A mechanism of microbial sensitivity regulation on interventional remediation by nanozyme manganese oxide in soil heavy metal pollution

Studies have found that nanozyme materials can be an potential solution for microorganisms with insufficient enzyme activities to meet habitat requirements, bringing new application prospects for the remediation of soil pollution via inoculation with exogenous microorganisms. However, few studies have investigated the mechanism of microbial sensitivity regulation when using nanozyme materials. In this study, we attempt to fill this gap by investigating the microbial sensitivity regulation mechanism (MSRM) on typical paddy field heavy metal pollution (As3+ and Cr6+) using nanozyme nanoMn3O4-coated microbial populations (NMCMP). Analysis of maintained enzyme activity, changes in microbial community structure and heavy metal content showed that the sensitivity of microbial community composition can be significantly altered by adding nanoMn3O4-coated microbial communities via 16s DNA and metagenomic analyses. Flavisolibacter and Arthrobacter were confirmed as two main bacteria species relevant to the remediation of the heavy metal pollution (As3+ and Cr6+). In addition, we also found that NMCMP could enhance the reduction of Cr6+ level and inhibit the release and rapid oxidation of As3+ from As2H2S3 during the process of remediation. This study will provide important research value for the remediation of soil heavy metal pollution by microbial methods.