Enhancing thermophilic composting through key thermophilic fungi: A microbial succession study

Abstract

Thermophilic microorganisms offer a favorable solution to accelerate thermophilic composting; however, the details of the microbial community responsible for compost production have only emerged recently. In this study, we reported a detailed study of fungal succession during thermophilic composting and identified key thermophilic fungi capable of enhancing the biological process of compost humification. Through high-throughput sequencing, a total of 238 fungal species were identified with β-diversity of the fungal community significantly changing during the thermophilic phase and then maintained a relatively stable composition. The Class of Eurotiomycetes played an important role in the Thermophilic and Maturation process and became the center of fungal community network. Functional prediction revealed that fungal groups with cellulose/xylan-degrading activities were significantly more abundant during the thermophilic phase compared to the initial stage. Subsequently, a total of 16 fungi were isolated in situ, and their phylogeny and degradation capabilities were determined. Two fungal strains were reintroduced into the compost, resulting in a shortened composting time from 5 days to 3 days, an improved germination index, and enhanced compost quality, particularly promoting wheat growth. The findings of this study contribute to the development of fungal inocula for accelerating composting and providing new strategies for the efficient utilization of agricultural waste. This research holds significant importance for the increasing utilization of agricultural waste.