蜡状芽孢杆菌菌株SMC的间甲酚降解特性及动力学

针对高浓度间甲酚废水难降解的问题,通过筛选获得一株高效降解间甲酚的菌株,并进一步探究其对间甲酚的降解特性和降解动力学.本文从某焦化厂活性污泥中经过驯化、筛选分离得到一株以间甲酚为唯一碳源的高效降解菌株,对其进行16S rDNA分子鉴定;通过测定培养液中间甲酚的剩余浓度,考察在菌株对间甲酚的最佳降解条件;并采用Haldane模型来模拟菌株降解间甲酚的动力学行为.将分离得到的菌株命名为SMC,初步鉴定为Bacillus cereus;在pH值为7.5、温度为30℃、摇床转速为150r/min的最佳培养条件下,菌株SMC在48h内对浓度1600mg/L的间甲酚降解率达97.81%,对间甲酚最大耐受能力为1900mg/L;经过Haldane模型拟合后的动力学参数为μ_max=0.01252h^-1,K_S=34.58mg/L,K_i=479.5mg/L(R²=0.932).菌株SMC对间甲酚有较强的降解能力,在高效处理含酚废水方面具有一定的应用前景.

Characteristics and kinetics study ofm-cresol biodegradation byBacillus cereus strain SMC

A bacterial strain SMC was isolated from the aerobic sludge of coking wastewater to resolve the problem of difficulty in treating effluent with high concentration of m-cresol. The characteristics and kinetics of degradation of m-cresol by the strain was investigated with m-cresol as sole source of carbon in the cultural medium. After isolation and screening,16S rDNA gene was analyzed to identify the taxonomic position of the strain. Its degradation capability under optimal growth conditions was studied by testing the concentration of m-cresol in residue medium. Haldane type substrate inhibit model was used to simulate cell growth on m-cresol. The isolated strain named as SMC belonged to Bacillus cereus. Under the optimal conditions of pH 7.5、30℃,150r/min of shaking rate,m-cresol with 1600mg/L initial concentration would be degraded 97.81% in 48h and the highest tolerance to m-cresol was 1900mg/L. The kinetic parameters were:μ_max=0.01252h^-1,K_S=34.58mg/L,K_i=479.5mg/L(R² = 0.932). SMC could degrade m-cresol effectively,with good application potential for wastewater containing high concentration of m-cresol.