TORC1途径调控发酵香肠合成菌群代谢产物cross-feeding促进乳酸菌合成GABA的机制

发酵香肠工业化加工存在的技术瓶颈之一是加工过程中无法在稳定保持食用品质的前提下保障典型营养物质含量，例如：γ-氨基丁酸（GABA）等兼具呈味和功能活性的代谢产物，其原因在于发酵香肠加工过程中核心菌种代谢互作协同调控关键风味和代谢产物形成的机制尚未揭示清楚。项目前期构建了能够产出发酵香肠典型风味和GABA的合成菌群，该菌群中酵母菌分泌的代谢物可促进乳酸菌合成GABA，但具体分子机制尚不清楚。本项目拟采用基因组规模代谢模型预测，培养组学、代谢组学、代谢动力学验证的策略，明确乳酸菌和酵母菌代谢产物cross-feeding合成GABA必须的氨基酸及其流向；通过解析酵母菌TORC1、NCR基因调控种间代谢产物cross-feeding的具体途径，阐明TORC1途径调控发酵香肠合成菌群代谢产物cross-feeding促进乳酸菌合成GABA的分子机制，这对风味营养兼备型肉制品的研发具有重要意义。

One of the technical bottlenecks in the commercial process of fermentation sausage is the inability of core strains to stably maintain both the flavor and content of functional metabolites, such as γ-aminobutyric acid (GABA), which contribute both flavor and nutrition. The main reason for this is that interactions between metabolic processes in core strains used in meat product fermentation that synergistically regulate the production of key metabolites contributing to flavor and function are not yet clearly understood. In the early stage of this project, we established the synthetic microbiota used to produce typical fermented sausage flavors and γ-aminobutyric acid (GABA). We found a metabolite cross-feeding pattern between lactic acid bacteria and yeast in this synthesized flora. Yeast effectively promoted GABA synthesis by lactic acid bacteria. However, the molecular mechanisms are still unclear. Thus, this project aims to investigate the metabolites and cross-feeding patterns between lactic acid bacteria and yeast that synergistically promote GABA synthesis, using a genome-scale community metabolic model predicts amino acid cross-feeding, exo-metabolome dynamics reveals multi-component cross-feeding, and to analyze the involvement of the TORC1 pathway and NCR genes in this synergistic promotion of GABA synthesis, to improve the molecular understanding of TORC1 pathway regulates metabolites cross-feeding from the synthetic microbiota of fermented sausage to promote GABA synthesis by lactic acid bacteria, which can guide research and development of meat products that can maximize flavor as well as nutrition.