Optimization and Characterization of Nicosulfuron-Degrading Enzyme from Bacillus subtilis Strain YB1  

作　　者：KANG Zhan-hai Dong Jin-gao ZHANG Jin-lin 

机构地区：[1]College of Plant Protection, Agricultural University of Hebei, Baoding 071001, P.R, China [2]College of Life Sciences, Agricultural University of Hebei, Baoding 071001, P.R.China

出　　处：《Journal of Integrative Agriculture》2012年第9期1485-1492,共8页农业科学学报（英文版）

基　　金：the National Natural Science Foundation of China (31171877);the Youth Foundation Program for Science and Technology of Hebei Province, China (2010141)

摘　　要：A strain of Bacillus subtilis strain YB 1, isolated and preserved in our lab., showed a high nicosulfuron-degrading activity. Optimization of culture conditions on production of nicosulfuron-degrading enzyme from Bacillus subtilis strain YB 1 was carried out through mono-factor experiments. The characterization of degrading enzyme（s） was studied in this paper. The results showed that B. subtilis YB1 can use nicosulfuron as sole carbon source under aerobic condition. The key enzyme（s） involved in the initial biodegradation of nicosulfuron was localized to extracellular proteins and showed to be induced expressed. Enzyme-specific activity was up to 89.34 U mg-1 at pH 8.0 and 30℃, incubation for 96 h, inoculum 4.5x108 CFU mL-1 in Luria-Bertani liquid medium with nicosulfuron of 40 mg L-1. The maximum degradation rate of extracellular crude enzymes on nicosulfuron was 66% at pH 9.0, 35℃ in the enzymatic reaction system with nicosulfuron of 5 mg L-1. This degrading enzyme（s） was sensitive to high temperature, but kept high activity under alkaline conditions.A strain of Bacillus subtilis strain YB 1, isolated and preserved in our lab., showed a high nicosulfuron-degrading activity. Optimization of culture conditions on production of nicosulfuron-degrading enzyme from Bacillus subtilis strain YB 1 was carried out through mono-factor experiments. The characterization of degrading enzyme（s） was studied in this paper. The results showed that B. subtilis YB1 can use nicosulfuron as sole carbon source under aerobic condition. The key enzyme（s） involved in the initial biodegradation of nicosulfuron was localized to extracellular proteins and showed to be induced expressed. Enzyme-specific activity was up to 89.34 U mg-1 at pH 8.0 and 30℃, incubation for 96 h, inoculum 4.5x108 CFU mL-1 in Luria-Bertani liquid medium with nicosulfuron of 40 mg L-1. The maximum degradation rate of extracellular crude enzymes on nicosulfuron was 66% at pH 9.0, 35℃ in the enzymatic reaction system with nicosulfuron of 5 mg L-1. This degrading enzyme（s） was sensitive to high temperature, but kept high activity under alkaline conditions.

关 键 词：Bacillus subtilis NICOSULFURON microbial degradation ENZYME 

分 类 号：TQ920.1[轻工技术与工程—发酵工程] Q936[生物学—微生物学]