Pyruvate is a central metabolite for the biological production of various chemicals. In eukaryotes, pyruvate produced by glycolysis is used in conversion to ethanol and lactate and in anabolic metabolism in the cytosol, or is transported into the mitochondria for use as a substrate in the tricarboxylic acid (TCA) cycle. In this study, we focused on controlling pyruvate metabolism in aerobic microorganisms for the biological production of various chemicals. We successfully improved productivity by redirecting pyruvate metabolism in the aerobic filamentous fungus Aspergillus oryzae via the deletion of two genes that encode pyruvate decarboxylase and mitochondrial pyruvate carriers. Production of ethanol as a major byproduct was completely inhibited, and the limited translocation of pyruvate into the mitochondria shifted the metabolism from respiration for energy conversion to the effective production of lactate or 2,3-butandiole, even under aerobic conditions. Metabolomic and transcriptomic analyses showed an emphasis on glycolysis and a repressed TCA cycle. Although the dry mycelial weights of the deletion mutants were reduced compared with those of wild type, the titer and yields of the target products were drastically increased. In particular, the redirection of pyruvate metabolism shifted from anabolism for biomass production to catabolism for the production of target chemicals. Conclusively, our results indicate that the redirection of pyruvate metabolism is a useful strategy in the metabolic engineering of aerobic microorganisms.

丙酮酸是各种化学品生物生产的中心代谢物。在真核生物中，由糖酵解产生的丙酮酸用于转化为乙醇和乳酸以及细胞质中的合成代谢，或者被转运到线粒体中用作三羧酸 (TCA) 循环的底物。在这项研究中，我们专注于控制好氧微生物中的丙酮酸代谢，以生物生产各种化学品。我们通过重新定向需氧丝状真菌米曲霉中的丙酮酸代谢，成功提高了生产力通过删除编码丙酮酸脱羧酶和线粒体丙酮酸载体的两个基因。乙醇作为主要副产品的生产被完全抑制，丙酮酸进入线粒体的有限易位将代谢从用于能量转换的呼吸转变为有效生产乳酸或 2,3-丁二醇，即使在有氧条件下也是如此。代谢组学和转录组学分析显示重点是糖酵解和受抑制的 TCA 循环。尽管与野生型相比，缺失突变体的干菌丝体重量有所降低，但目标产物的滴度和产量却急剧增加。特别是，丙酮酸代谢的重新定向从生物质生产的合成代谢转变为目标化学品生产的分解代谢。最后，