Influence of multiple stresses on the survival and cellar constituent of Tetragenococcus halophilus CGMCC 3792

In this study,the influence ofsingle- stress( acid,heat,or salt) and cross- protection on the survival of Tetragenococcus halophilus CGMCC 3792 was investigated. The results indicated that cells were pre- adapted at p H4.0 or 45 ℃ for 60 min,and then acid challenged at p H2.5 for 60 min,and the survival rate increased 10.6- fold and 8.8- fold,respectively. Analysis of membrane fatty acids and intracellular amino acids in acid- adapted cells showed that unsaturated fatty acids18∶ 1n- 9 and 18 ∶ 2n- 6,9 were 2.3- fold and 2.0- fold higher than that in cells directly subjected to lethal acid stress,respectively. In addition,the intracellular concentrations of glutamate,aspartate,leucine,and isoleucinewere 2.5- fold,2.4- fold,2.2- fold and 2.7- fold higher than those in control cells,respectively. Results presented in this study may contribute to further elucidate the physiological mechanisms employed by T. halophilus during environmental stresses.