果蔬中残留毒死蜱农药降解菌的选育及鉴定

Screening and identification of bacteria for the degradation of residues chlorpyrifos pesticide on fruits and vegetables

为减少果蔬中残留毒死蜱农药,从长期喷洒有机磷农药的耕地土壤中,筛选到1株能高效降解毒死蜱农药的菌株并编号为DOP-Ma3。对其进行形态学和分子生物学鉴定,结果与Gen Bank上已提交的16S rDNA进行BLAST比对,由MEGA 6.0软件构建的系统发育树,结果表明该菌株与Burkholderia sp.16S rDNA序列同源性达99%,确定其归属于伯克霍尔德菌属。结合生理生化鉴定结果,确定此菌株为洋葱伯克霍尔德菌(Burkholderia cenocepacia)。实验证明,该菌株在48 h对500 mg/L毒死蜱降解率为69.87%,其降解酶为胞外酶,在35℃、30 min、p H 7.0条件下,粗酶液添加量为10%,对250 mg/L的毒死蜱进行降解,其降解率为52.47%。经验证,该菌对氧化乐果、氯氰菊酯和敌百虫也有一定的降解能力。

In order to reduce the chlorpyrifos pesticide residues on fruits and vegetables,a strain with high efficient degrading ability for chlorpyrifos pesticide was isolated from？ the arable soil sprayed with organophosphorus pesticide and named DOP-Ma3. Morphology analysis was carried out and the phylogenetic tree was generated by MEGA6. 0 software after comparison with homologous 16 S rDNA sequences from Gen Bank. Results showed that it was closely related to Burkholderia sp. with 99% of 16 S rDNA sequence homology. Based on the results of physiological and biochemical identification,the strain was determined as Burkholderia cenocepacia. The degradation rate of DOP-Ma3 was 69. 87% for 500 mg / L chlorpyrifos in 48 h. The degrading enzyme was extracellular enzyme. The degradation rate of 10% fermentation broth for 250 mg / L chlorpyrifos was 52. 47% after degradation at 35 ℃,pH 7. 0 for 30 min. It was proved that this bacteria also possessed the ability to degrade omethoate,cypermethrin,and dipterex.