In silico aided metabolic engineering of Streptomyces roseosporus for daptomycin yield improvement
In silico aided metabolic engineering of Streptomyces roseosporus for daptomycin yield improvement
复制标题
计算机辅助玫瑰孢链霉菌代谢工程以提高达托霉素产量
DOI：
10.1007/s00253-011-3773-6
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发表时间：
2012-05-01
影响因子：
5
通讯作者：
Chen, Yunlin
中科院分区：
文献类型：
--
作者：
Huang, Di;Wen, Jianping;Chen, Yunlin
计算机模拟代谢网络模型是利用所需特性进行菌株改良的有价值的工具。通过比较玫瑰孢链霉菌代谢网络在两种不同目标函数下各途径的通量，确定了3个潜在的遗传修饰目标：zwf 2（编码葡萄糖-6-磷酸氢化酶）、dptI（编码α-酮戊二酸甲基转移酶）和dptJ（编码色氨酸加氧酶）。zwf 2、dptI和dptJ基因的过表达使达托霉素浓度分别增加至473.2、452.5和489.1 mg/L。此外，共过表达的三个基因在一系列导致了34.4%的高达托霉素浓度与亲本菌株相比，这归因于协同效应的酶负责达托霉素的生物合成。最后，工程菌在流加发酵中达托霉素的产量达到581.5mg/L，比出发菌株提高了43.2%。这些结果表明，基于计算机预测的代谢网络是准确的，合理的，实用的目标基因的鉴定和菌株的改进。
In silico metabolic network models are valuable tools for strain improvement with desired properties. In this work, based on the comparisons of each pathway flux under two different objective functions for the reconstructed metabolic network of Streptomyces roseosporus, three potential targets of zwf2 (code for glucose-6-phosphate hydrogenase), dptI (code for α-ketoglutarate methyltransferase), and dptJ (code for tryptophan oxygenase) were identified and selected for the genetic modifications. Overexpression of zwf2, dptI, and dptJ genes increased the daptomycin concentration up to 473.2, 452.5, and 489.1 mg/L, respectively. Furthermore, co-overexpression of three genes in series resulted in a 34.4% higher daptomycin concentration compared with the parental strain, which ascribed to the synergistic effect of the enzymes responsible for daptomycin biosynthesis. Finally, the engineered strain enhanced the yield of daptomycin up to 581.5 mg/L in the fed-batch culture, which was approximately 43.2% higher than that of the parental strain. These results demonstrated that the metabolic network based on in silico prediction would be accurate, reasonable, and practical for target gene identification and strain improvement.