A novel enzyme-based strategy for improving compost quality using extracts from spent mushroom substrate

Hydrolases and oxidoreductases extracted from spent mushroom substrate (SMS) show potential as a strategy to improve compost quality, however, limited information is available. This research evaluated the influence of SMS endogenous enzymes on compost characteristics and explored the underlying mechanisms involved. The addition of SMS endogenous enzymes greatly improved the safety and maturity of compost products. Moreover, enzyme application led to increased microbial diversity and promoted the synergistic interactions between bacterial and fungal communities. The enhanced abundance of functional microorganisms including Cellulosimicrobium, Parapedobacter, unclassified_f_Bacillaceae, Bacillus, Trichoderma, Aspergillus and Kernia contributed to the improvement of organic matter degradation and compost humification. Carbohydrate and amino acid metabolisms driven by microorganisms were involved in the compost putrefaction process. Saprotroph was the dominant trophic mode of fungal community across all treatments. These findings confirm the effectiveness of SMS endogenous enzymes in accelerating compost maturation and propose a new strategy for promoting the utilization of solid waste composting.