Functionality, characterization and DEGs contribution by engineering isolate Pseudomonas P1 to elucidate the regulation mechanisms of p-chlorophenol-4-Chloroaniline bioremediation

Engineered bacteria are one of the greenest and most profitable biodegradation methods for removing noxious chlorophenols and chloramines from the environment. This study aims to acquire an engineering isolate Pseudomonas P1 that can effectively degrade 4-Chloroaniline (4-CA) and p-Chlorophenol (4-CP) simultaneously, and reveal potential differences in core gene expression and metabolic pathways in practical applications. A protein interaction network diagram was drawn using networkX under Python to count various topological properties of genes interaction network based on whole genome sequencing to reveal the interaction between proteins involved in organochlorine degradation. The core genes expression levels during aerobic degradation of the aforementioned compounds by Pseudomonas P1, which the most excellent degradation specifications at 30 °C, neutral pH and 100 mg/L, was analyzed based on transcriptome sequencing. Importantly, two major pathways exist in Pseudomonas P1 based on transcriptome sequencing during aerobic degradation of the aforementioned compounds. 4-chlorocatechol (4-CC) pathway of 4-CP degradation by multicomponent phenol hydroxylase (DmpONMLKP) and catechol 2,3-dioxygenase (DmpB), which expression levels were notably up-regulated 1.1–3.25 folds and DmpB was the most significant increased. GSH-dependent dehalogenation pathway including GSR, acpD, ahpF, yghU and katE genes to degrade 4-CA, which expression levels were significantly up-regulated 1.0–3.5 folds. The core genes expression changes were further verified by RTq-PCR. Collectively, our results provided an engineered bacteria that can efficiently mineralize 4-CA and 4-CP simultaneously, and clarified that it has two metabolic pathways regulate biodegradation of 4-CA and 4-CP, which can be practiced for in-site bioremediation of chlorophenols and chloramines co-contaminated soil.