Cornstalks regulate bacterial dynamics to benefit organic humification in food waste digestate composting
Wanning Li, Xingzu Gao, Runze Fan, Jialei Gai, Guoxue Li, Wenhai Luo, Chuanren Qi, Zhicheng Xu
Abstract
This study investigated the effects of different ratios of cornstalks (0 %, 5 %, 7.5 %, and 10 %) on bacterial dynamics for organic humification in food waste digestate composting. Results showed that addition ratios of cornstalks above 7.5 % effectively enhanced organic degradation for humification via both biotic and abiotic processes during composting. Specifically, adding cornstalks could stimulate the proliferation of bacteria belonging to Firmicutes and Bacteroidetes for lignocellulosic degradation This stimulation enhanced hemicellulosic decomposition by above 49.0 %. Furthermore, addition of cornstalks also promoted the transformation of protein, reducing sugars, and polysaccharides to elevate humus content by 53.23 % by the conclusion of composting. Notably, compared to the other ratios, 7.5 % of cornstalks exhibited the most excellent performance to improve organic biodegradation and compost humification given its capability to enrich more functional bacteria (e.g. Tepidimicrobium and Ureibacillus ). Results from this study provide valuable insights into performance enhancement in food waste digestate composting for contributing to the sustainable development of upstream anaerobic digestion. • Cornstalks improved organic degradation for humification in digestate composting. • Adding cornstalks enriched functional bacteria for lignocellulosic degradation. • Adding cornstalks promoted the transformation of organic matter to humus. • 7.5 % of cornstalks was more favorable to regulate organic humification in composting.