Succinic acid (SA), a valuable chemical compound with a broad range of industrial uses, has become a subject of global interest in recent years. The bio-based production of SA by highly efficient microbial producers from renewable feedstock is significantly important, regarding the current trend of sustainable development. In this study, a novel bacterial strain, LU2, was isolated from cow rumen and recognized as an efficient producer of SA from lactose. Proteomic and genetic identifications as well as phylogenetic analysis were performed, and strain LU2 was classified as an Enterobacter aerogenes species. The optimal conditions for SA production were 100 g/L lactose, 10 g/L yeast extract, and 20% inoculum at pH 7.0 and 34 °C. Under these conditions, approximately 51.35 g/L SA with a yield of 53% was produced when batch fermentation was conducted in a 3-L stirred bioreactor. When lactose was replaced with whey permeate, the highest SA concentration of 57.7 g/L was achieved with a yield and total productivity of 62% and 0.34 g/(L*h), respectively. The highest productivity of 0.67 g/(L*h) was observed from 48 to 72 h of batch fermentation, when E. aerogenes LU2 produced 16.23 g/L SA. This study shows that the newly isolated strain E. aerogenes LU2 has great potential as a new biocatalyst for producing SA from whey permeate.

中文翻译：

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一种新型生物催化剂，产气肠杆菌 LU2，用于使用乳清渗透液作为具有成本效益的碳源高效生产琥珀酸。

琥珀酸（SA）是一种具有广泛工业用途的有价值的化合物，近年来已成为全球关注的主题。就当前的可持续发展趋势而言，由可再生原料的高效微生物生产者生物基生产 SA 非常重要。在这项研究中，从牛瘤胃中分离出一种新型细菌菌株 LU2，并被认为是一种从乳糖中高效生产 SA 的菌株。进行了蛋白质组学和遗传鉴定以及系统发育分析，菌株 LU2 被归类为产气肠杆菌种。SA 生产的最佳条件是 100 g/L 乳糖、10 g/L 酵母提取物和 20% 接种物，pH 7.0 和 34 °C。在这些条件下，大约 51。当在 3-L 搅拌生物反应器中进行分批发酵时，产生了 35 g/L SA，产率为 53%。当用乳清渗透物代替乳糖时，SA 的最高浓度达到 57.7 g/L，产率和总产率分别为 62% 和 0.34 g/(L*h)。从分批发酵 48 到 72 小时观察到 0.67 g/(L*h) 的最高产率，此时产气大肠杆菌 LU2 产生 16.23 g/L SA。这项研究表明，新分离的产气大肠杆菌 LU2 菌株作为一种从乳清渗透液生产 SA 的新生物催化剂具有巨大潜力。当 E. aerogenes LU2 产生 16.23 g/L SA 时。这项研究表明，新分离的产气大肠杆菌 LU2 菌株作为一种从乳清渗透液生产 SA 的新生物催化剂具有巨大潜力。当 E. aerogenes LU2 产生 16.23 g/L SA 时。这项研究表明，新分离的产气大肠杆菌 LU2 菌株作为一种从乳清渗透液生产 SA 的新生物催化剂具有巨大潜力。