Zhou Kang, Qiao Kangjian, Edgar Steven, Stephanopoulos Gregory
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
Nat Biotechnol. 2015 Apr;33(4):377-83. doi: 10.1038/nbt.3095. Epub 2015 Jan 5.
Metabolic engineering of microorganisms such as Escherichia coli and Saccharomyces cerevisiae to produce high-value natural metabolites is often done through functional reconstitution of long metabolic pathways. Problems arise when parts of pathways require specialized environments or compartments for optimal function. Here we solve this problem through co-culture of engineered organisms, each of which contains the part of the pathway that it is best suited to hosting. In one example, we divided the synthetic pathway for the acetylated diol paclitaxel precursor into two modules, expressed in either S. cerevisiae or E. coli, neither of which can produce the paclitaxel precursor on their own. Stable co-culture in the same bioreactor was achieved by designing a mutualistic relationship between the two species in which a metabolic intermediate produced by E. coli was used and functionalized by yeast. This synthetic consortium produced 33 mg/L oxygenated taxanes, including a monoacetylated dioxygenated taxane. The same method was also used to produce tanshinone precursors and functionalized sesquiterpenes.
对诸如大肠杆菌和酿酒酵母等微生物进行代谢工程改造以生产高价值天然代谢物,通常是通过对长代谢途径进行功能重构来实现的。当部分途径需要特殊环境或区室以实现最佳功能时,问题就会出现。在此,我们通过工程改造生物的共培养来解决这一问题,每种生物都包含其最适合承载的途径部分。在一个实例中,我们将乙酰化二醇紫杉醇前体的合成途径分为两个模块,分别在酿酒酵母或大肠杆菌中表达,二者单独都无法产生紫杉醇前体。通过设计这两个物种之间的互利关系,即在同一生物反应器中实现稳定共培养,其中大肠杆菌产生的代谢中间体被酵母利用并进行功能化修饰。这种合成菌群产生了33毫克/升的氧化紫杉烷,包括一种单乙酰化双氧化紫杉烷。同样的方法也被用于生产丹参酮前体和功能化倍半萜。