Presence of esterase and laccase in Bacillus subtilis facilitates biodegradation and detoxification of cypermethrin

Abstract

Ubiquitous presence of cypermethrin as a contaminant in surface stream and soil necessitates to develop potential bioremediation methods to degrade and eliminate this pollutant from the environment. A cypermethrin utilizing bacterial strain (MIC, 450 ppm) was isolated from the soil of pesticide contaminated agriculture field and characterized by using polyphasic approach. On molecular basis bacterial isolate showed 98% homology with Bacillus subtilis strain 1D. Under optimized growth conditions, bacteria showed 95% degradation of cypermethrin after 15 days and the end products of cypermethrin biodegradation under aerobic conditions were cyclododecylamine, phenol, 3-(2,2-dichloroethenyl 2,2-dimethyl cyclopropane carboxylate,1-decanol,chloroacetic acid, acetic acid, cyclopentan palmitoleic acid, and decanoic acid. Amplification of esterase (700 bp) and laccase (1200 bp) genes was confirmed by PCR which showed a possible role of these enzymes in biodegradation of cypermethrin. In the presence of cypermethrin Km value(s) of both the enzymes was low than the control. A nobel cypermethrin degradation pathway followed by B. subtilis was proposed on the basis of characterization of biodegraded products of cypermethrin using GC-MS. Cypermethrin biodegradation ability of Bacillus subtilis strain 1D without producing any toxic end product reveals the potential of this organism in cleaning of pesticide contaminated soil and water.

Enhanced Cypermethrin Degradation Kinetics and Metabolic Pathway in Bacillus thuringiensis Strain SG4

“…We confirmed that strain SG4 produced non-toxic intermediates while effectively degrading cypermethrin. Our results aligned with previous reports on other bacterial strains [28,30,43]. Hydrolysis of cypermethrin was mediated via the cleavage of the ester bond, resulting in the formation of acid and alcohol [1].…”

“…B. thuringiensis (Bt) is a bacterium well-known for its broad capabilities and it is widely used in biological control [42]. Bt has been reported for the degradation of cypermethrin and other pyrethroids [17,42,43]. However, the potential use of Bt in the bioremediation of pyrethroid-contaminated environments has not received adequate attention.…”

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

“…One novel approach to enzyme immobilization is based on the entrapment of magnetic nanoparticles via epoxy cross-linking. This technique can be employed to improve the activity of pollutant degradation bacteria, fungi, or heterologous-expressed enzymes (Iype et al, 2017;Gangola et al, 2018). Recent high throughput techniques can be used to explore key functional strains from the pesticide degradation microbial community and fulfill the gap between laboratory cultures and large-scale applications .…”

Bacilli-Mediated Degradation of Xenobiotic Compounds and Heavy Metals

“…The degradation of cypermethrin is well-studied in some Bacilli including Bacillus sp. SG2 (Pankaj et al, 2016 ), B. subtilis BSF01 (Xiao et al, 2015 ), B. subtilis strain 1D (Gangola et al, 2018 ), Bacillus sp. AKD1 (Tiwary and Dubey, 2016 ), Bacillus sp.…”

“…The phenyl ester of o -phenoxy benzoic acid was degraded via the formation of phenol-M-tert-butyl, phenol, and aliphatic hydrocarbons or short-chain compounds. Another pathway of degradation of cypermethrin was studied in B. subtilis strain 1D (Gangola et al, 2018 ). In this pathway, cypermethrin was initially transformed into 3-(2, 2-dichloro ethenyl)-2,2-dimethyl-cyclopropanecarboxylate and cyclododecylamine due to hydrolysis of the ester linkage ( Figure 5 ).…”