“…Burkholderiales, Clostridiales, and Gaiellales are key orders in the deep bedrock biosphere, ,, and Neisseriales might originate from exogenous microbial sources and is thought to be associated with groundwater . In addition, some increased orders might be closely related to nitrogen metabolism, including Blastocatellales, Rhodocyclales, Nitrosomonadales, Deinococcales, and Micrococcales, which may be due to the increased soluble nitrogen in soil extractions. In parallel, exogenous soil_2 can also potentially affect the decomposition and methane production processes of coal seams.…”