title: Low-strength ultrasonication positively affects methanogenic granules toward higher AD performance: Implications from microbial community shift.
abstract: To elucidate the enhanced methane yield from organic wastes, the effects of low-strength ultrasonication on the microbial community structures in upflow anaerobic sludge blanket reactors were for the first time analyzed using pyrosequencing. Interestingly, a more even microbial community was observed in the ultrasonicated granules than in the control, which could compensate for the decreased richness and resulted in comparable (archaea) or even higher (bacteria) diversity. The ultrasonicated granules contained higher levels of δ-Proteobacteria, of which many are reportedly potential syntrophs, as well as methanogenic genera Methanosaeta, Methanotorris, and Methanococcus. The increased presence of syntrophic bacteria with their methanogenic partners was discussed with respect to hydrogen flux; their selective proliferation seems to be responsible for the enhanced anaerobic performance. This study is the first research shedding light on the novel function of low-strength ultrasound shifting the microbial structure towards better biogas production performance, and will facilitate application of low-strength ultrasound to other bioprocesses.
authors.affiliation: Department of Biological and Environmental Science, Dongguk University, 32 Dongguk-ro, Ilsandong-gu, Goyang, Gyeonggi-do, Republic of Korea.
authors.forename: Si-Kyung
authors.initials: SK
authors.lastname: Cho
authors.affiliation: Department of Civil Engineering, Inha University, 100 Inha-ro, Nam-gu, Incheon, Republic of Korea.
authors.forename: Dong-Hoon
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Warwick Medical School, University of Warwick, Coventry, United Kingdom.
authors.forename: Christopher
authors.initials: C
authors.lastname: Quince
authors.affiliation: Department of Biotechnology, Hankyong National University, 327 Chungang-no, Anseong, Gyeonggi-do, Republic of Korea.
authors.forename: Wan-Taek
authors.initials: WT
authors.lastname: Im
authors.affiliation: Department of Environmental Engineering, Hanbat National University, San 16-1, Duckmyoung-dong, Yuseong-gu, Daejeon, Republic of Korea.
authors.forename: Sae-Eun
authors.initials: SE
authors.lastname: Oh
authors.affiliation: School of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Pohang, Gyeongbuk, Republic of Korea. Electronic address: candlit@postech.ac.kr.
authors.forename: Seung Gu
authors.initials: SG
authors.lastname: Shin
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria; D019149:Bioreactors; D008697:Methane; D012722:Sewage; D014465:Ultrasonics
chemical_list: D012722:Sewage; D008697:Methane
keywords: Evenness; Low-strength ultrasonication; Pyrosequencing; Syntrophism; Upflow anaerobic sludge blanket; δ-Proteobacteria