Meng Qiang, Li Yueyao, Yuan Yuxin, Wu Shaowen, Shi Kan, Liu Shuwen
College of Enology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Shaanxi Engineering Research Center for Viti-Viniculture, Yangling, 712100, Shaanxi, China.
Stress Biol. 2022 Nov 14;2(1):48. doi: 10.1007/s44154-022-00072-z.
This paper reported a wine-derived lactic acid bacterium, Lactiplantibacillus plantarum XJ25, which exhibited higher cell viability under acid stress upon methionine supplementation. Cellular morphology and the composition of the cytomembrane phospholipids revealed a more solid membrane architecture presented in the acid-stressed cells treated with methionine supplementation. Transcriptional analysis showed L. plantarum XJ25 reduced methionine transport and homocysteine biosynthesis under acid stress. Subsequent overexpression assays proved that methionine supplementation could alleviate the cell toxicity from homocysteine accumulation under acid stress. Finally, L. plantarum XJ25 employed energy allocation strategy to response environmental changes by balancing the uptake methionine and adjusting saturated fatty acids (SFAs) in membrane. These data support a novel mechanism of acid resistance involving methionine utilization and cellular energy distribution in LAB and provide crucial theoretical clues for the mechanisms of acid resistance in other bacteria.
本文报道了一种源自葡萄酒的乳酸菌——植物乳杆菌XJ25，在补充蛋氨酸后，该菌在酸胁迫下表现出更高的细胞活力。细胞形态和细胞膜磷脂组成显示，补充蛋氨酸处理的酸胁迫细胞呈现出更致密的膜结构。转录分析表明，植物乳杆菌XJ25在酸胁迫下减少了蛋氨酸转运和同型半胱氨酸生物合成。随后的过表达试验证明，补充蛋氨酸可以减轻酸胁迫下同型半胱氨酸积累带来的细胞毒性。最后，植物乳杆菌XJ25采用能量分配策略，通过平衡蛋氨酸摄取和调节膜中饱和脂肪酸（SFA）来应对环境变化。这些数据支持了乳酸菌中一种涉及蛋氨酸利用和细胞能量分布的新型抗酸机制，并为其他细菌的抗酸机制提供了关键的理论线索。
