Taxonomic identification, genomic analysis, and optimized chromium(VI) bioreduction by <i>Microbacterium triticisoli</i> sp. nov. M28 ^T

Strain M28^T was isolated from subsoil obtained from decaying wheat straw. Cells were Gram-positive, non-motile, short rod-shaped and formed yellowish colonies on lysogeny broth (LB) agar. The strain was able to grow at 0-8% (w/v) NaCl , 15-40 °C and pH 5.5-10.0. Phylogenetic analysis based on 16S rRNA gene sequences, core genes and whole-genome indicated that strain M28^T belonged to the genus <i>Microbacterium</i> but was distinct from all known strains in this genus. Based on phenotypic, genotypic, chemical taxono mic and phylogenetic analyses, strain M28^T is a representative of a new species of <i>Microbacterium</i>, which is proposed to be named <i>Microbacterium triticisoli</i> sp. nov., the type strain is M28^T (=CCTCC AA 2022021^T =JCM 35796^T). Genomic analysis revealed multiple metal resistance systems, antibiotic resistance determinants and oxidative stress defense genes, explaining its exceptional environmental adaptability. Notably, the strain reduced 99% of 50 mg/L Cr(VI) within 24 h under optimized conditions (37 °C, pH 7.0, 2.5 g/L sucrose) and tolerated Cr(VI) concentrations up to 125 mg/L. This study identifies <i>M. triticisoli</i> as a promising agent for chromium bioremediation, providing a foundation for engineering microbial solutions to heavy metal pollution.