title: Experimental evaluation of the metabolic reversibility of ANME-2d between anaerobic methane oxidation and methanogenesis.
abstract: The "reverse methanogenesis" hypothesis as the metabolic pathway of AOM has recently been supported in the novel ANME lineage ANME-2d in denitrifying anaerobic methane oxidation (DAMO). However, no previous studies have experimentally evaluated the reversal of methane oxidation and methane production in this archaea. In the present study, the metabolic reversibility of ANME-2d from AOM to methanogenesis was evaluated using H2/CO2 and acetate as substrates. The results showed that the system produced methane from H2/CO2 but not from acetate. However, the clone library and real-time PCR analysis of the culture showed that both the percentage and quantity of ANME-2d decreased significantly under this condition, while methanogen abundance increased. Further high-throughput sequencing results showed that the archaea community did not change at the fourth day after H2/CO2 was supplied, but changed profoundly after methanogenesis took place for 3 days. The percentage of DAMO archaea in the total archaea decreased obviously, while more methanogens grew up during this period. Comparatively, the bacteria community changed profoundly at the fourth day. These results indicated that ANME-2d might not reverse its metabolism to produce methane from H2/CO2 or acetate. After archaea were returned to DAMO conditions, DAMO activity decreased and the amount of ANME-2d continued to fall, implying that the lineage had suffered from severe injury and required a long recovery time.
authors.affiliation: Advanced Laboratory for Environmental Research and Technology, USTC-CityU, Suzhou, 215123, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Ding
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Fu
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, People's Republic of China.
authors.forename: Zhao-Wei
authors.initials: ZW
authors.lastname: Ding
authors.affiliation: CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, People's Republic of China.
authors.forename: Yong-Ze
authors.initials: YZ
authors.lastname: Lu
authors.affiliation: Advanced Laboratory for Environmental Research and Technology, USTC-CityU, Suzhou, 215123, People's Republic of China.|State Key Laboratory in Marine Pollution, Department of Biomedical Science, City University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Shuk H
authors.initials: SH
authors.lastname: Cheng
authors.affiliation: Advanced Laboratory for Environmental Research and Technology, USTC-CityU, Suzhou, 215123, People's Republic of China. rzeng@ustc.edu.cn.|CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China, Hefei, 230026, People's Republic of China. rzeng@ustc.edu.cn.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Zeng
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000145:classification* / Q000378:metabolism; D001419:Bacteria / Q000145:classification; D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D058440:Denitrification; D008697:Methane / Q000378:metabolism*; D010084:Oxidation-Reduction; D010802:Phylogeny; D019642:RNA, Archaeal / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D019642:RNA, Archaeal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D008697:Methane
keywords: ANME-2d; DAMO; Metabolic reversibility; Methanogenesis; “Reverse methanogenesis” hypothesis