产甲烷
甲烷菌
产酸作用
甲烷八叠球菌
产甲烷菌
乙酸化
生物
微生物种群生物学
甲烷杆菌
微生物学
厌氧消化
细菌
甲烷
生态学
遗传学
作者
Renjie Ni,Chenming Xu,Xianyang Shi,Yang Shu,Lei Li,Xiangjun Peng,Liyan Song
标识
DOI:10.1016/j.jclepro.2022.133758
摘要
Anaerobic digestion (AD) is a microbial-mediated biogeochemical process that includes hydrolysis, acidogenesis, acetogenesis and methanogenesis. AD instability usually occurs in the transition from the acidogenesis phase (AP) to the methanogenesis phase (MP) due to over acidification. However, the underlying microbial mechanism of this transition has not been well characterized. In the present study, the transition of bacterial and methanogenic community composition, methanogenesis functional gene expression and metabolic pathways from AP to MP during food waste (FW) AD were investigated in a bioreactor using metagenomics and reverse transcription PCR technology. AP and MP were identified by changes in methane production, gas accumulation, pH and volatile fatty acids (VFAs). Concomitant with the changes in these physiochemical parameters, the bacterial and methanogenic community composition showed succession patterns. The bacterial composition transformed from acidogenic bacteria (Propionispira and Bacteroides) to hydrolytic bacteria (Smithella, Syntrophus and Syntrophorhabdus), and the methanogen composition transformed from the domination of acetoclastic methanogens (Methanosaeta) to the codomination of hydrogenotrophic methanogens (Methanoculleus, Methanolinea and Methanobacterium) and acetoclastic methanogens (Methanosaeta). The expression level of the methanogenesis functional gene mcrA significantly (p < 0.05) increased in response to the increasing methane production. In contrast, acetoclastic methanogenesis as the main methanogenesis metabolic pathway remained stable. These results showed that FWAD key physiochemical parameters drive the variation in microbial community composition and functional genes expression but not the methanogenesis metabolic pathway. The finding suggests that FWAD process may be better predicted by methanogenic functional characteristics than by microbial community composition.
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