Liebal Ulf W, Blank Lars M, Ebert Birgitta E
Institute of Applied Microbiology-iAMB, Aachen Biology and Biotechnology-ABBt, RWTH Aachen University, Worringer Weg 1, D-52074 Aachen, Germany.
Metab Eng Commun. 2018 Jun 28;7:e00075. doi: 10.1016/j.mec.2018.e00075. eCollection 2018 Dec.
Microbial carbon dioxide assimilation and conversion to chemical platform molecules has the potential to be developed as economic, sustainable processes. The carbon dioxide assimilation can proceed by a variety of natural pathways and recently even synthetic CO fixation routes have been designed. Early assessment of the performance of the different carbon fixation alternatives within biotechnological processes is desirable to evaluate their potential. Here we applied stoichiometric metabolic modeling based on physiological and process data to evaluate different process variants for the conversion of C1 carbon compounds to the industrial relevant platform chemical succinic acid. We computationally analyzed the performance of cyanobacteria, acetogens, methylotrophs, and synthetic CO fixation pathways in in terms of production rates, product yields, and the optimization potential. This analysis provided insight into the economic feasibility and allowed to estimate the future industrial applicability by estimating overall production costs. With reported, or estimated data of engineered or wild type strains, none of the simulated microbial succinate production processes showed a performance allowing competitive production. The main limiting factors were identified as gas and photon transfer and metabolic activities whereas metabolic network structure was not restricting. In simulations with optimized parameters most process alternatives reached economically interesting values, hence, represent promising alternatives to sugar-based fermentations.
微生物二氧化碳同化及转化为化学平台分子有潜力发展成为经济、可持续的过程。二氧化碳同化可通过多种自然途径进行，最近甚至设计出了合成的二氧化碳固定途径。在生物技术过程中对不同二氧化碳固定替代方案的性能进行早期评估，有助于评估它们的潜力。在此，我们基于生理和过程数据应用化学计量代谢模型，以评估将C1碳化合物转化为工业相关平台化学品琥珀酸的不同过程变体。我们从生产率、产物产率和优化潜力方面，对蓝细菌、产乙酸菌、甲基营养菌和合成二氧化碳固定途径的性能进行了计算分析。该分析深入了解了经济可行性，并通过估算总体生产成本来估计未来的工业适用性。利用已报道的或估计的工程菌株或野生型菌株数据，模拟的微生物琥珀酸生产过程均未表现出具有竞争力的生产性能。主要限制因素被确定为气体和光子传递以及代谢活性，而代谢网络结构并无限制。在优化参数的模拟中，大多数过程替代方案达到了具有经济吸引力的值，因此，是基于糖发酵的有前景的替代方案。
