Zhu Zirong, Cao Li, Xia Ziyuan, Liu Xirong, Chen Wangqion, Dai Zirui, Jin Duo, Rang Jie, Hu Shengbiao, Xia Liqiu
College of Life Science, Hunan Normal University, Hunan Provincial Key Laboratory of Microbial Molecular Biology, Changsha, 410081, Hunan, China.
Hunan Norchem Pharmaceutical Co., Ltd, Changsha, Hunan, 410205, China.
Synth Syst Biotechnol. 2025 Feb 20;10(2):583-592. doi: 10.1016/j.synbio.2025.02.010. eCollection 2025 Jun.
Microorganisms are often likened to complex production workshops. In (), the biosynthesis of spinosad is a production line within its intricate workshop. Optimizing the entire production environment and reducing unnecessary metabolic flow is essential to increasing spinosad yield. Pyruvate serves as a crucial precursor for spinosad biosynthesis. Previous studies revealed that the gene is highly expressed in the gluconeogenic pathway, leading to a pyruvate shunt. By downregulating , we enhanced spinosad yield, although the improvement was below expectations. We speculated that most of the accumulated pyruvate following the knockdown entered some synthetic pathways unrelated to spinosad. Through metabolic pathway and qRT-PCR analyses, we found that the expression levels of and within the pyruvate metabolic tributary, including the TCA cycle and ethylmalonyl-CoA pathway, were significantly increased in the knockdown strain. The combined knockdown of these three genes optimized the spinosad production line, increasing its yield to 633.1 ± 38.6 mg/L, representing a 199.4 % increase. This study identifies three key genes for optimizing spinosad biosynthesis and offers insights into gene screening and the efficient construction of Spinosad-producing strains.
微生物常被比作复杂的生产车间。在（）中，多杀菌素的生物合成是其错综复杂的车间内的一条生产线。优化整个生产环境并减少不必要的代谢流对于提高多杀菌素产量至关重要。丙酮酸是多杀菌素生物合成的关键前体。先前的研究表明，（）基因在糖异生途径中高度表达，导致丙酮酸分流。通过下调（），我们提高了多杀菌素产量，尽管改善程度低于预期。我们推测，（）基因敲低后积累的大部分丙酮酸进入了一些与多杀菌素无关的合成途径。通过代谢途径和qRT-PCR分析，我们发现，在（）基因敲低菌株中，丙酮酸代谢支流（包括三羧酸循环和乙基丙二酰辅酶A途径）内的（）和（）的表达水平显著增加。这三个基因的联合敲低优化了多杀菌素生产线，使其产量提高到633.1±38.6mg/L，增幅为199.4%。本研究确定了优化多杀菌素生物合成的三个关键基因，并为基因筛选和高效构建多杀菌素生产菌株提供了见解。
