Efficient synergistic accomplishment of methyl orange decolorization and Cr(VI) adsorption by Staphylococcus succinus H3.

AIMS: Dye‑Cr(VI) co‑pollution poses serious environmental hazards; endophytic bacteria are promising bioremediators while their dual pollutant removal traits remain insufficiently explored. This work evaluated Staphylococcus succinus H3 for synchronous MO decolorization and Cr(VI) removal, as well as its detoxification performance.

METHODS AND

RESULTS

Experiments included co-contaminant treatment, MO-only metabolomics, phytotoxicity assay, and Cr(VI) removal mechanism characterization of S. succinus H3. In co-contaminated systems, S. succinus H3 achieved 45% MO decolorization via azoreductase-mediated reductive cleavage of azo bonds, producing sulfanilic acid and N, N-dimethylaniline. Under MO stress, adaptive responses including oxidative stress, fatty acid oxidation and biofilm formation were observed. Cr(VI) biosorption (60%) mainly relied on cell surface interactions with proteins, polysaccharides and lipids. MO metabolites significantly reduced phytotoxicity (p < 0.05), promoting seed germination, root elongation and biomass accumulation in wheat and rapeseed.

CONCLUSIONS

Staphylococcus succinus H3 exhibits strong potential for bioremediation of complex industrial wastewater with azo dyes and heavy metals.