Biological pretreatment enhances the activity of functional microorganisms and the ability of methanogenesis during anaerobic digestion

• Published in: Bioresource technology Vol. 290; p. 121660
• Main Authors: Zhao, Yiquan, Xu, Congfeng, Ai, Shiqi, Wang, Haipeng, Gao, Yamei, Yan, Lei, Mei, Zili, Wang, Weidong
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-10-2019
• Subjects: Anaerobic digestion; Biological pretreatment; Community structure; Methanogenic archaea; Microbial activity; Community structure; Microbial activity; Methanogenic archaea; Anaerobic digestion; Biological pretreatment
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121660

•The community structural stability in AD ensures the feasibility of pretreatment.•Pretreatment raises the methanogenic efficiency by affecting the active community.•The dominant methanogenic archaea during pretreatment were Methanosaeta.•The methane production was increased via the effort of two methanogenic pathways.
Biological pretreatment can increase the methane production of anaerobic digestion. In this study, stover was pretreated via microbial consortium prior to anaerobic digestion; through 16S rRNA gene and 16S rRNA amplicon sequencing and metatranscriptomic analysis, and the effects of the pretreatment on the microbial community and critical factors of the increased methane production were studied. Microbial community structure was less affected by the pretreatment, which ensures the stable performance of anaerobic digestion. The methane production increased by 62.85% at the peak phase compared to the untreated stover. The activity of Methanosaeta increased from 2.0% to 10.1%, significantly enhancing the ability of the community to capture acetic acid and reduce CO2 to methane. The main contribution to the increase in methane production was a unique acetyl-CoA synthetase, which showed significant up-regulation (121.8%). This research demonstrated the importance of Methanosaeta and its unique metabolic pathways in anaerobic digestion utilizing a biological pretreatment.