Transcriptome analysis and cytochrome P450 monooxygenase reveal the molecular mechanism of Bisphenol A degradation by Pseudomonas putida strain YC-AE1

Abstract

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.

Detection of the cytochrome C gene in bisphenol A-degrading Bacteria isolated from contaminated soil in some areas of Karbala Province, Iraq

“…According to Sasaki et al, expressing the bisdAB genes in various strains of E. coli grown on BPA-containing medium increased the degradation activity of BPA, from 10 mg/L to 30-90 mg/L within 18 hours; these engineered strain of E. coli exclusively converted BPA into 1,2-bis,4hydroxyphenyl-2-propanol (byproduct1), a cytochrome P450 monooxygenase activity product; additionally, another product of BPA degradation by these modified cells was detected as byproduct II, which was not previously observed in degradation pathway of BPA in these strains [26]. The proposed degradation pathway of BPA outlined specific enzymes as well as, encoded genes; further verification solidified the cytochrome C P450 (CYP450) role, in degradation of BPA; a notable reduction in BPA degradation was observed in the presence of a CYP450 inhibitor; subsequently, a CYP450 bisdAB-deficient strain exhibited a loss in its ability to transform BPA compared to the wild type strain; moreover, introducing bisdAB into E. coli enabled the degradation of 66 mg/L of BPA within 24 hours; these findings underscore the importance of CYP450 in the BPA biodegradation [25].…”

“…The bisdAB operon from Sphingomonas spp. was cloned into the bacteria E. gergoviae, and the impact of its expression and degradation activity of BPA had been investigated; so, strains carrying the bisdAB operon were successfully isolated on media with 25 µg/mL BPA as the only carbon source, confirming the presence of the bisdAB operon and its role in BPA degradation activity [25]. According to Sasaki et al, expressing the bisdAB genes in various strains of E. coli grown on BPA-containing medium increased the degradation activity of BPA, from 10 mg/L to 30-90 mg/L within 18 hours; these engineered strain of E. coli exclusively converted BPA into 1,2-bis,4hydroxyphenyl-2-propanol (byproduct1), a cytochrome P450 monooxygenase activity product; additionally, another product of BPA degradation by these modified cells was detected as byproduct II, which was not previously observed in degradation pathway of BPA in these strains [26].…”

The Role of Biodegrading-bacteria to Remove Bisphenol-A from Polluted Soils

“…was known to inhabit diverse habitats such as soil, activated sludge, forests, compost, fecal matter, lakes and various food sources; additionally, these bacterial species had been documented to exhibit potential in the biodegradation of various pollutants, including plastic mixture wastes [19]. Prior researches had demonstrated that, bacteria such as Sphingobium sp., Pseudomonas putida, Bacillus megaterium, Arthrobacter sp., and Achromobacter xylosoxidans exhibited the capacity to degrade BPA effectively [20,21].…”