农杆菌转化法高效构建顶头孢霉sorA和sorB双缺失菌株提高头孢菌素C产量

目的获得顶头孢霉sorA和sorB双缺失菌株,以阻断sorbicillinoids的合成,并研究其与头孢菌素C(CPC)产量的关系。方法通过根癌农杆菌转化法,依据同源双交换的原理,同时敲除合成sorbicillinoids骨架结构的两个聚酮合酶基因sorA和sorB,并通过摇瓶发酵实验检测缺失菌和野生菌的产量。结果筛选并验证了6株A.chrysogenum-Δpks菌株,遗传稳定,转化效率约为20%。通过发酵实验测定发现,缺失菌株产CPC能力比野生菌提高了70%。结论农杆菌转化法是一个高效的顶头孢霉遗传操作系统,并且顶头孢霉中sorbicillinoids的缺失可以提高CPC产量。

Simultaneous deletion of sorA and sorB using highly efficient Agrobacterium-mediated transformation enhanced cephalosporin C production in Acremonium chrysogenum

Objective To block the biosynthetic pathway of sorbicillinoids in Acremonium chrysogenum by knocking out sorA and sorB simultaneously and investigate the relationship between sorbicillinoids biosynthesis and cephalosporin C (CPC) production. Methods The Agrobacterium-mediated transformation was used to delete two polyketide synthase genes sorA and sorB simultaneously through homologous recombination, which are responsible for the assembly of the core sorbicillinoids structure. Subsequent shaking flask fermentation experiment was carried out to measure the CPC production of the mutant and the wild-type strain. Results Six A. chrysogenum-Δpks strains were obtained with a transformation efficiency up to 20%. The CPC titer of the mutant was increased by 70% compared with that of the wild-type strain. Conclusion Agrobacterium-mediated transformation is highly efficient for the genetic modification in A. chrysogenum, and the loss of sorbicillinoids biosynthesis resulted in an increased CPC yield.