Arabian Journal of Chemistry (Sep 2022)
Mixed dye degradation by Bacillus pseudomycoides and Acinetobacter haemolyticus isolated from industrial effluents: A combined affirmation with wetlab and in silico studies
Abstract
The environment-friendly bacterial strains are used for wastewater treatment due to their high degrading capability and cost-effectiveness. In the present study, we isolated, identified, characterized, and optimized culture condition ( Temperature 35 °C for both, time up to 96 h, pH 7 and 7.5 respectively) of two dye degrading bacteria from industrial effluents. Morphological, biochemical, and molecular identification confirmed those strains as Bacillus pseudomycoides and Acinetobacter haemolyticus. Spectrophotometric methods were used to investigate the dye degradation(single and mixed dye) capability of these two bacteria. These strains were the potential for degrading methylene green (MG), basic violet (BV) and acid blue (AB) dyes. In case of MG + BV, B. pseudomycoides, and A. haemolyticus showed a degradation rate of 74% and 75%, respectively. While degradation was found 75% and 82% for MG + AB combination, 73% and 73% for AB + BV combination, and 80% and 82% for MG + BV + AB combination respectively. Azoreductase enzymes from bacteria are essential for breaking down the azo bond in textile azo dyes. In molecular docking, the binding energy of three docking complexes (protein and MG, protein and BV, protein and AB) were −6.3, −6.6, and −6.8 Kcal/mol, respectively. The binding stability of the docked complexes was ensured by the root mean square deviations (RMSD), solvent accessible surface area (SASA), radius of gyration (Rg) and hydrogen bond in a molecular dynamics simulation study, indicating strong and stable binding. This study revealed that both B. pseudomycoides and A. haemolyticus could decolorize single and mixed dyes efficiently. As a result, both the strains could be used in further research to apply their potentiality in large-scale dye degradation in the future.
