Kim Seohyoung, Giraldo Néstor, Rainaldi Vittorio, Machens Fabian, Collas Florent, Kubis Armin, Kensy Frank, Bar-Even Arren, Lindner Steffen N
Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany.
b.fab GmbH, Köln, Germany.
Front Bioeng Biotechnol. 2023 Jan 16;11:1091899. doi: 10.3389/fbioe.2023.1091899. eCollection 2023.
Microbial C1 fixation has a vast potential to support a sustainable circular economy. Hence, several biotechnologically important microorganisms have been recently engineered for fixing C1 substrates. However, reports about C1-based bioproduction with these organisms are scarce. Here, we describe the optimization of a previously engineered formatotrophic strain. Short-term adaptive laboratory evolution enhanced biomass yield and accelerated growth of formatotrophic to 3.3 g-CDW/mol-formate and 6 h doubling time, respectively. Genome sequence analysis revealed that manipulation of acetate metabolism is the reason for better growth performance, verified by subsequent reverse engineering of the parental strain. Moreover, the improved strain is capable of growing to an OD of 22 in bioreactor fed-batch experiments, highlighting its potential use for industrial bioprocesses. Finally, demonstrating the strain's potential to support a sustainable, formate-based bioeconomy, lactate production from formate was engineered. The optimized strain generated 1.2 mM lactate -10% of the theoretical maximum- providing the first proof-of-concept application of the reductive glycine pathway for bioproduction.
微生物C1固定在支持可持续循环经济方面具有巨大潜力。因此，最近已对几种具有重要生物技术意义的微生物进行了工程改造，以固定C1底物。然而，关于利用这些生物体进行基于C1的生物生产的报道却很少。在此，我们描述了对先前工程化的甲酸营养型菌株的优化。短期适应性实验室进化分别提高了生物量产量，并将甲酸营养型菌株的生长加速至3.3 g-CDW/摩尔甲酸和6小时的倍增时间。基因组序列分析表明，乙酸代谢的调控是生长性能改善的原因，随后对亲本菌株进行的逆向工程验证了这一点。此外，改良菌株在生物反应器补料分批实验中能够生长至OD为22，突出了其在工业生物过程中的潜在用途。最后，为证明该菌株支持可持续的、基于甲酸的生物经济的潜力，设计了从甲酸生产乳酸的方法。优化后的菌株产生了1.2 mM乳酸——为理论最大值的10%——为还原甘氨酸途径在生物生产中的首次概念验证应用提供了证据。
