First-Time Demonstration of a Two-Step Mechanism for Azo Dye Removal by Bacillus proteolyticus Using Molecular
Safiye Elif Korcan1, Nevin Çankaya1, Serap Yalçın Azarkan2
1Vocational School of Health Services, Usak University, Usak, Turkey.
Summary
Bacillus proteolyticus effectively removes azo dyes through biosorption and enzymatic degradation, with efficiency varying by dye structure. This research reveals a two-stage mechanism crucial for textile wastewater bioremediation.
Area of Science:
- Environmental microbiology
- Bioremediation
- Industrial biotechnology
Background:
- Azo dyes are persistent industrial pollutants resistant to biodegradation.
- Effective bioremediation strategies are needed to address textile wastewater contamination.
Purpose of the Study:
- To investigate the azo dye removal mechanism by Bacillus proteolyticus.
- To elucidate the role of bacterial enzymes and dye structure in biodegradation.
Main Methods:
- Microbiological assays and 16S rRNA gene sequencing for bacterial identification.
- FT-IR spectroscopy, molecular docking, and molecular dynamics simulations for mechanistic insights.
- Decolorization experiments with Acid Red 88 and Acid Blue 193.
Main Results:
- Bacillus proteolyticus OA7 showed higher removal efficiency for Acid Red 88 (69.74%) than Acid Blue 193 (41.01%).
- Acid Red 88 removal involved biosorption and biodegradation; Acid Blue 193 was mainly biosorbed.
- FT-IR indicated changes in functional groups and azo bond transformation; molecular docking identified key redox enzymes involved in degradation.
Conclusions:
- A two-stage mechanism of biosorption followed by enzymatic redox-mediated degradation was proposed.
- Bacterial response and dye removal efficiency are influenced by azo dye structure.
- This study offers mechanistic insights into Bacillus proteolyticus-mediated azo dye bioremediation.
