青霉素酶基因在枯草芽孢杆菌中的高效表达

以获得大量胞外青霉素酶为目的，将青霉素酶基因克隆至表达载体pWB980中，并转化到双蛋白酶缺陷的Bacillus subtilis DB104。重组菌在LB培养基中培养24小时后， SDS-PAGE分析发现目的蛋白分子量为28kDa，酶活力为339U/mL；通过筛选7种不同的发酵培养基发现4#培养基更利于青霉素酶的表达，最大酶活力为1580U/mL，较优化前提高了3.66倍，并对该重组菌进行了7L罐放大实验，结果显示在培养24小时产酶达到高峰，酶活力为1255.8 U/mL。

High-Level Expression of Penicillinase Gene in Bacillus Subtilis

To obtain a number of extracellular penicillinase,the gene(penp)encoding penicillinse of Bacillus cereus ATCC10987 was cloned into expression vector in Bacillus subtilis,transformed into Bacillus subtilis DB104 deficient in two proteases.When recombinant bacteria was cultured in LB medium for 24 hours,the result of SDS-PAGE showed that the molecular weight of the protein was 28kDa and the penicillinase activity reached 339U/ml.By screening seven different fermentation media,the result showed that 4# medium is favorable to producing penicillinase by the recombinant cells than the others,with the yield of the enzyme being 1580U/ml.When the recombinant cells was cultured in 7 liter fermentor for 24h,the penicillinase activity reached 1255.8U/ml.