Development of an autofluorescent organophosphates-degrading Stenotrophomonas sp. with dehalogenase activity for the biodegradation of hexachlorocyclohexane (HCH).

Simultaneous biodegradation of hexachlorocyclohexane (HCH) and organophosphates (OPs) by a recombinant Stenotrophomonas sp. was studied in the study. The broad-host-range plasmid pVGAB, harboring enhanced green fluorescent protein gene (egfp) and dehalogenase genes (linA and linB), was constructed and transformed into the OP-degrading strain Stenotrophomonas YC-1 to get the recombinant strain YC-H. Over-expression of dehalogenase (LinA and LinB) and enhanced green fluorescent protein (EGFP) was obtained in YC-H by determining their enzymatic activities and fluorescence intensity. YC-H was capable of rapidly and simultaneously degrading 10mg/l gamma-HCH and 100mg/l methyl parathion (MP) determined by GC-ECD analysis. A bioremediation assay with YC-H inoculated into fumigated and nonfumigated soil showed that both 10mg/kg gamma-HCH and 100mg/kg MP could be completely degraded within 32 days. The novel EGFP-marked bacterium could be potentially applied in the field-scale decontamination of HCH and OPs residues in the environment.