Co-metabolic biodegradation of 4-bromophenol in a mixture of pollutants system by Arthrobacter chlorophenolicus A6.

Mitali Madhusmita Sahoo,Sangeeta Raut,Naresh Kumar Sahoo,Achlesh Daverey

doi:10.1007/s10646-021-02508-0

Mitali Madhusmita Sahoo, Sangeeta Raut + Show 2 more

Open Access

https://doi.org/10.1007/s10646-021-02508-0

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Abstract

Brominated phenols are listed as priority pollutants together with nitrophenol and chlorophenol are the key components of paper pulp wastewater. However, the biodegradation of bromophenol in a mixed substrate system is very scanty. In the present investigation, simultaneous biodegradation kinetics of three substituted phenols 4-bromophenol (4-BP), 4-nitrophenol (4-NP), and 4-chlorophenol (4-CP) were investigated using Arthrobacter chlorophenolicus A6. A 23 full factorial design was applied with varying 4-BP and 4-CP from 75-125 mg/L and 4-NP from 50-100 mg/L. Almost complete degradation of this mixture of substituted phenols was achieved at initial concentration combinations of 125, 125, and 100 mg/L of 4-CP, 4-BP, and 4-NP, respectively, in 68 h. Statistical analysis of the results revealed that, among the three variables, 4-NP had the most prominent influence on the degradation of both 4-CP and 4-BP, while the concentration of 4-CP had a strong negative interaction effect on the biodegradation of 4-NP. Irrespective of the concentration levels of these three substrates, 4-NP was preferentially biodegraded over 4-CP and 4-BP. Furthermore, 4-BP biodegradation rates were found to be higher than those of 4-CP, followed by 4-NP. Besides, the variation of the biomass yield coefficient of the culture was investigated at different initial concentration combinations of these substituted phenols. Although the actinomycetes consumed 4-NP at a faster rate, the biomass yield was very poor. This revealed that the microbial cells were more stressed when grown on 4-NP compared to 4-BP and 4-CP. Overall, this study revealed the potential of A. chlorophenolicus A6 for the degradation of 4-BP in mixed substrate systems.

Highlights

Bromophenols are widely discharged from the effluent of different industries such as; brominated flame retardants, dyes, paints, photographic, pulps, polymer and resin intermediates, pesticides, herbicides, and wood preservatives (Saeed et al 2016; Xu etal. 2017; Li et al 2015)
Almost complete degradation of this mixture of substituted phenols was achieved at an initial concentration combination of 125, 125, and 100 mgl− 1of 4-CP, 4-BP, and 4-NP, respectively in 68 h
This study revealed the prospective of A. chlorophenolicus A6 for the degradation of 4-BP in mixed substrate systems

Summary

Introduction

Bromophenols are widely discharged from the effluent of different industries such as; brominated flame retardants, dyes, paints, photographic, pulps, polymer and resin intermediates, pesticides, herbicides, and wood preservatives (Saeed et al 2016; Xu etal. 2017; Li et al 2015). Bromophenols are widely discharged from the effluent of different industries such as; brominated flame retardants, dyes, paints, photographic, pulps, polymer and resin intermediates, pesticides, herbicides, and wood preservatives The concentration of bromophenol rises to 187 mgl− 1 in the effluent of photographic industrial wastewater (Sahoo et al 2014a). Phenolic pollutants undergo active transformation inside the living organisms by cytochrome P450 enzyme system and generate more toxic electrophilic metabolites. These active metabolites may bind and impair the DNA or other vital enzymes system of the living organisms, causes mutagenicity and carcinogenicity (Dayana and Bakthavatsalam 2019). Owing to its acute genotoxic, hepatocytes, thyrotoxic, neurotoxic and carcinogenic properties, phenolic compounds are considered as priority pollutants by USEPA (Acosta et al 2018; Zou et al 2016; Sharma and Dutta 2018; Liang et al 2019; Peng et al 2017)

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