Raethong Nachon, Chamtim Pitakthai, Thananusak Roypim, Whanmek Kanyawee, Santivarangkna Chalat
Institute of Nutrition, Mahidol University, Nakhon Pathom, 73170, Thailand.
Academic Service Division, National Laboratory Animal Center, Mahidol University, Nakhon Pathom, 73170, Thailand.
Heliyon. 2025 Jan 10;11(2):e41879. doi: 10.1016/j.heliyon.2025.e41879. eCollection 2025 Jan 30.
GABA-producing probiotics present promising opportunities for developing functional foods. Carbon sources have been identified as a critical influence on GABA production. Therefore, this study investigated the holistic metabolic responses and GABA biosynthesis to various carbon sources of 9D3, a proficient GABA producer, using a genome-wide transcriptomic approach. The analysis revealed 414 genes with differential expression responses to altering carbon sources, i.e., glucose, sucrose, and lactose, notably sugar phosphotransferase systems (PTS) (11 genes), indicating carbon source-mediated transcriptional change patterns in 9D3. The integration of transcriptome data with a genome-scale metabolic network (GSMN) revealed that 9D3 displays adaptability by synthesizing GABA as an alternative acid-tolerant mechanism when lactose is used as a carbon source rather than depending on the fatty acid synthesis and the arginine catabolic pathway. The findings of this study offer valuable insights into optimal carbon source utilization and gene expression co-regulation, thereby enhancing the GABA-producing capability of a probiotic and broadening its potential applications in the functional food industry.
产生γ-氨基丁酸（GABA）的益生菌为开发功能性食品提供了广阔的机遇。已确定碳源是影响GABA产生的关键因素。因此，本研究采用全基因组转录组学方法，研究了高效GABA生产者9D3对各种碳源（葡萄糖、蔗糖和乳糖）的整体代谢反应和GABA生物合成。分析揭示了414个对碳源变化（即葡萄糖、蔗糖和乳糖）有差异表达反应的基因，特别是糖磷酸转移酶系统（PTS）（11个基因），表明9D3中存在碳源介导的转录变化模式。转录组数据与基因组规模代谢网络（GSMN）的整合表明，当乳糖用作碳源时，9D3通过合成GABA作为一种替代的耐酸机制来显示适应性，而不是依赖脂肪酸合成和精氨酸分解代谢途径。本研究结果为最佳碳源利用和基因表达共调控提供了有价值的见解，从而提高了益生菌产生GABA的能力，并拓宽了其在功能性食品工业中的潜在应用。
