Effect of Ethanol Stress on the Metabolic Activity of Lactobacillus plantarum D5-5

Abstract:

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.