Dimethyl Disulfide enhances soil manganese bioavailability by inhibiting biological oxidation at individual and community levels

Background: Fumigation can enhance the bioavailability of manganese in soil, with microorganisms playing a crucial role in its biogeochemical cycling. However, the microbiological mechanisms underlying changes in manganese bioavailability following fumigation remain unclear. This study employed 16S rRNA microbial quantification sequencing and transcriptome analysis, combined with AlphaFold3 protein structure prediction and molecular docking techniques, to elucidate the responses of manganese-oxidizing microorganisms to fumigation at both community and individual levels.Results: The experimental results showed that DMDS significantly altered the structure of the manganese-oxidizing microbial community in the soil. However, as the soil ecosystem recovered post-fumigation, both the microbial community structure and manganese bioavailability gradually returned to pre-fumigation levels. Additionally, DMDS was found to inhibit biofilm formation in Pseudomonas putida MnB1, a manganese-oxidizing model microorganism, disrupting its functional integrity. This inhibition also led to changes in the expression of key energy metabolism pathways, specifically oxidative phosphorylation and the TCA cycle. Notably, the gene MnxG, which is crucial for manganese oxidation in P. putida MnB1, showed a binding energy of -2.4 kcal/mol with DMDS, suggesting that DMDS forms hydrophobic interactions with the MnxG protein.Conclusions: Our findings highlight that fumigation enhances manganese bioavailability in soil by inhibiting its biological oxidation.