Bisphenol A (BPA) is a widespread pollutant threatening the ecosystem and human health. An effective BPA degrader YC-JY1 was isolated and identified as Sphingobium sp. The optimal temperature and pH for the degradation of BPA by strain YC-JY1 were 30 °C and 6.5, respectively. The biodegradation pathway was proposed based on the identification of the metabolites. The addition of cytochrome P450 (CYP) inhibitor 1-aminobenzotriazole significantly decreased the degradation of BPA by Sphingobium sp. YC-JY1. Escherichia coli BL21 (DE3) cells harboring pET28a-bisdAB achieved the ability to degrade BPA. The bisdB gene knockout strain YC-JY1ΔbisdB was unable to degrade BPA indicating that P450bisdB was an essential initiator of BPA metabolism in strain YC-JY1. For BPA polluted soil remediation, strain YC-JY1 considerably stimulated biodegradation of BPA associated with the soil microbial community. These results point out that strain YC-JY1 is a promising microbe for BPA removal and possesses great application potential.

Di-(2-ethylhexyl) phthalate (DEHP) is one of the phthalic acid ester representatives and is mainly used as a plasticizer to endow polyvinyl chloride plastics with desirable physical properties. It is synthesized in massive amounts worldwide. Many studies have proved the adverse effects of DEHP on human health and wildlife. DEHP is labeled as an endocrine disruptor which causes human reproductive problems. Enterobacter spp. YC-IL1, a novel isolated strain from contaminated soil, was identified by 16S rRNA gene analysis and electronic microscope. It is capable of efficiently degrading DEHP (100%) and a wide range of phthalic acid ester PAEs, particularly those containing side chains with branches, or ring structures such as dutylbenzyl phthalate and dicyclohexyl phthalate, which are hard to degrade, with, respectively, 81.15% and 50.69% degradation after 7 days incubation. YC-IL1 is an acido-tolerant strain which remained in pH values lower than pH 5.0 with the optimum pH 7.0 and temperature 30 °C. The DEHP metabolites were detected using HPLC-QQQ and then the degradation pathway was tentatively proposed. Strain YC-IL1 showed high DEHP degradation rate in artificially contaminated soil with 86% removed in 6 days. These results indicate the application potential of YC-IL1 in bioremediation of PAE-polluted sites, even the acidic ones.

Background Bisphenol A (BPA) is a rapid spreading organic pollutant that widely used in many industries especially as a plasticizer in polycarbonate plastic and epoxy resins. BPA reported as a prominent endocrine disruptor compound that possesses estrogenic activity and fulminant toxicity. Pseudomonas putida YC-AE1 was isolated in our previous study and exerted a strong degradation capacity toward BPA at high concentrations; however, the molecular degradation mechanism is still enigmatic. Results We employed RNA sequencing to analyze the differentially expressed genes (DEGs) in the YC-AE1 strain upon BPA induction. Out of 1229 differentially expressed genes, 725 genes were positively regulated, and 504 genes were down-regulated. The pathways of microbial metabolism in diverse environments were significantly enriched among DEGs based on KEGG enrichment analysis. qRT-PCR confirm the involvement of BPA degradation relevant genes in accordance with RNA Seq data. The degradation pathway of BPA in YC-AE1 was proposed with specific enzymes and encoded genes. The role of cytochrome P450 (CYP450) in BPA degradation was further verified. Sever decrease in BPA degradation was recorded by YC-AE1 in the presence of CYP450 inhibitor. Subsequently, CYP450bisdB deficient YC-AE1 strain △ bisdB lost its ability toward BPA transformation comparing with the wild type. Furthermore, Transformation of E. coli with pET-32a-bisdAB empowers it to degrade 66 mg l−1 of BPA after 24 h. Altogether, the results showed the role of CYP450 in biodegradation of BPA by YC-AE1. Conclusion In this study we propose the molecular basis and the potential role of YC-AE1cytochrome P450 monooxygenase in BPA catabolism.