Escherichia coli: dominance of red light over other visible light sources in establishing viable but nonculturable state.

In this study, the effect of UV-A and different wavelengths of visible light irradiations combined with or without a photosensitizer (methylene blue, MB) on the establishment of viable but nonculturable (VBNC) state in Escherichia coli was investigated. Survival of the E. coli was investigated by measuring plate counts, respiring cell count (RCC), direct viable count (DVC) and total counts over a period of up to 72 h.

Viable but non-culturable state (VBNC) of Escherichia coli related to EnvZ under the effect of pH, starvation and osmotic stress in sea water.

When exposed extreme environmental conditions such as sea water, bacteria have been shown different survival strategy for continue their life. One of this strategy known as viable but nonculturable (VBNC) state which is very important for nondifferiation bacteria. VBNC cells cause serious human health problems.

The effect of starvation stress on the protein profiles in Flexibacter chinensis.

Background: Analysis of many proteins produced during the transition into the stationary phase and under stress conditions (including starvation stress) demonstrated that a number of novel proteins were induced in common to each stress and could be the reason for cross-protection in bacterial cells. It is necessary to investigate the synthesis of these proteins during different stress conditions.

Methods: The changes in protein profile of Flexibacter chinensis at various stages of the starvation process and the other stresses were investigated using two-dimensional gel electrophoresis which has proven to be a powerful tool for investigation of the changes in protein profiles under such conditions.