Methanogenic community shift and comparison were determined by 454 pryosequencing for two different full-scale anaerobic digesters treating municipal sludge. For monitoring long-term of microbial communities, samples were collected for two year at three-monthly basis. The two mesophilic AD bioreactor were operated at similar operating conditions, but different substrate streams. Methanospirillum were identified as the key drivers of methanogenesis in full-scale anaerobic digester treating municipal sludge. In Joongrang (JR) digester, Methanospirillum was dominant (48%±10.3) over almost all period, but the dominant genus move to Methanosaeta and Methanoculleus due to low acetate concentration (0.02 g/L), total ammonia nitrogen concentration, respectively. In Asan digester (AS), Methanospirillum also was dominant (41%±12.6) like JR digester, but methanogenic community shift was examined twice. One of those was from Methanospirillum to Methanophaerula due to pH sharply decrease (<5.5) and second shift was Methanosaeta increase due to low VFAs concentration (0.25 g/L).

• Taewoan Koo(School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH))
• Seung Gu Shin(School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH))
• Joonyeob Lee(School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH))
• Seokhwan Hwang(School of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH))