产黑色素B.thuringiensis重组菌株的构建及其培养条件的优化

将嗜麦芽假单胞菌中产生黑色素的基因(mel gene)克隆到穿梭载体pHT3101中，并将它处于表达系统cry3A的控制下，构建得到重组质粒pHTAM．将此重组质粒用电脉冲的方法转入苏云金芽胞杆菌受体菌株BMB171中，得到重组菌株RSA．研究结果表明，处于cry3A控制下nel基因在BMBl71菌株中得到了成功的表达．本研究进一步采用红外光谱扫描法检测RSA所产黑色素的性质，并通过改变培养条件来提高黑色素的产量．

Construction of the Bacillus Thuringiensis Recombinant Strain with Melanin Formation and Research on the Condition of Producing Melanin

We subcloned the mel gene from Pseudomonas maltophilia, which is responsible for melanin formation, into shuttle vector pHT3101. The mel gene was inserted downstream of cry3A promoter. We transformed the two plasmids into BMB171(a mutant strain of Bacillus thuringiensis which can not produce crystal) and acquired a recombinant strains RSA. The research results revealed that the mel gene expressed under the control of cry3A promoter in BMB171. Furthermore, we detect the character of melanin produced by RSA and improve the yield of melanin by changing the cultural condition.