摘要
枯草芽胞杆菌Bacillus subtilis是一种高产的外源基因表达菌株,外源蛋白能大量分泌到细胞外培养基中。从地衣芽孢杆菌ATCC14580基因组中克隆胞外脂肪酶全基因序列,并构建枯草芽孢杆菌表达载体pACC-pUB110,得到脂肪酶基因重组载体。该表达载体有一个强启动子,经淀粉诱导能高效表达外源蛋白,以枯草芽孢杆菌胞外蛋白酶缺失型菌株WB700和野生型菌株B.subtilis168为宿主菌,得到的脂肪酶以对硝基苯棕榈酸酯为底物,测得培养基上清总活力达到76.8μ/mL。该脂肪酶在pH10-10.5表现最大水解活力,最适反应温度为37℃,在强碱条件下稳定性很好。
Bacillus subtilis is an efficient host for heterologous gene expression. It can secrete heterologous proteins to culture medium directly. The authors clon the extracellular lipase gene bli02525 from Bacillus licheniformis and construct recombinant expression vector pACC-pUB110 containing a length of a strong promoter induced by soluble starch which can promote high-level expression of protein. The gene bli02525 is expressed in wild type bacterium plant Bacillus subtilis-168 and proteinase-absent type bacterium plant WB700. The total activity of the culture enzyme is up to 76. 8 units/ml with p-nitrophenyl-palmitate as substrate. The lipase displayed optimal catalytic activity towards pNPP in the extreme alkaline region of pH 10. 0-10. 5, exhibites maximum activity at 37℃, and is stable at the extreme alkaline conditions.
出处
《浙江理工大学学报(自然科学版)》
2009年第5期757-763,共7页
Journal of Zhejiang Sci-Tech University(Natural Sciences)