<p>This study isolated and characterized a novel manganese-oxidizing bacterium from soil near a manganese mine in Zunyi, Guizhou. The strain was isolated using gradient dilution and quadrant streaking methods, followed by preliminary screening via the leucoberbelin blue I (LBB) colorimetric assay to detect high-valent manganese oxides. Gram staining and 16&#xa0;S rRNA gene sequencing identified the isolate as <i>Pseudochrobactrum saccharolyticum</i>, a Gram-negative short rod-shaped bacterium. This is the first report of its ability to oxidize manganese. Single-factor experiments were conducted to optimize environmental conditions affecting bacterial growth and Mn oxidation efficiency, including initial pH (4.0–8.0), temperature (18–38 ℃), Mn²⁺ concentration (1–20 mmol/L), and the presence of coexisting metal ions (Fe³⁺, Cu²⁺, Ca²⁺; 10–80 µmol/L). The optimal conditions for Mn²⁺ removal and biogenic manganese oxide (BMO) production were determined as follows: temperature 33 ℃, initial pH 6.0, Mn²⁺ concentration 5 mmol/L, and Supplementation with 20 µmol/L Fe³⁺. Under these conditions, the Mn²⁺ removal rate reached 92.05%, and BMO production was 3.55 mmol/L. Among the coexisting metals, Fe³⁺ markedly enhanced bacterial growth and Mn-oxidizing activity. In contrast, Cu²⁺ and Ca²⁺ showed dual effects: low concentrations inhibited manganese oxide formation, whereas higher concentrations promoted it. The resulting BMOs were characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). XPS analysis revealed that the BMOs consisted mainly of Mn⁴⁺ (69.30%), with minor proportions of Mn³⁺ (19.92%) and Mn²⁺ (10.78%). FTIR spectra confirmed the presence of hydroxyl (-OH), amide (-CONH-), and methyl (-CH₃) functional groups, which are conducive to Mn²⁺ adsorption and oxidation. This study demonstrates that <i>Pseudochrobactrum saccharolyticum</i> possesses efficient manganese-oxidizing capacity, enriching the diversity of known Mn-oxidizing bacteria and offering a promising indigenous candidate and theoretical foundation for bioremediating Mn pollution in karst manganese-mining regions.</p>