Heavy metal tolerance and detoxification mechanism mediated by heavy metal resistance genes in compost habitat

Heavy metal pollution from compost is one of the most concerned environmental problems, which poses a threat to the ecosystem and human health. This study aims to reveal the heavy metal tolerance and detoxification mechanism mediated by heavy metal resistance genes (HMRGs) in compost habitat through metagenomics combined with chemical speciation analysis of heavy metals. The results showed that there were 37 HMRGs corresponding to 7 common heavy metal(loid)s in composting, and they had the ability to transform heavy metals into stable or low-toxic speciation by regulating enzyme transport, redox, methylation, etc. This study summarized the heavy metal metabolism pathway mediated by HMRGs, providing a new perspective for understanding the transformation of heavy metals in the composting process.