Characterization and production of a Bacillus mycoides Bioflocculant for sustainable effluent treatment

Industrial effluent treatment relies on chemical coagulants, which incur higher costs and generate toxic sludge. This study isolated and identified bioflocculant-producing Bacillus mycoides (S39) strain and enhanced yield using one-factor-at-a-time optimization. Characterization studies of purified bioflocculant reveal a crystalline polysaccharide bearing amine, hydroxyl, and carboxylate groups that drive adsorption and polymer bridging. The bioflocculant exhibited flocculation activities of 95.56 % for textile effluent and 92.84 % for steel wastewater with Ca²⁺ activation. Bioflocculant remained stable across pH and temperature. Kinetics followed a pseudo-first-order model, yielding rate constants, an optimized dosage, and assistance with sizing. Hemolysis (<5 %) and viability (>80 %) assays indicated non-cytotoxicity. The bioflocculant maintained performance ranged from 0.01 to 10 L, supporting S39 as a sustainable alternative to chemical coagulants. This study investigated the potential of B. mycoides bioflocculant, which showed promise as a sustainable and high-efficiency alternative to conventional coagulants and, to the best of our knowledge, the first kinetic and scale-relevant evaluation of this strain for wastewater treatment.