Evolution of microbial community along with increasing solid concentration during high-solids anaerobic digestion of sewage sludge

• Published in: Bioresource technology Vol. 216; pp. 87 - 94
• Main Authors: Liu, Can, Li, Huan, Zhang, Yuyao, Si, Dandan, Chen, Qingwu
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2016
• Subjects: Anaerobic digestion; Anaerobiosis; Archaea - metabolism; Bacteria - metabolism; Biodiversity; Bioreactors - microbiology; Firmicutes; Methane - metabolism; Methanosarcina; Methanosarcina - metabolism; Microbial community; Phylogeny; Refuse Disposal - methods; Sewage - microbiology; Sewage sludge; Solid concentration; Solid concentration; Sewage sludge; Anaerobic digestion; Microbial community
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2016.05.048

•Microbial communities in high-solids sludge anaerobic digesters were investigated.•The dominant acetoclastic methanogen is Methanosarcina other than Methanosaeta.•Hydrogenotrophic and methylotrophic methanogens increased significantly.•Acidogenic and acetogenic bacteria decreased while proteolysis ones increased. High-solids anaerobic digestion (HSAD), a promising method with smaller reactor and less heating energy consumption, showed relatively lower digestion efficiency sometimes and higher tolerance to some inhibitors. To investigate the phenomena, the archaeal and bacterial communities in four anaerobic digesters treating sewage sludge with total solids (TS) of 10–19% were investigated. Although acetoclastic methanogenesis conducted mainly by genus Methanosarcina was still the main pathway producing methane, the total ratio of acetoclastic methanogens decreased along with the increased TS. In contrary, the relative abundance of hydrogenotrophic methanogens increased from 6.8% at TS 10% to 22.3% at TS 19%, and methylotrophic methanogens from 10.4% to 20.9%. The bacterial community was dominated by five phyla. Acidogenic and acetogenic bacteria affiliated to Firmicutes decreased following the increase of TS; while the proteolysis phylum Bacteroidetes increased, with a tolerant family ST-12K33 notably existing in the digesters at TS 17% and 19%.