Study on screening and characteristics of a dimethoate-degrading bacterium strain LGX1

A bacterium strain LGX1 was isolated from the soil samples which had been polluted by dimethoate for a long time with liquid enrichment culture.The strain was identified as Bacillus cereus on the basis of morphological observing and 16S rDNA sequence analysis.The optimum growth and degradation of dimethoste for the strain was 20%of inoculum concentration,100 mg·L-1 of initial molar concentration of dimethoate,2%of glucose,35 ℃of temperature and pH 4.0,respectively.The OD600 of the strain growth in phoxim,chlorpyrifos and triazophos as sole carbon source was significantly higher than in the dimethoate as the sole car-bon source in the basis salt-medium.These indicated that the strain LGX1 had a broad-spectrum degradability to organophosphorus pesticides.