Biodegradation of endosulfan and endosulfan sulfate by Achromobacter xylosoxidans strain C8B in broth medium

Abstract

Endosulfan is one of the most widely used wide spectrum cyclodiene organochlorine insecticide. In environment, endosulfan can undergo either oxidation or hydrolysis reaction to form endosulfan sulfate and endosulfan diol respectively. Endosulfan sulfate is as toxic and as persistent as its parent isomers. In the present study, endosulfan degrading bacteria were isolated from soil through selective enrichment technique using sulfur free medium with endosulfan as sole sulfur source. Out of the 8 isolated bacterial strains, strain C8B was found to be the most efficient endosulfan degrader, degrading 94.12% α-endosulfan and 84.52% β-endosulfan. The bacterial strain was identified as Achromobacter xylosoxidans strain C8B on the basis of 16S rDNA sequence similarity. Achromobacter xylosoxidans strain C8B was also found to degrade 80.10% endosulfan sulfate using it as sulfur source. No known metabolites were found to be formed in the culture media during the entire course of degradation. Besides, the bacterial strain was found to degrade all the known endosulfan metabolites. There was marked increase in the quantity of released CO(2) from the culture media with endosulfan as sulfur source as compared to MgSO(4) suggesting that the bacterial strain, Achromobacter xylosoxidans strain C8B probably degraded endosulfan completely through the formation of endosulfan ether.

Detection of Achromobacter xylosoxidans in Hospital, Domestic, and Outdoor Environmental Samples and Comparison with Human Clinical Isolates

“…There are a few reports of A. xylosoxidans being found in outdoor environments, including in some plants (19,20), in polluted soils (21,22), and in an indoor swimming pool (23). Nevertheless, the natural habitat of this organism (24,25) as well as the possible sources of patient contamination remain unknown.…”

Isolation and Characterization of α-Endosulfan Degrading Bacteria from the Microflora of Cockroaches

“…However, it has a relatively reactive cyclic sulfite diester group and can serve as a good sulfur source (Sutherland et al, 2000). The removal of sulfur moiety from the endosulfan substantially reduced its vertabrate toxicity and therefore helped in detoxification of the compound (Goebel et al, 1982;Singh and Singh, 2011).…”

“…However, it has a relatively reactive cyclic sulfite diester group and can serve as a good sulfur source (Sutherland et al, 2000). The removal of sulfur moiety from the endosulfan substantially reduced its vertabrate toxicity and therefore helped in detoxification of the compound (Goebel et al, 1982;Singh and Singh, 2011).The isolated bacterial strains could degrade about 56.7-88.5% of 100 mg/l of α-endosulfan in 10 days of incubation. The difference in degradation capability of various strains may be due to difference in enzyme system and/or difference in their growth rate (Bhattacharjee et al, 2014).…”

Biodegradation of α-endosulfan via hydrolysis pathway by Stenotrophomonas maltophilia OG2

“…Previous studies have shown that microbial species prefer b-endosulfan for degradation over a-endosulfan (Siddique et al 2003;Goswami and Singh 2009). Biodegradation of endosulfan and its isomers by bacteria and fungi have been previously reported (Singh and Singh 2011;Kong et al 2013;Silambarasan and Abraham 2013;Kumar et al 2014;Ozdal et al 2016a). These microorganisms can utilize endosulfan either as carbon or sulfur source or both (Siddique et al 2003).…”

“…Although endosulfan is biodegradable in nature, its residues are found in environment (Weber et al 2010). Biodegradation is affected by a number of physicochemical environmental parameters such as energy source (electron donors), nutrients, pH, temperature, and substrate concentration (Hussain et al 2009;Singh and Singh 2011;Kong et al 2013).…”