Stress Resistance Mechanism of Lactobacillus fermentum CJS101 with Unusually High Resistance to Various Environmental Stresses

초록

In previous studies 108 vaginal Lactobaillus spp. were isolated from Korean and several strains which showed high antimicrobial activity, high detergent MIC, antibiotics MIC1) were selected.2) In this study Lactobaillus sp. CJS101 which showed high resistance to various environmental stresses was selected for further study. CJS101 was identified as L. fermentum using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) and 16S rDNA sequencing. Morphological changes after being exposed to various stresses were observed using scanning electron microscopy. As a result, CJS101 maintained high viability with morphological changes. In order to determine the mechanism of stress resistance at the molecular level we attempted to clone rpoE gene from CJS101. Initially we cloned partial rpoE (directed RNA polymerase, delta subunit) using degenerate primers. RpoE has been known to play a role in adaptation to environmental stress and the cellular morphology in other bacterium during growth3). The cloned rpoE of CJS101 is similar to that of the directed RNA polymerase, delta subunit of Lactobacillus plantarum, Listeria monocytogenes EGD-e, displaying sequence identity of 68%, and 64%, respectively. Attempts are being made for full sequencing the rpoE using single primer PCR as well as for comparing protein expression profile between stressed cell and unstressed cell.