Exploring the potential of the halotolerant bacterial strain Bacillus subtilis LN8B as an ecofriendly sulfide collector for seawater flotation.

This article evaluates the effectiveness of the halotolerant bacterium *Bacillus subtilis* strain LN8B as a biocollector for recovering pyrite (Py) and chalcopyrite (CPy) in both seawater (Sw) and deionized water (Dw) through bioflotation. The study found that *B. subtilis* LN8B significantly enhances mineral recovery—up to 72.8% for Py and 84.6% for CPy in Sw—by increasing mineral surface hydrophobicity via protein-mediated adsorption, as confirmed by zeta potential and Fourier-transform infrared spectroscopy analyses. The strain demonstrated robust growth in varying salinities and water types, and antibiotic susceptibility tests indicated minimal environmental risk. These findings suggest that *B. subtilis* LN8B is a promising ecofriendly alternative to conventional toxic collectors for sulfide mineral flotation, supporting cleaner mineral processing and potential acid mine drainage prevention.