Isolation and characterization of a bisphenol A-degrading strain, Pseudomonas aeruginosa DU2, from soil containing decaying plants

Bisphenol A (BPA) is a toxic compound with broad applications in the plastics industry. BPA has harmful effects on various organisms and its efficient removal is necessary. The microbial degradation of BPA is a safe and economical approach. In this research, soil samples containing decaying plants were screened to isolate a BPA-degradable bacterial strain. Soil samples were collected from different locations in Damghan, Semnan province, Iran. To enrich BPA-degrading bacteria, the samples were cultured in a stepwise manner in a mineral medium containing increasing BPA concentrations (5 to 40 mg/L). The ability of isolated bacteria in degrading BPA was assayed by Folin-Ciocalteu and high-performance liquid chromatography methods. The biodegradation efficiency of the most efficient isolate was assayed under distinct conditions and it was identified through the sequencing of the 16S rRNA gene. Among the isolated bacteria, DU2 (GenBank accession number: OP919484) showed the most BPA biodegradation ability. The highest BPA degradation (52.98%) was observed in the mineral medium containing 5 mg/L BPA and the inoculum size of 6 × 10 CFU/mL at pH 9 and in the presence of 0.05% (w/v) NaCl during 10 days. These results offer soil containing decaying plants as a promising source for finding BPA-degrading bacteria. DU2 has basal BPA removal ability, which could be improved by optimization of medium components and growth conditions.