Department of Biosystems Science and Engineering, ETH Zurich, Basel 4058, Switzerland.
Department of Biosystems Science and Engineering, ETH Zurich, Basel 4058, Switzerland.
Metab Eng. 2017 Mar;40:33-40. doi: 10.1016/j.ymben.2016.12.013. Epub 2017 Jan 3.
Biotin is an archetypal vitamin used as cofactor for carboxylation reactions found in all forms of life. However, biotin biosynthesis is an elaborate multi-enzymatic process and metabolically costly. Moreover, many industrially relevant organisms are incapable of biotin synthesis resulting in the requirement to supplement defined media. Here we describe the creation of biotin-independent strains of Escherichia coli and Corynebacterium glutamicum through installation of an optimized malonyl-CoA bypass, which re-routes natural fatty acid synthesis, rendering the previously essential vitamin completely obsolete. We utilize biotin-independent E. coli for the production of the high-value protein streptavidin which was hitherto restricted because of toxic effects due to biotin depletion. The engineered strain revealed significantly improved streptavidin production resulting in the highest titers and productivities reported for this protein to date.
生物素是一种典型的维生素，作为所有生命形式中羧化反应的辅助因子。然而，生物素的生物合成是一个复杂的多酶过程，代谢成本很高。此外，许多具有工业应用价值的生物体无法进行生物素合成，因此需要补充特定的培养基。在这里，我们通过安装优化的丙二酰辅酶 A 旁路来构建生物素非依赖性大肠杆菌和谷氨酸棒状杆菌，该旁路重新构建了天然脂肪酸合成途径，使以前必需的维生素变得完全多余。我们利用生物素非依赖性大肠杆菌生产高价值蛋白质链霉亲和素，由于生物素耗尽导致毒性作用，以前这种蛋白的生产受到限制。该工程菌株显示出显著提高的链霉亲和素生产能力，达到了迄今为止该蛋白报道的最高滴度和产率。
