Marine Enterobacter roggenkampii-Driven Bio-electrochemical Mineralization of Benzothiazole

Benzothiazole (BZT), a persistent heterocyclic contaminant commonly leached from microplastic debris, poses a significant ecological hazard due to its chemical recalcitrance and toxicity. This study presents the first comprehensive investigation of BZT bio-electrochemical degradation, leveraging synergistic interactions between microbial metabolism and electrochemical stimulation for sustainable remediation. A novel BZT-degrading bacterium, Enterobacter roggenkampii , was isolated from marine environment and incorporated into a bio-electrochemical system (BES). Process parameters including initial BZT concentration (150 mg/L), pH (8), inoculum dose (1% v/v), and applied potential (1.5 V) were systematically optimized, achieving a maximum degradation efficiency of 98.54% under these optimized conditions. Enzyme activity assays revealed markedly enhanced esterase, dehydrogenase, peroxidase, and catechol 1,2-dioxygenase activities in BES treatments compared to biodegradation, supporting synergistic microbe electrode interactions. HPLC–MS/MS analysis identified transient intermediates and enabled the elucidation of a complete BZT degradation pathway involving hydroxylation, aromatic ring cleavage, and subsequent mineralization to non-toxic end products. Ecotoxicological evaluation using Eisenia fetida demonstrated pronounced reductions in mortality, growth inhibition, and oxidative stress biomarkers in BES-treated effluents, validating effective detoxification. Overall, this work establishes bio-electrochemical degradation as a potent, eco-friendly, and scalable strategy for eliminating BZT and other microplastic-associated micropollutants from aquatic environments.