Influence of culture conditions on acid tolerance of Lactobacillus casei YIT 9018 = 배양조건에 따른 Lactobacillus casei YIT 9018 의 내산성 변화

Abstract

We studied the influence of culture conditions on the acid tolerance of Lactobacillus casei YIT 9018 in artificial gastric juice with respect to relative amount of membrane bound ATPase and their biochemical characteristics. With raising incubation temperature from 30.5℃ to 40.5℃ and lengthening incubation tine from exponential phase to late stationary phase, the acid tolerance of L. casei YIT 9018 was increased. As acid tolerance enhanced, C_(18:1) content of membrane fatty acid was reduced and C_(l9:0 cyclo) was enriched but the others were not changed greatly. At high ATPase activity, proton permeability was relatively low but this phenomenon did not correspond to acid tolerance. In conclusion, it was considered that changes of C_(18:1) and C_(19:0 cyclo) were closely related to the acid tolerance of L. casei YIT 9018.