Shen Jie, Du Yuyu, Shen Yuechenfei, Kang Ning, Fan Zhexin, Fang Zhifeng, Yang Bo, Wang Jiancheng, Li Baokun
Key Laboratory of Agricultural Product Processing and Quality Control of Specialty (Co-Construction by Ministry and Province), School of Food Science and Technology, Shihezi University, Shihezi 832000, China.
Key Laboratory for Food Nutrition and Safety Control of Xinjiang Production and Construction Corps, School of Food Science and Technology, Shihezi University, Shihezi 832000, China.
Foods. 2025 Feb 21;14(5):730. doi: 10.3390/foods14050730.
During lactobacillus fermentation, the types of proteins in the fermentation substrate significantly influence the characteristics of the fermented product. Proteins are composed of various amino acids. Consequently, investigating the metabolic mechanisms of key amino acids during lactic acid bacteria fermentation is important for improving their application in the food industry. In this study, the growth of SMN-LBK was significantly inhibited following glutamate and arginine deficiency ( < 0.05). Genomic analysis and in vitro addition assays showed that α-ketoglutarate (OXO), as a precursor of glutamate, significantly eliminated growth inhibition of SMN-LBK ( < 0.05). Meanwhile, the inhibition of SMN-LBK growth following arginine deficiency may be linked to glutamate. Metabolomics analysis illustrated that glutamate and arginine deficiencies mainly affected the carbohydrate and amino acid metabolic pathways of SMN-LBK, especially the pentose phosphate pathway, alanine, glutamate and aspartate metabolism, and arginine metabolism. Transcriptomics analysis further identified glutamate and arginine deficiencies affecting carbohydrate and amino acid metabolism, specifically the glutamate metabolism, pentose phosphate pathway, and glycolysis/gluconeogenesis, involving key genes such as pfkA, gapA, ldh, argG, argE, and argH. Elucidating the molecular mechanisms of key amino acids in SMN-LBK will provide a theoretical foundation for understanding the differential fermentation of various proteins by lactic acid bacteria.
在乳酸菌发酵过程中，发酵底物中的蛋白质类型对发酵产物的特性有显著影响。蛋白质由各种氨基酸组成。因此，研究乳酸菌发酵过程中关键氨基酸的代谢机制对于提高其在食品工业中的应用具有重要意义。在本研究中，谷氨酸和精氨酸缺乏（<0.05）后，SMN-LBK的生长受到显著抑制。基因组分析和体外添加试验表明，α-酮戊二酸（OXO）作为谷氨酸的前体，显著消除了SMN-LBK的生长抑制（<0.05）。同时，精氨酸缺乏后对SMN-LBK生长的抑制可能与谷氨酸有关。代谢组学分析表明，谷氨酸和精氨酸缺乏主要影响SMN-LBK的碳水化合物和氨基酸代谢途径，特别是磷酸戊糖途径、丙氨酸、谷氨酸和天冬氨酸代谢以及精氨酸代谢。转录组学分析进一步确定谷氨酸和精氨酸缺乏影响碳水化合物和氨基酸代谢，特别是谷氨酸代谢、磷酸戊糖途径以及糖酵解/糖异生，涉及pfkA、gapA、ldh、argG、argE和argH等关键基因。阐明SMN-LBK中关键氨基酸的分子机制将为理解乳酸菌对各种蛋白质的差异发酵提供理论基础。
