Isolation and screening of bacteria capable of oxidizing methane - causing greenhouse effect

In recent years, methane concentration has increased rapidly due to agricultural production activities, in which livestock production is a significant source of methane emissions. Methane is the second-largest carbon compound in the atmosphere and 25 times more radiatively effective than carbon dioxide which is the main reason for ozone depletion. In this study, strains of bacteria capable of oxidizing methane (Methane Oxidizing Bacteria - MOB) were isolated and screened. From 13 samples of mud soil, 32 samples of rice land, 04 samples of biogas wastewater, 03 samples of the rumen, and 04 samples of river water, we isolated 370 bacterial strains capable of reducing CH4 on dAMS medium with CH4 being the sole carbon source. Quantitative results show that 19 bacterial strains can reduce CH4 including two strains TB18 and DC11 isolated from rice soil and rumen have the highest ability to oxidize methane (32.6 ± 0.25%, 30.2 ± 0.14%). The results of this study are the premise for the application of MOB bacteria in order to produce microbial products so that CH4 emissions can be reduced in Vietnam’s agriculture and raising cattle.