甲基对硫磷降解菌PF32的分离鉴定及其降解特性研究

Isolation and Characterization of Capable of Degrading Parathion-methyl Bacterium Stenotrophomonas sp. PF32

从某农药厂采集污泥,采用驯化富集的方式分离得到1株能以甲基对硫磷为唯一碳源生长的菌株,命名为PF32。根据表型特征、生理生化特性和16SrRNA基因序列相似性分析,鉴定该菌株为寡养单胞菌Stenotrophomonas sp.。PF32能在24h内降解浓度为100mg/L的甲基对硫磷,降解率99%以上。PF32降解甲基对硫磷的最适pH值为7.0,最适温度为30℃,该菌降解甲基对硫磷的速率和起始接种量呈正相关。降解谱试验结果表明,PF32对辛硫磷、倍硫磷、杀螟硫磷、三唑磷、毒死蜱也有较好的降解效果。

A strain of bacterium PF32,capable of utilizing parathion-methyl as the sole carbon source for growth,was isolated from the sludge of a pesticide plant after taming and enrichment. Strain PF32 was identified as Stenotrophomonas sp. on analysis of its phenotype,physiological-biochemical characteristics and the similarity analysis of its 16S rRNA sequence. Strain PF32 could degrade about 99% of 100 mg/L parathion-methyl at 24h after inoculation.The optimal pH value and temperature for parathion-methyl degradation by PF32 was 7.0 and 30℃,respectively.The degradation rate was positive to initial inoculum rate.Strain PF32 also could degrade other organophosphorus pesticides such as phoxim,fenthion,fenitrothion,triazophos and chlorpyrifos quickly.