豆豉中丁硫克百威降解菌的筛选及鉴定

郭薇丹; 肖毓; 林欣; 罗煜; 付湘晋

doi:10.13386/j.issn1002-0306.2020.20.014

豆豉中丁硫克百威降解菌的筛选及鉴定

Screening and Identification of Bacteria from Douchi to Degrade Carbosulfan

摘要

摘要: 以豆豉为筛选原料,采用逐步增加液体培养基中丁硫克百威的浓度对降解菌进行驯化富集,然后进行平板划线获得单菌落,采用高效液相色谱法测定降解菌株对丁硫克百威的降解率,降解率高于60%的菌进行PCR测序及序列比对,并对其降解丁硫克百威的影响因素进行研究。结果表明,筛选的14株降解率高的菌株的4株菌株降解率高于60%,其中JJ-1被鉴定为恶臭假单胞菌(Pseudomonas putida),JJ-4鉴定为毕赤酵母(Pichia pastoris),JJ-5鉴定为荧光假单胞菌(Pseudomonas fluorescens),JJ-8鉴定为柑桔青霉(Penicillium citrinum)。当pH=8时,JJ-4对丁硫克百威的降解率为50.87%,而此时丁硫克百威自身水解速率仅有5.29%,在环境温度25~40 ℃时,JJ-4对丁硫克百威的降解速率是丁硫克百威自身水解速率的2~3倍。菌株JJ-4降解丁硫克百威的最适pH为8,最适温度为35 ℃。JJ-4对丁硫克百威的降解速率符合一级动力学,拟合方程为C_t=36.189e^{0.1009 d}(R²=0.9912)。

Abstract: Using Douchi as the separation material,the degradation bacteria were domesticated and enriched by gradually increasing the concentration of carbosulfan in the liquid culture medium,and then the single colony was obtained by plate scribing. The degradation rate of carbosulfan was determined by HPLC,and 14 strains with high degradation rate were screened. Among them,four strains with degradation rate higher than 60% were sequenced and sequenced. Among them,JJ-1 was identified as Pseudomonas putida,JJ-4 as Pichia pastoris,JJ-5 as P.fluorescens,JJ-8 as Penicillium citrinum. In this paper,the factors influencing the degradation of carbosulfan by these four strains were studied. When pH=8,the degradation rate of JJ-4 was 50.87%,while the hydrolysis rate of itself was only 5.29%. At the ambient temperature of 25~40 ℃,the degradation rate of JJ-4 was 2~3 times of that of itself. The optimal pH and temperature of strain JJ-4 were 8 and 35 ℃. The degradation rate of JJ-4 to butaxyl Budweiser was in accordance with the first-order kinetics,and the fitting equation was C_t=36.189e^{0.1009 d}(R²=0.9912).