Efficient biosynthesis of (2S)-pinocembrin from d-glucose by integrating engineering central metabolic pathways with a pH-shift control strategy.
Efficient biosynthesis of (2S)-pinocembrin from d-glucose by integrating engineering central metabolic pathways with a pH-shift control strategy.
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DOI：
10.1016/j.biortech.2016.07.066
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发表时间：
2016-10
影响因子：
11.4
通讯作者：
Junjun Wu;Xia Zhang;Jingwen Zhou;Mingsheng Dong
中科院分区：
文献类型：
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作者：
Junjun Wu;Xia Zhang;Jingwen Zhou;Mingsheng Dong
微生物发酵有望彻底改变从天然植物中提取(2S)-匹诺曹蛋白的传统方法。以前开发了一种用于一步法(2S)-皮诺曹蛋白生产的大肠杆菌结集系统。然而，这种发酵平台需要补充昂贵的丙二醇-辅酶a前体丙二酸盐，并需要morpholino丙烷磺酸盐提供缓冲能力。本文构建了一个规则间隔的短回文重复干扰簇，以有效地引导碳通量流向丙二酰辅酶a。通过探索不同培养pH对微生物发酵的影响，发现pH值高有利于上游途径催化，pH值低有利于下游途径催化。在此基础上，提出了两阶段pH控制策略。0 ~ 10 h pH控制在7.0,10 h后pH调至6.5，最终(2S)-匹诺诺匹林滴度升高至525.8 mg/L。这些结果是在最小的培养基中获得的，没有额外的前体补充，从而为工业规模低成本生产黄酮类化合物提供了机会。
Microbial fermentations promise to revolutionize the conventional extraction of (2S)-pinocembrin from natural plant sources. Previously anEscherichia colifermentation system was developed for one-step (2S)-pinocembrin production. However, this fermentation platform need supplementation of expensive malonyl-CoA precursor malonate and requires morpholinopropane sulfonate to provide buffering capacity. Here, a clustered regularly interspaced short palindromic repeats interference was constructed to efficiently channel carbon flux toward malonyl-CoA. By exploring the effects of different culture pH on microbial fermentation, it was found that high pH values favored upstream pathway catalysis, while low pH values favored downstream pathway catalysis. Based on this theory, a two-stage pH control strategy was proposed. The pH was controlled at 7.0 during 0–10 h, and was shifted to 6.5 after 10 h. Finally, the (2S)-pinocembrin titers increased to 525.8 mg/L. These results were attained in minimal medium without additional precursor supplementation, thus offering opportunities for industrial scale low-cost production of flavonoids.