Thurincin H is a bacteriocin produced by Bacillus thuringiensis with activity against a wide range of bacteria, including Gram positive and Gram negative. Disadvantages of producing thurincin H in B. thuringiensis is the low production level in the native strain probably due to the highly regulated mechanism of biosynthesis. The present study aimed to increase the synthesis of thurincin H produced by the native strain (Btm) through the establishment of additional copies of the structural gene (i.e. thnA) and the genes responsible for the bacterial self-immunity (thnRDE). Here, three recombinant strains of Btm were generated, harboring three, six and nine additional copies of thnA, and three with one copy of thnRDE upstream to the thnA copies. Data showed that the highest yield was obtained at 16 h using three additional copies of thnA (Btm/pHT-One) with a bacteriocin activity of 20,000 U/mg compared with the parental strain which showed 10,000 U/mg, increase of 100% in the production of the bacteriocin. Also, the addition of the genes responsible for self-immunity showed that recombinant B. thuringiensis (Btm/pHT-TwoRDE) can support six additional copies of thnA with an increase of 60% compared with the parental strain.

中文翻译：

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在天然生产菌株中提高苏林素H的产量。

Thurincin H是苏云金芽孢杆菌产生的一种细菌素，对多种细菌具有活性，包括革兰氏阳性和革兰氏阴性。在苏云金芽孢杆菌中生产苏林菌素H的缺点是天然菌株中的生产水平较低，这可能是由于生物合成的高度调控机制所致。本研究旨在通过建立结构基因（即thnA）和负责细菌自身免疫的基因（thnRDE）的其他拷贝，来增加天然菌株（Btm）产生的苏林素H的合成。在这里，产生了三株Btm的重组菌株，它们携带了三，六和九个额外的thnA拷贝，另外三个在thnA拷贝的上游带有一个拷贝的thnRDE。数据显示，使用三个额外拷贝的thnA（Btm / pHT-One）在16 h时可获得最高产量，细菌素活性为20,000 U / mg，而亲本菌株为10,000 U / mg，在190 U / mg下增加100％。细菌素的生产。另外，添加负责自身免疫的基因表明，重组苏云金芽孢杆菌（Btm / pHT-TwoRDE）可以支持6个额外的thnA拷贝，与亲本菌株相比增加60％。