Triphenyltin biodegradation and intracellular material release by Brevibacillus brevis

• Triphenyltin, diphenyltin and monophenyltin were degraded by Brevibacillus brevis.
• Metabolites, ion and protein release, membrane permeability, viability were detected.
• Triphenyltin could be degraded simultaneously to diphenyltin and monophenyltin.
• Triphenyltin increased Cl−, Na+, Ca2+ and protein release, and membrane permeability.
• B. brevis metabolically released Cl− and Na+, and passively diffused Ca2+.

Triphenyltin (TPT) is an endocrine disruptor that has polluted the global environment, and thus far, information regarding the mechanisms of TPT biodegradation and intracellular material release is limited. Here, TPT biodegradation was conducted by using Brevibacillus brevis. Degradation affecting factors, metabolite formation, ion and protein release, membrane permeability, and cell viability after degradation were investigated to reveal the biodegradation mechanisms. The results showed that TPT could be degraded simultaneously to diphenyltin and monophenyltin, with diphenyltin further degraded to monophenyltin, and ultimately to inorganic tin. During degradation process, B. brevis metabolically released Cl− and Na+, and passively diffused Ca2+. Protein release and membrane permeability were also enhanced by TPT exposure. pH ranging from 6.0 to 7.5 and relatively high biomass dosage in mineral salt medium improved TPT degradation. Biodegradation efficiency of 0.5 mg L−1 TPT by 0.3 g L−1B. brevis at 25 °C for 5 d was up to 80%.