Center for Sustainable Resource Science, RIKEN, Yokohama, Japan.
Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, Kobe, Japan.
Nat Commun. 2021 Apr 13;12(1):2195. doi: 10.1038/s41467-021-22504-6.
The C4 unsaturated compound 1,3-butadiene is an important monomer in synthetic rubber and engineering plastic production. However, microorganisms cannot directly produce 1,3-butadiene when glucose is used as a renewable carbon source via biological processes. In this study, we construct an artificial metabolic pathway for 1,3-butadiene production from glucose in Escherichia coli by combining the cis,cis-muconic acid (ccMA)-producing pathway together with tailored ferulic acid decarboxylase mutations. The rational design of the substrate-binding site of the enzyme by computational simulations improves ccMA decarboxylation and thus 1,3-butadiene production. We find that changing dissolved oxygen (DO) levels and controlling the pH are important factors for 1,3-butadiene production. Using DO-stat fed-batch fermentation, we produce 2.13 ± 0.17 g L 1,3-butadiene. The results indicate that we can produce unnatural/nonbiological compounds from glucose as a renewable carbon source via a rational enzyme design strategy.
C4 不饱和化合物 1,3-丁二烯是合成橡胶和工程塑料生产中的重要单体。然而，当葡萄糖作为可再生碳源通过生物过程时，微生物不能直接产生 1,3-丁二烯。在这项研究中，我们通过组合顺式，顺式-粘康酸（ccMA）-产生途径以及定制的阿魏酸脱羧酶突变，在大肠杆菌中构建了从葡萄糖生产 1,3-丁二烯的人工代谢途径。通过计算模拟对酶的底物结合位点进行合理设计，提高了 ccMA 的脱羧作用，从而提高了 1,3-丁二烯的产量。我们发现改变溶解氧（DO）水平和控制 pH 值是 1,3-丁二烯生产的重要因素。使用 DO -stat 补料分批发酵，我们生产了 2.13±0.17 g/L 的 1,3-丁二烯。结果表明，我们可以通过合理的酶设计策略，从葡萄糖等可再生碳源生产非天然/非生物化合物。
