Wang Shuxian

Susceptibility of a Vibrio alginolyticus rpoS mutant to environmental stresses and its expression of OMPs

Vibrio alginolyticus, one of the most important opportunistic pathogens, can be detected in human being and marine animals. Like other bacteria, V. alginolyticus is able to adapt to a variety of stressful environmental changes. The alternate sigma factor RpoS, which is a regulator during stationary phase, plays an important role in surviving under these stressful situations in many bacteria. Sequence analysis reveals a 990 bp open reading frame which is predicted to encode a 330‐amino‐acid protein with 68% to 96% overall identity to other reported sequences. To study the function of rpoS, the rpoS gene of V. alginolyticus VIB283 was cloned and an rpoS mutant was constructed by homologous recombination. Comparison of the study result of the wild type and the mutant showed that the mutant was more sensitive to stress conditions such as high osmolarity, oxidative stress, heat shock, and long‐term starvation and that the LD50 of the mutant strain to the zebra fish was about 2.8 times as that of the control strain. In addition, the SDS‐PAGE analysis indicated that the outer membrane proteins (OMPs) existed great differences. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)