Cheng Yichao, Wang Xinyi, Wu Di, Lu Yao, Qin Yi, Liu Yanlin, Liang Yanying, Song Yuyang
College of Enology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Ningxia Helan Mountain's East Foothill Wine Experiment and Demonstration Station of Northwest, A&F University, Yongning, 750104, Ningxia, China.
Appl Microbiol Biotechnol. 2025 Sep 16;109(1):203. doi: 10.1007/s00253-025-13590-3.
Pichia kudriavzevii is a widely used yeast in the wine industry that can degrade citric acid. However, this process can be hindered by the presence of glucose through a phenomenon called carbon catabolite repression (CCR). Herein, this study determined the underlying mechanism by examining the effects of glucose on P. kudriavzevii. Our findings indicated that glucose inhibited the reduction of citric acid and maintained elevated levels of fatty acids and glycerophospholipids. However, the inhibition of citric acid degradation under glucose addition was related to the retarded accumulation of metabolites involved in the biosynthesis of antibiotics, propanoate metabolism, microbial metabolism in diverse environments, C5-branched dibasic acid metabolism, and metabolic pathways in diverse environments. Additionally, the integrated data revealed that citrate catabolism of P. kudriavzevii was remarkably repressed in response to glucose by regulating glycerophospholipid metabolism, carbon metabolism and the biosynthesis pathways of secondary metabolites. Further investigations indicated that the increase of fatty acids (e.g., alpha-linolenic and arachidic) and glycerophospholipids (e.g., dihydroxyacetone phosphate and glycerophosphocholine) under glucose addition was related to the up-regulated GPD1, PISD, HIS1 and RPIA gene expressions in glycerophospholipid metabolism and the down-regulated FBP1, MDH, IDH3, ICL1, ACL and JEN1 gene expressions in carbon metabolism and the biosynthesis pathways of secondary metabolites. Meantime, glucose regulated the expression of transcription factors (e.g., MIG1 and GCN4) associated with three pathways, which were crucial genes of CCR regulatory networks. Overall, we uncovered the metabolic regulatory network through which CCR inhibits citric acid utilization in P. kudriavzevii. KEY POINTS: • Metabolic changes of P. kudriavzevii cells responding to carbon sources were observed • Potential genes regulating citric acid degradation contributing to CCR were screened • The inhibition of citric acid degradation is due to changes in the regulatory network.
季也蒙毕赤酵母是葡萄酒行业中广泛使用的一种酵母，能够降解柠檬酸。然而，通过一种称为碳分解代谢物阻遏（CCR）的现象，葡萄糖的存在会阻碍这一过程。在此，本研究通过考察葡萄糖对季也蒙毕赤酵母的影响来确定其潜在机制。我们的研究结果表明，葡萄糖抑制了柠檬酸的减少，并使脂肪酸和甘油磷脂水平维持在较高水平。然而，添加葡萄糖时柠檬酸降解的抑制与抗生素生物合成、丙酸代谢、不同环境中的微生物代谢、C5-支链二元酸代谢以及不同环境中的代谢途径所涉及的代谢物积累延迟有关。此外，整合数据显示，通过调节甘油磷脂代谢、碳代谢和次生代谢物生物合成途径，季也蒙毕赤酵母的柠檬酸分解代谢在响应葡萄糖时受到显著抑制。进一步研究表明，添加葡萄糖时脂肪酸（如α-亚麻酸和花生酸）和甘油磷脂（如磷酸二羟丙酮和甘油磷酸胆碱）的增加与甘油磷脂代谢中GPD1、PISD、HIS1和RPIA基因表达上调以及碳代谢和次生代谢物生物合成途径中FBP1、MDH、IDH3、ICL1、ACL和JEN1基因表达下调有关。同时，葡萄糖调节了与这三条途径相关的转录因子（如MIG1和GCN4）的表达，这些转录因子是CCR调控网络的关键基因。总体而言，我们揭示了CCR抑制季也蒙毕赤酵母利用柠檬酸的代谢调控网络。要点：•观察到季也蒙毕赤酵母细胞对碳源的代谢变化•筛选出有助于CCR的调节柠檬酸降解的潜在基因•柠檬酸降解的抑制是由于调控网络的变化
