Improve spent mushroom substrate decomposition, bacterial community and mature compost quality by adding cellulase during composting

Three composting experiments were carried out to evaluate the effect of cellulase on the spent mushroom substrate (SMS) composting and develop a better disposal technology: added cellulase at the initial stage in T1, after the thermophilic stage in T2, while added no cellulase in the control experiments (CK). Results showed that cellulase accelerated SMS decomposition, improved bacterial community, promoted nitrate synthesis and improved mature compost quality. The total thermophilic stage of T2 reached 14 days, much longer than that of CK (8 days) and T1 (6 days). The cellulose degradation rate of T2 reached 41.22%, much higher than that of CK (19.86%) and T1 (29.72%). Total nutrient of mature compost increased by 13.13% in T2 and 3.28% in T1, compared with that of CK, respectively. Also, cellulase increased the humus content and the seed germination index (GI) of mature compost and decreased the electrical conductivity (EC) and the C/N ratio. The optimised cellulase adding time was after the thermophilic stage of composting. This study elucidated the role of cellulase in SMS composting, and provided an efficient disposal way for this organic residue, which was helpful for the cleaner production and sustainability of edible fungi industry. ? 2021 Elsevier Ltd. All rights reserved.

Automated summary

This study demonstrates that adding cellulase during spent mushroom substrate composting can accelerate decomposition, improve compost quality, and promote nitrate synthesis. The optimal time for adding cellulase is after the thermophilic stage of composting.