Synthetic microbial community enhances lignocellulose degradation during composting by assembling fungal communities.

Inoculating synthetic microbial community (SynCom) has been proposed as an eco-friendly approach for lignocellulose degradation in composting to enhance organic fertilizer quality. However, the mechanisms responsible for SynCom-regulated lignocellulose degradation during composting remain unclear. Here the SynCom inoculation decreased cellulose and hemicellulose contents by 26.2% and 14.3%, respectively, at the mature phase, while increasing endoglucanase, exoglucanase, and β-glucosidase activities significantly. SynCom inoculation increased the abundance of Cephaliophoras and Thermomyces at the mesophilic phase, Sordariomycetes at the thermophilic phase, and Thermomyces, Acremonium, Aspergillus, and Sordariomycetes at the mature phase, as well as increased the abundance of numerous Operational Taxonomic Units (OTUs), with OTU10 (Hydropisphaera) being responsible for lignocellulose degradation. The altered fungal community stimulated functions of the wood saprotroph, undefined saprotroph, and litter saprotroph were responsible for lignocellulose degradation via changing microbial community. The results suggest that SynCom inoculation effectively stimulate lignocellulose degradation, so that benefits quality improvement of organic fertilizer.