Amino-functionalized hydrogel immobilized microbial consortia to reduce the dissemination risks of antibiotic resistance genes in soil.

Antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) have posed an environmental threat to soil due to the excessive utilization of antibiotics. Traditional material-biological remediation strategies were limited by the difficulty of colonizing functional bacteria and insufficient removal efficiency of ARB and ARGs. Here, a functionalized carboxymethyl chitosan hydrogel with functional microbial consortia (NCMC + mc) remediation strategy was employed to reduce the dissemination risks of ARGs in soil and improve soil health. The NCMC + mc treatment reduced the levels of targeted ARGs in soil by 58.05 %-94.24 %. The crop cultivation and earthworm breeding experiments conducted in the restored soil demonstrated the effectiveness of NCMC + mc in reducing the spread of ARGs. The targeted ARGs in crops were reduced by 77.17 %-90.80 %, and those in earthworms by 52.13 %-94.71 %. Random Forest analysis predicted that Acidimicrobia was the main host or spreading bacteria for ARGs. The effectiveness of NCMC + mc system was further confirmed by TOPSIS evaluation model. This study provides an effective remediation strategy for reducing the dissemination of ARGs to improve soil health.