Hydrothermal pretreatment contributes to accelerate maturity during the composting of lignocellulosic solid wastes

[Display omitted] •Hydrothermal pretreatment coupled with aerobic fermentation (HTPAF) was established.•Lignin was well degraded in HTPAF process.•The humification cycle was shortened to 12 days in HTPAF.•Beneficial microorganisms but few pathogenic bacteria appeared in HTPAAF. The aim of this work was to study the optimal conditions and mechanism of lignocellulose degradation in the hydrothermal pretreatment coupled with aerobic fermentation (HTPAF). The optimized process parameters in the hydrothermal pretreatment (HTP) were discussed. The response relationship between enzyme activity and microbial community in HTPAF were explored. The results showed that with the moisture content of 50%-90%, the lignin content decreased by 150 mg/g after treatment at 120 °C for 6 h, and a loose pore structure was formed on the surface of the chestnut shells after HTP. The compost maturity time was shortened to 12 days. The dominant microbial genera in HTPAF were Gallicola, Moheibacter and Atopostipes, which were significant different with that of the traditional composting. HTPAF is beneficial to increase the maximum temperature of aerobic fermentation and quickly degrade lignin to shorten the maturity time.