原料比例与接种量对猪粪秸秆厌氧干发酵产气率及微生物群落的影响

Effects of Raw Material Ratio and Inoculation Amount on Biogas Production and Microbial Community in Anaerobic Dry Fermentations of Pig Manure with Straw

为实现对厌氧干发酵的科学控制,在中温37℃±1℃条件下,文章以水稻秸秆和猪粪为原料,采用批式发酵试验,研究不同猪粪秸秆比例(VS质量比分别为1∶1;2∶1)和接种量(VS质量比分别为30%,40%,50%)对厌氧干发酵产气特性和微生物群落结构的影响。结果表明∶相同接种量下猪粪∶秸秆为1∶1的试验组甲烷累积产率均高于2∶1;猪粪∶秸秆为1∶1,接种量为50%的试验组启动最快,累积甲烷产率也最高,是该研究中原料配比与接种量的最佳组合,累积沼气产量和累积VS甲烷产率分别为6801.67 mL和127.07 mL·g-1 VS。发酵微生物优势细菌为梭菌属(Clostridium),主要包括Clostridium sensu stricto和Terrisporobacter;优势古菌为Methanobrevibacter、Methanoculleus和Methanomassiliicoccus,其中Methanoculleus为发酵后新增优势古菌。不同原料比例对细菌和古菌的群落结构和多样性影响均较小,但古菌群落结构对接种量较为敏感,古菌多样性在一定范围内也随接种量的增加而提高。

In order to realize the scientific control for anaerobic dry fermentation,batch fermentation tests were carried out under condition of 37℃±1℃with different ratio of rice straw and pig manure as raw materials(VS ratio of 1∶1,2∶1),and different inoculation rate(VS rate of 30%,40%and 50%),the gas production characteristics and microbial community structure in anaerobic dry fermentation were investigated.The results showed that,under the same inoculation rate,material ratio at 1∶1(pig manure∶rice straw)resulted in a higher cumulative methane yield than that at ratio of 2∶1.And under the material ratio of 1∶1,the 50%inoculation group started up the fastest and had the highest cumulative methane yield,the cumulative biogas production was 6801.67 mL,and per unit VS methane yield was 127.07 mL·g-1,so,it was the best combination in this study.The dominant bacteria genus was Clostridium,including Clostridium sensu stricto and Terrisporobacter.The dominant archaea were Methanobrevibacter,Methanoculleus and Methanomassiliicoccus,among them,Methanoculleus is the newly revealed dominant archaea after fermentation.Different proportions of raw materials had little influence on the community structure and diversity of bacteria and archaea,but the community structure of archaea was more sensitive to the inoculation amount,and the diversity of archaea also increased with the increase of inoculation amount in a certain range.