Colonization of Alcaligenes faecalis strain JBW4 in natural soils and its detoxification of endosulfan

Abstract

Alcaligenes faecalis strain JBW4, a strain of bacteria that is capable of degrading endosulfan, was inoculated into sterilized and natural soils spiked with endosulfan. JBW4 degraded 75.8 and 87.0 % of α-endosulfan and 58.5 and 69.5 % of β-endosulfan in sterilized and natural soils, respectively, after 77 days. Endosulfan ether and endosulfan lactone were the major metabolites that were detected by gas chromatography-mass spectrometry. This result suggested that A. faecalis strain JBW4 degrades endosulfan using a non-oxidative pathway in soils. The ability of strain JBW4 to colonize endosulfan-contaminated soils was confirmed by polymerase chain reaction-denaturing gradient gel electrophoresis. This result suggested that strain JBW4 competed with the original inhabitants in the soil to establish a balance and successfully colonize the soils. In addition, the detoxification of endosulfan by strain JBW4 was evaluated using single-cell gel electrophoresis and by determining the soil microbial biomass carbon and enzymatic activities. The results showed that the genotoxicity and ecotoxicity of endosulfan in soil were reduced after degradation. The natural degradation of endosulfan in soil is inadequate; therefore, JBW4 shows potential for the bioremediation of industrial soils that are contaminated with endosulfan residues.

Alcaligenes faecalis ZD02, a Novel Nematicidal Bacterium with an Extracellular Serine Protease Virulence Factor

“…This bacterium has wide applications in environmental protection. Some A. faecalis strains can be used to biodegrade organic pollutants and industrial wastewater because they can produce organic contaminant-degrading enzymes (16,17). For example, A. faecalis subsp.…”

“…phenolicus, isolated from a gray water bioprocessor, is a phenol-degrading bacterium (16). A. faecalis JBW4, isolated from activated sludge, has been reported to be capable of degrading the organochlorine pesticide endosulfan in soils (17). A. faecalis has also been shown to degrade petroleum hydrocarbons, which makes A. faecalis an excellent candidate for the bioremediation of hydrocarbon pollution (34).…”

“…Here, we report that the Alcaligenes bacterium A. faecalis ZD02 has toxicity against M. incognita. In comparison with other known nematicidal bacteria, a huge advantage of using A. faecalis as a microbial nematicide is that A. faecalis is capable of colonizing organisms in soil (17). This feature can make the strain a dominant bacterium in rhizosphere soil and can increase the probability of its coming into contact with RKNs.…”

“…Currently, this bacterium has wide applications in the sewage treatment and pharmaceutical industries. Some A. faecalis strains produce enzymes that degrade organic contaminants and can be applicable in the biodegradation of organic pollutants and industrial wastewater in environmental industry (16,17). Additionally, a number of A. faecalis strains can produce R-(Ϫ)-mandelic acid, an important precursor to various drugs (18,19).…”

Biodegradation of DDE and DDT by Bacterial Strain Stenotrophomonas sp. DXZ9

“…Su [36] reported the toxicity test of the degradation product of Atrazine by a micronucleus test of the root tip (Vicia faba). Kong [37] studied the toxic bioassay of the degrading product of endosulfan through the coelomocyte of the earthworm by single cell gel electrophoresis (SCGE) by measuring the soil microbial biomass carbon and enzymatic activities. The detoxification of endosulfan by the JBW4 strain was evaluated, and it has been verified that the genotoxicity and ecotoxicity of endosulfan in the soil were effectively reduced after biodegradation by the JBW4 strain.…”