营养胁迫植物乳杆菌KLDS 1.0328的生理特性及其冷冻干燥菌粉贮存稳定性分析

为探究冷冻干燥植物乳杆菌KLDS 1.0328的贮存稳定性受初始营养条件调控的差异性，分析葡萄糖胁迫、吐温80胁迫以及葡萄糖和吐温80复合胁迫对该菌株生长、产酸、细菌素抑菌活性、形态、细胞膜脂肪酸和菌粉贮藏过程中存活率的影响。研究发现，葡萄糖和吐温80胁迫对菌体的生长、产酸和细菌素的产生有不同程度的影响。扫描电镜结果显示，吐温80胁迫或葡萄糖和吐温80复合营养胁迫环境下，菌体由短杆状转变为长棒状或卵圆形，尺寸也随之增大或减小。经多种营养胁迫处理后，各处理组中菌体细胞膜的不饱和脂肪酸与饱和脂肪酸含量比值均有所提高。此外，葡萄糖胁迫可显著提高冷冻干燥植物乳杆菌KLDS 1.0328在－18 ℃贮存42 d期间的稳定性和存活率。

Physiological Characteristics of Nutrient Stressed Lactobacillus plantarum KLDS 1.0328 and Storage Stability of Its Freeze-Dried Cells

In order to investigate the difference in the storage stability of freeze-dried Lactobacillus plantarum KLDS 1.0328 under different nutritional conditions, the effects of glucose and/or Tween-80 stress on the growth, acid production, morphology and cell membrane fatty acid composition of this strain, the antibacterial activity of bacteriocin produced by it, and the survival rate of its freeze-dried cells during frozen storage were analyzed. It was found that both glucose and Tween-80 stress had different impacts on the growth, acid production and bacteriocin antibacterial activity. Scanning electron microscopic (SEM) results indicated that the bacterial cell shape changed from short rod-like to long rod-like or oval-shaped and that the size also changed when exposed to Tween-80 stress or glucose-Tween-80 stress. The ratio of unsaturated fatty acids to saturated fatty acids in the cell membrane increased under all nutrient stress conditions. In addition, the stability and survival rate of freeze-dried cells stored at ?18 ℃ for up to 42 days were significantly improved by glucose stress.