Zhao Kuo, Gao Hailin, Han Mengnan, Zhang Bo, Liu Zhiqiang, Zou Shuping, Zheng Yuguo
Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014, China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014, China; State Key Laboratory of Green Chemical Synthesis and Conversion, Zhejiang University of Technology, Hangzhou, 310014, PR China.
Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310014, China; Engineering Research Center of Bioconversion and Biopurification of Ministry of Education, Zhejiang University of Technology, Hangzhou, 310014, China; State Key Laboratory of Green Chemical Synthesis and Conversion, Zhejiang University of Technology, Hangzhou, 310014, PR China.
Metab Eng. 2025 Nov;92:161-173. doi: 10.1016/j.ymben.2025.08.003. Epub 2025 Aug 11.
D-pantothenic acid (D-PA) is a vital water-soluble vitamin with diverse industrial applications, driving the demand for efficient microbial production. Here, we rationally engineered an Escherichia coli strain to enhance D-PA production through metabolic engineering. First, to enhance carbon utilization efficiency, competing byproduct pathways were deleted and the pentose phosphate pathway was downregulated. Next, the glucose and β-alanine transport systems were strategically enhanced, and cofactor availability was improved through engineering NADPH regeneration and ATP recycling pathways. Subsequently, pathway engineering was applied to fine-tune the expression of heterologous enzymes, thereby enhancing the metabolic pull toward D-PA biosynthesis. To enhance the supply of one-carbon donor required by the rate-limiting enzyme ketopantoate hydroxymethyltransferase (KPHMT), a heterologous 5,10-methylenetetrahydrofolate biosynthesis module was introduced. Finally, dynamic regulation of isocitrate synthase and pantothenate kinase was implemented to balance cell growth and D-PA production. As a result of the integrated metabolic engineering strategies, the final strain DPZ28/P31 achieved a D-PA titer of 98.6 g/L and a yield of 0.44 g/g glucose in a two-stage fed-batch fermentation. These findings provide valuable insights for industrial-scale production of D-PA and related compounds.
D-泛酸（D-PA）是一种重要的水溶性维生素，具有多种工业应用，推动了对高效微生物生产的需求。在此，我们通过代谢工程合理改造了一株大肠杆菌菌株，以提高D-PA的产量。首先，为提高碳利用效率，删除了竞争性副产物途径并下调了磷酸戊糖途径。接下来，策略性地增强了葡萄糖和β-丙氨酸转运系统，并通过改造NADPH再生和ATP循环途径提高了辅因子的可用性。随后，应用途径工程微调异源酶的表达，从而增强对D-PA生物合成的代谢拉动。为增强限速酶酮泛解酸羟甲基转移酶（KPHMT）所需的一碳供体的供应，引入了一个异源5,10-亚甲基四氢叶酸生物合成模块。最后，实施了异柠檬酸合酶和泛酸激酶的动态调控，以平衡细胞生长和D-PA生产。由于综合代谢工程策略，最终菌株DPZ28/P31在两阶段补料分批发酵中实现了98.6 g/L的D-PA滴度和0.44 g/g葡萄糖的产量。这些发现为D-PA及相关化合物的工业规模生产提供了有价值的见解。
