CAJ | 학술논문

从1株快速水解乳糖发酵产酸的凝结芽孢杆菌NL01的基因组上克隆获得了1个新的β－半乳糖苷酶基因，该基因长度为1998 bp，其编码的氨基酸序列与已经报道的β－半乳糖苷酶相似度低于40％。将该β－半乳糖苷酶基因整合到表达载体pETDuet－1上，并在大肠杆菌BL21（ DE3）中进行重组表达，β－半乳糖苷酶粗酶酶活为119?0μmol／（ min·mg），经镍柱纯化获得的重组β－半乳糖苷酶酶活为666?4μmol／（ min·mg）。利用该重组β－半乳糖苷酶水解乳糖，经TLC和HPLC分析显示该酶具有将乳糖水解为葡萄糖和半乳糖的活力，是一种新型的β－半乳糖苷酶。
종1주쾌속수해유당발효산산적응결아포간균NL01적기인조상극륭획득료1개신적β－반유당감매기인，해기인장도위1998 bp，기편마적안기산서렬여이경보도적β－반유당감매상사도저우40％。장해β－반유당감매기인정합도표체재체pETDuet－1상，병재대장간균BL21（ DE3）중진행중조표체，β－반유당감매조매매활위119?0μmol／（ min·mg），경얼주순화획득적중조β－반유당감매매활위666?4μmol／（ min·mg）。이용해중조β－반유당감매수해유당，경TLC화HPLC분석현시해매구유장유당수해위포도당화반유당적활력，시일충신형적β－반유당감매。
A novelβ-galactosidase gene was cloned from Bacillus coagulans NL01 which had ability to hydrolyze lactose into glucose and galactose in this study. The length of the β-galactosidase gene was 1 998 bp, and its coding sequence showed very low identity with other reported β-galactosidase. The gene was cloned into pETDuet-1 and expressed in Escherichia coli BL21( DE3) . The crude enzyme activity was 119.0 μmol/( min·mg) , and the purified enzyme activity was 666.4 μmol/( min·mg) after Ni-NTA purification. It was indicated from the analysis results of the hydrolysis prod?uct obtained by the purified β-galactosidase that this novel β-galactosidase presented high activity toward lactose con?version into glucose and galactose.