褐煤本源菌在煤层生物气生成中的微生物学特征

Performance of indigenous bacteria during the biogenic gas generation from brown coal

为探明微生物菌群在褐煤生物气生成过程中的作用机制,利用厌氧手套箱为操作平台,从云南昭通盆地新鲜褐煤样品中富集培养本源产甲烷菌群,并通过褐煤生物气生成模拟实验,研究了产气过程中发酵细菌、产氢产乙酸菌数量和纤维素酶、辅酶F420活性的变化特征.结果表明:在生物气产生过程中,发酵细菌始终保持着较高活性(大于7.5×106个/mL),产氢产乙酸菌数量和增殖速率明显小于发酵细菌,但其数量变化趋势与发酵细菌相似,两者在营养生态位上显示出明显的承继关系;纤维素酶始终保持较高的活性(0.018～0.023mg/(mL.h));辅酶F420活性会受到产酸发酵菌所产生的酸性物质的抑制,其最低活性值为峰值的55.91%～67.61%;辅酶F420活性在褐煤生物气产出过程中经历了两个高峰期,指示着褐煤的煤层气生成过程具有阶段性.

In order to verify the functional mechanism of microbial community in biogenic gas generation progress from brown coal,we used anaerobic glove chamber as the experimental platform to enrich and cultivate active methanogen flora from freshly collected brown coal samples from Zhaotong basin,Yunnan Province,China.A simulating experiment of biogenic gas from brown coal was conducted with these indigenous bacteria.The amounts of fermentation and syntrophic acetogenic bacteria,and the activities of cellulase and coenzyme F420 were analyzed during the experiment.The results show that the fermentation bacteria kept quite active（≥7.5×106/mL） throughout the biogas generation process;and both the amount and breeding rate of syntrophic acetogenic bacteria were smaller than that of fermentation bacteria.But the amounts of both kinds of bacteria had the same changing trend,which shows significant inherited food chain-related relationship.The activities of cellulase remained fairly（0.018-0.023 mg/（mL·h））;while those of coenzyme F420 could have been inhibited by the acid substances created by acidogenic fermenting bacteria.The minimum activity values were 55.91%-67.61% of the peak values.The activities of coenzyme F420 had two peak times in the biogenic gas generation progress from brown coal,indicating periodic characteristics of biogenic coalbed methane generation from brown coal.