Enrichment Culture of Methane-Oxidizing Bacteria and Acclimatization Experiment Research under Coal Mine Environmental Stress Mechanisms

The coal mining process causes large amounts of gas to be released into the atmosphere, which contributes to environmental pollution and the greenhouse effect. The use of microbial technology to oxidize and decompose mine gas can help reduce coal mine gas emissions and eliminate the threat of gas disasters. This study screened and enriched methane-oxidizing bacteria from typical coal mine soils in Guizhou, China, and analyzed the community structure, cell morphology, and methane degradation ability. A self-developed coal mine environment simulation experimental device was used to domesticate the methane-oxidizing bacteria so that they could be better adapted to the underground conditions of coal mines and maintain an efficient methane degradation rate. The experimental results showed that the growth of the enriched cultured methane-oxidizing bacteria went through delayed, logarithmic, stable, and decaying phases sequentially. According to the distribution of abundance from high to low, the methane-oxidizing bacteria were Pseudomonas, Methylobacter, Methylovulum, and Methylomicrobium, and the methane-oxidizing bacteria obtained after domestication in the coal mine environment not only maintained good stability, but also achieved a methane degradation rate of 72.71% within 96 h. The results also demonstrated that glucose could be used as a methane-oxidizing agent in the production of methane-oxidizing bacteria in coal mines. Meanwhile, it was verified that glucose could be used as a carbon source for the methane-oxidizing bacteria during the transportation process, which promotes the transformation of microbial degradation of gas management technology to engineering applications.