Isolation, Identification, Degradation Characteristics And Application Of Carbendazim-Degrading Bacteria

Two strains were isolated from soil of CDPZ, they can use the carbendazim as thesole carbon and nitrogen source to grow. According to morphological, physiologicaland biochemical analysis and the analysis of16S rDNA gene sequence, the two strainswere identified as Pseudomonas sp. GRPD-1and Enterobacter sp. YE-2. And theEnterobacter sp. which could degrade carbendazim is firstly reported in China.The relationship between the growth and carbendazim degradation of strains wassurveyed. The result showed that if the amount of the strain increase, the carbendazimcontent will be decreased. The effect of the different carbon sources, nitrogen sources,pH, temperature, inoculums size as single factor on the carbendazim degradation werealso observed. The experimental results indicated that strain GRPD-1’s degradation rateincreased to91.2%when the additional carbon source is glucose, nitrogen source ispeptone, pH is7.0, temperature is30℃, inoculum size is9%. The strain YE-2’sdegradation rate increased to94.5%when the additional carbon source is glucose,nitrogen source is peptone, pH is7.0, temperature is30℃, inoculum size is7%.The strains’ protein content and enzyme activity were measured after cultured twodays in the degradation medium. The results showed that their carbendazimdegeneration enzyme are extracellular enzyme. Combined with SDS-PAGEelectrophoresis analysis the protease constituent and molecular weight. It indicated thetwo strains secrete induced enzyme. GRPD-1’s degrading enzyme is three, molecular weight are during33.0KDa~66.2KDa and the YE-2’s degrading enzyme is four,molecular weight are more than94.0KDa.The two strains were embedded by sodium alginate. When GRPD-1acted on the50mg/L carbendazim in sterile water, its degradation rate increased34%, YE-2increased35%, compared to untreated. Choose YE-2to act on the soil, the soil has10mg carbendazim per gram, measured the content of carbendazim after4,8,12days.The residual quantity of the carbendazim was less than0.4mg in twentieth day,degradation rate was more than96%, almost completely cleared the whole carbendazim.In conclusion, the preliminary wok about GRPD-1and YE-2demonstrates they havebroad application prospects in the actual water and soil bioremediation.