Effects of exogenous thermophilic bacteria and ripening agent on greenhouse gas emissions, enzyme activity and microbial community during straw composting.

This research examined the impact of exogenous thermophilic bacteria and ripening agents on greenhouse gas (GHG) emission, enzyme activity, and microbial community during composting. The use of ripening agents alone resulted in a 30.9 % reduction in CO emissions, while the use of ripening agents and thermophilic bacteria resulted in a 50.8 % reduction in NO emissions. Pearson's analysis showed that organic matter and nitrate nitrogen were the key parameters affecting GHG emissions. There was an inverse correlation between CO and CH releases and methane monooxygenase α subunit and NO reductase activity (P<0.05). Additionally, NO emissions were positively related to β-1, 4-N-acetylglucosaminidase, and ammonia monooxygenase activity (P<0.05). Deinococcota, Chloroflexi, and Bacteroidota are closely related to CO and NO emissions. Overall, adding thermophilic bacteria represents an effective strategy to mitigate GHG emissions during composting.