Characterization of a Pyrethroid-Degrading Pseudomonas fulva Strain P31 and Biochemical Degradation Pathway of D-Phenothrin

Abstract

D-phenothrin is one of the most popular pyrethroid insecticides for its broad spectrum and high insecticidal activity. However, continuous use of D-phenothrin has resulted in serious environmental contamination and raised public concern about its impact on human health. Biodegradation of D-phenothrin has never been investigated and its metabolic behaviors remain unknown. Here, a novel bacterial strain P31 was isolated from active sludge, which completely degraded (100%) D-phenothrin at 50 mg⋅L-1 in 72 h. Based on the morphology, 16S rRNA gene and Biolog tests, the strain was identified as Pseudomonas fulva. Biodegradation conditions were optimized as 29.5°C and pH 7.3 by utilizing response surface methodology. Strain P31 depicted high tolerance and strong D-phenothrin degradation ability through hydrolysis pathway. Strain P31 degraded D-phenothrin at inhibition constant (Ki) of 482.1673 mg⋅L-1 and maximum specific degradation constant (qmax) of 0.0455 h-1 whereas critical inhibitor concentration remained as 41.1189 mg⋅L-1. The 3-Phenoxybenzaldehyde and 1,2-benzenedicarboxylic butyl dacyl ester were identified as the major intermediate metabolites of D-phenothrin degradation pathway through high-performance liquid chromatography and gas chromatography-mass spectrometry. Bioaugmentation of D-phenothrin-contaminated soils with strain P31 dramatically enhanced its degradation, and over 75% of D-phenothrin was removed from soils within 10 days. Moreover, the strain illustrated a remarkable capacity to degrade other synthetic pyrethroids, including permethrin, cyhalothrin, β-cypermethrin, deltamethrin, fenpropathrin, and bifenthrin, exhibiting great potential in bioremediation of pyrethroid-contaminated environment.

All-electrical monitoring of bacterial antibiotic susceptibility in a microfluidic device

“…The inset shows t d values obtained from linear fits to the natural logarithms of the growth curves. The t d we measure are longer than those reported in the literature [29][30][31], possibly due to the limited availability of nutrients in the microchannels [32].…”

New Insights into the Microbial Degradation of D-Cyphenothrin in Contaminated Water/Soil Environments

“…Several pyrethroid-degrading microbes were reported and effectively removed pyrethroids under optimum conditions in liquid media, but few were subjected to soil remediation [33,40,42,52,53]. The degrading microbes isolated from the environment usually fail to degrade xenobiotics when used for bioremediation of contaminated soils; thus, additional treatments are needed to accelerate biodegradation [23,43,54]. In this work, bioaugmentation of D-cyphenothrin-contaminated soils with strain HLJ-10 substantially enhanced the disappearance rate of D-cyphenothrin, and its t 1/2 was reduced by 31.0 and 24.7 d in sterile and nonsterile soils, respectively, in comparison with soils without the strain HLJ-10.…”

“…These intermediates were transient with very low concentrations and easily transformed into smaller molecular compounds through oxidation and hydrolysis. Microbial degradation of pyrethroids mainly involves the hydrolysis of ester bonds and oxidation reaction [23]. Carboxylesterase enzyme is produced by the microorganism that specifically cleaves a carboxylate bond [44,45].…”

Insights Into the Biodegradation of Lindane (γ-Hexachlorocyclohexane) Using a Microbial System

“…The bacterial degradation of lindane and other xenobiotics are widely reported (Chen et al, 2012(Chen et al, , 2013Yang et al, 2018;Zhang H. et al, 2018;Bhatt et al, 2020c). Bacterial cells use organic pollutants as a sole source of carbon and nitrogen (Chen et al, 2011(Chen et al, , 2014Zhan et al, 2018b;Lin et al, 2020).…”