Effect of thermophilic bacterial complex agents on synergistic humification of carbon and nitrogen during lignocellulose-rich kitchen waste composting.

Abstract

This work reported the effects of thermophilic bacterial agents on degrading persistent lignocellulose and reducing the loss of valuable nitrogen in kitchen waste (KW) composting. The results showed that thermophilic bacterial compound agents improved the high temperature period by 8 days, and increased the ligninase activity by 0.5-3 times during the composting process. The activity of cellulase increased up to 1 time in agent A (Geobacillus, Clostridium caenicola, Haloplasma) adding group by improving the microbial activity of lignocellulosic degradation metabolic pathways. Nitrogen storage increased to 70% in group added with agent B (Clostridium caenicola, Geobacillus, Clostridium sp. TG60-81) by increasing the population abundance of nitrogen-fixing microorganisms such as Bacillus, Hungateiclostridium and Herbaspirillum, and changed amino acid metabolic pathways. In general, agents A and B could increase the thermophilic phase, optimize the microbial community structure, realize the synergistic humification of carbon and nitrogen, and convert KW into mature and high quality fertilizers.