中文摘要：

以（Lactobacillus plantarum D5-5）为研究对象,用不同体积分数乙醇胁迫菌体,测定乙醇胁迫后菌体中乳酸脱氢酶（LDH）、ATP酶的活力,胞外β-半乳糖苷酶相对酶活及细胞膜特性的变化,分析乙醇胁迫后造成菌体失活的主要因素,探讨乙醇胁迫对乳酸杆菌的损伤机制。结果表明：在乙醇体积分数为6%~8%胁迫条件下,菌体存活率分别降低了44.07%、61.81%、69.79%,乙醇胁迫对植物乳杆菌D5-5LDH、ATP酶具有显著影响,胞外β-半乳糖苷酶相对酶活升高,细胞膜完整性和表面结构受破坏程度增强。说明LDH、ATP酶是影响乙醇胁迫损伤的关键酶,乙醇胁迫致使菌体关键酶失活,细胞膜完整性破坏,细胞表面结构受损,从而影响植物乳杆菌D5-5的正常生理代谢。

英文摘要：

To analyze the main factors causing the loss of viability and the physiological damage mechanism of Lactobacillus plantarum D5-5,in this study,the survival rates of bacteria was investigated during different treatments concentrations of ethanol. In addition,the activity changes of lactate dehydrogenase（LDH）,ATPases,the extracellular relative β-galactosidase and the cell membrane with stress treatments were determined relatively. The results showed that the survival rate of Lactobacillus plantarum D5-5 was decreased by 44.07%、61.81%、69.79% with 6%~8%ethanol concentration treatments,and the activities of LDH and ATPase were significantly affected,but the extracellular relative β-galactosidase activity was increased. Meanwhile,the membrane integrity and cell ultrastructure was injured in the presence of ethanol stress treatment. The above results indicated that LDH and ATPase are the key enzymes resulting the activity loss by ethanol stress and could be used to evaluate the effect of ethanol stress on viability and metabolic activities of Lactobacillus plantarum D5-5 during different treatments concentrations of ethanol.