Effect of different moisture contents on hydrogen sulfide malodorous gas emission during composting.

[Display omitted] • Identified the role of low moisture content on H 2 S emission. • The KEGG pathway of H 2 S production by sulfate reduction was constructed. • The reduction of sulfate-reducing gene abundance weakened the sulfate reduction. • Change in the abundance of functional microorganisms was key to reduce H 2 S emission. The sulfate reduction reaction releases malodorous gases (H 2 S) during composting, with potential pollution risks to the environment. In this study, chicken manure (CM) with high sulfur content and beef cattle manure (BM) with low sulfur content were used to investigate the effect of control (CK) and low moisture content (LW) on sulfur metabolism. The results showed that compared to CK composting, the cumulative H 2 S emission of CM and BM composting decreased by 27.27% and 21.08% under LW condition, respectively. Meanwhile, the abundance of core microorganisms related to sulfur components was reduced under LW condition. Furthermore, the KEGG sulfur pathway and network analysis suggested that LW composting weakened the sulfate reduction pathway, and reduced the number and abundance of functional microorganisms and genes. These results indicated that low moisture content had important effects on inhibiting the release of H 2 S during composting, which provided a scientific basis to control environmental pollution. [ABSTRACT FROM AUTHOR]