Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Institute of Biochemistry, Charitéplatz 1, 10117, Berlin, Germany.
Nat Commun. 2023 Dec 20;14(1):8490. doi: 10.1038/s41467-023-44247-2.
One-carbon (C1) substrates, such as methanol or formate, are attractive feedstocks for circular bioeconomy. These substrates are typically converted into formaldehyde, serving as the entry point into metabolism. Here, we design an erythrulose monophosphate (EuMP) cycle for formaldehyde assimilation, leveraging a promiscuous dihydroxyacetone phosphate dependent aldolase as key enzyme. In silico modeling reveals that the cycle is highly energy-efficient, holding the potential for high bioproduct yields. Dissecting the EuMP into four modules, we use a stepwise strategy to demonstrate in vivo feasibility of the modules in E. coli sensor strains with sarcosine as formaldehyde source. From adaptive laboratory evolution for module integration, we identify key mutations enabling the accommodation of the EuMP reactions with endogenous metabolism. Overall, our study demonstrates the proof-of-concept for a highly efficient, new-to-nature formaldehyde assimilation pathway, opening a way for the development of a methylotrophic platform for a C1-fueled bioeconomy in the future.
一碳（C1）底物，如甲醇或甲酸盐，是循环生物经济有吸引力的原料。这些底物通常被转化为甲醛，作为进入新陈代谢的入口。在这里，我们设计了一个赤藓糖 1-磷酸（EuMP）循环来同化甲醛，利用一种混杂的依赖二羟丙酮磷酸的醛缩酶作为关键酶。计算机模拟表明，该循环具有很高的能量效率，有可能获得高生物产物产量。我们将 EuMP 分解为四个模块，使用逐步策略在以肌氨酸为甲醛来源的大肠杆菌传感器菌株中证明了模块的体内可行性。通过对模块整合的适应性实验室进化，我们确定了关键突变，使 EuMP 反应与内源性代谢相适应。总的来说，我们的研究证明了一种高效、新颖的自然甲醛同化途径的概念验证，为未来开发基于 C1 燃料的生物经济的甲基营养平台开辟了道路。
