[Acclimatization and characteristics of microbial community in sulphate-dependent anaerobic methane oxidation]

The greenhouse effect of methane is 26 times worse than that of carbon dioxide, and wastewater containing high concentrations of sulfate is harmful to water, soil and plants. Therefore, anaerobic oxidation of methane driven by sulfate is one of the effective ways for methane reduction. In this paper, with sulfate as the electron accepter, a microbial consortium capable of oxidating methane under anaerobic condition was cultured. The diversity and characteristics of bacterial and archaeal community were investigated by PCR-DGGE, and phylogenetic analysis of the dominant microorganisms was also carried out. The DGGE fingerprints showed that microbial community structure changed distinctly, and the abundance of methane-oxidizing archea and sulfate-reducing bacteria increased in the acclimatization system added sulfate. After acclimatization, the bacterial diversity increased, while archaea diversity decreased slightly. The representative bands in the DGGE profiles were excised and sequenced. Results indicated that the dominant species in the acclimatization system were Spirochaetes, Desulfuromonadales, Methanosarcinales, Methanosaeta. Methane converted into carbon dioxide while sulfate transformed into hydrogen sulfide and sulfur in the process of anaerobic methane oxidation accompanied by sulphate reduction.