Community succession of microbial populations related to CNPS biological transformations regulates product maturity during cow-manure-driven composting.

The main objective of present study was to understand the community succession of microbial populations related to carbon-nitrogen-phosphorus-sulfur (CNPS) biogeochemical cycles during cow-manure-driven composting and their correlation with product maturity. The abundance of microbial populations associated with C degradation, nitrification, cellular-P transport, inorganic-P dissolution, and organic-P mineralization decreased gradually with composting but increased at the maturation phase. The abundance of populations related to N-fixation, nitrate-reduction, and ammonification increased during the mesophilic stage and decreased during the thermophilic and maturation stages. The abundance of populations related to C fixation and denitrification increased with composting; however, the latter tended to decrease at the maturation stage. Populations related to organic-P mineralization were the key manipulators regulating compost maturity, followed by those related to denitrification and nitrification; those populations were mediated by inorganic N and available P content. This study highlighted the consequence of microbe-driven P mineralization in improving composting efficiency and product quality.