Effects of functional-membrane covering technique on nitrogen succession during aerobic composting: Metabolic pathways, functional enzymes, and functional genes

This study investigated and assessed the effect of the functional-membrane covering technique (FMCT) on nitrogen succession during aerobic composting. By comparative experiments involving high-throughput sequencing and qPCR, nitrogen metabolism (including the ko00910 pathway and functional enzyme and gene abundances) was analyzed, and the nitrogen succession mechanism was identified. The FMCT created a micropositive pressure, improved the aerobic conditions, and increased the oxygen utilization rate and temperature. This strongly affected the nitrogen metabolism pathway and down-regulated the nitrifying and denitrifying bacteria abundances. The FMCT up-regulated the relative abundance of glutamate dehydrogenase and downregulated the absolute abundances of AOB and nxrA. This and the high temperature increased NH3 emissions by 13.78%-73.37%. The FMCT down-regulated the abundances of denitrifying gene groups (nirS + nirK)/nosZ and nitric oxide reductase associated with N2O emissions and decreased N2O emissions by 16.44%-41.15%. The results improve the understanding of the mechanism involved in nitrogen succession using the FMCT.

Automated summary

This study investigated the effect of the functional-membrane covering technique on nitrogen succession during aerobic composting. The results showed that the technique improved the aerobic conditions, affected the nitrogen metabolism pathway, and reduced emissions of nitric oxide and ammonia.