کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4368444 | 1616667 | 2011 | 7 صفحه PDF | دانلود رایگان |
Tolerance to acid is an important feature for probiotic bacteria during transition through the gastrointestinal tract. Proteomics analysis of a new probiotic bacterium, Lactobacillus casei Zhang, was performed upon 30-min exposure to low acid stress (pH 2.5 vs. pH 6.4) using two-dimensional electrophoresis. Out of 33 protein spots that showed changes of expression between the two pHs, 22 showed 1.5-fold higher expression at pH 2.5 than at pH 6.4, whereas five spots had expression decreased by 1.5-fold at pH 2.5. There were also six protein spots that were exclusively present on different pH maps. Further analysis showed that eight of the enhanced proteins, NagA, NagB, PGM, GlmM, LacC, TDP, GALM and PtsI, were involved in carbohydrate catabolism. Moreover, quantitative RT-PCR showed that the mRNA expression levels of dnaK, nagB, galm, estC, tuf and luxS were consistent with changes in protein expression. We postulate that there might be some relationship between differentially expressed proteins and acid tolerance in L. casei Zhang.
Journal: International Journal of Food Microbiology - Volume 147, Issue 3, 30 June 2011, Pages 181–187