanomicrobiales, with relative abundance of 40.62%~64.74%. The genus Methanogenium was the most dominant species detected for biogas production. Its abundance changed regularly with the fluctuation of fermentation temperature within the range of 32.62%~55.74%, and was consistent with the regularity of biogas production.