乳酸盐与渗透胁迫对干酪乳酪杆菌Zhang的损伤机理及保护措施  

Damage Mechanism and Protective Measures of Lactate and Osmotic Stresson Lactobacillus casei Zhang

作　　者：杨雄州 王昊乾 张静雯 黄天 于洁[1] 张和平[1] Yang Xiongzhou;Wang Haoqian;Zhang Jingwen;Huang Tian;Yu Jie;Zhang Heping(Key Laboratory of Dairy Biotechnology and Engineering,Ministry of Education,Key Laboratory of Dairy Products Processing,Ministry of Agriculture and Rural Affairs,Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering,Collaborative Innovative Center of Ministry of Education for Lactic Acid Bacteria and Fermented Dairy Products,Inner Mongolia Agricultural University,Hohhot 010018)

机构地区：[1]内蒙古农业大学、乳品生物技术与工程教育部重点实验室、农业农村部奶制品加工重点实验室、内蒙古自治区乳品生物技术与工程重点实验室、乳酸菌与发酵乳制品省部共建协同创新中心,呼和浩特010018

出　　处：《中国食品学报》2024年第4期108-117,共10页Journal of Chinese Institute Of Food Science and Technology

基　　金：内蒙古自治区科技重大专项(2021ZD0014);国家自然科学基金面上项目(31972054)。

摘　　要：目的:探究乳酸盐与渗透压胁迫对干酪乳酪杆菌Zhang的抑制作用并寻求解决方案。方法:分别使用乳酸钠、乳酸铵与氯化钠对菌体营造有机盐胁迫与渗透压胁迫,测定完全抑制浓度并绘制耐渗透曲线,通过测定菌体密度、活菌数、细胞损伤来观察LCZ受到的生理损伤与相容性溶质的保护效果。通过分批培养与恒定pH分批培养探究渗透压升高的关键因素,通过稀释发酵液以达到降低渗透压的效果,测定稀释后样品菌体密度、活菌数、干重得率的变化。结果:乳酸铵由于自身特性对LCZ具有强烈抑制作用;乳酸钠对LCZ的抑制作用较为温和,对LCZ起到的主要抑制作用是高渗抑制。L-脯氨酸对高渗环境下LCZ生物量积累及细胞活性均有显著保护作用,最优添加量为2 g/L。稀释发酵液处理对恒定pH补料培养菌体密度与活菌数的提升效果显著,最终发酵液OD_(600nm)与活菌数可达到19.68±0.429与(3.439±0.110)×10^(10)CFU/mL,分别是未稀释处理的1.61倍与1.46倍。结论:L-脯氨酸能够在一定程度上缓解高渗下LCZ的活性损伤。通过稀释发酵液处理降低发酵后期渗透压,能极大地提升发酵水平及细胞活性,研究结果为工业化生产及应用提供参考。Objective:To investigate the inhibitory effects of lactate and osmotic stress on Lactobacillus casei Zhang and to find solutions.Methods:The organic salt stress and osmotic pressure stress were created by using sodium lactate,ammonium lactate and sodium chloride,respectively,to determine the concentration of complete inhibition and plot the osmotic resistance curve,and the physiological damage to LCZ and the protective effect of compatible solutes were observed by measuring the density of the bacteria,the number of viable bacteria and cell damage.The key factors of osmotic pressure elevation were explored by batch culture and constant pH batch culture,and the effect of osmotic pressure reduction was achieved by diluting the fermentation broth,and the changes of bacterial density,viable bacterial count and dry weight yield of the samples were measured after dilution.Results:L-proline has a significant protective effect on LCZ biomass accumulation and cell activity under hypertonic environment,and the optimal addition amount is 2 g/L.The diluted fermentation broth treatment has a significant effect on the density and viable count of bacteria in constant pH supplemented culture.The final fermentation broth OD_(600nm) and viable bacteria count could reach 19.68±0.429 and(3.439±0.110)×10^(10) CFU/mL,which were 1.61 and 1.46 times of the undiluted treatment,respectively.Conclusion:L-proline can alleviate the activity damage of LCZ under hypertonicity to a certain extent,and reducing the osmotic pressure at the later stage of fermentation by diluting the fermentation broth treatment can greatly improve the fermentation level and cell activity,which can provide reference for industrial production and application.

关 键 词：干酪乳酪杆菌Zhang 乳酸盐胁迫 渗透胁迫 相容性溶质 高密度发酵 

分 类 号：TS201.3[轻工技术与工程—食品科学]