| Abstract |
A model of E. coli's responses to marine environmental conditions and resulting cell behaviour has previously been developed. The model considers two kinds of antistress physiological responses and three induced cellular categories with different properties (culturable cells B1, viable but definitively non-culturable cells B2, resuscitable dormant cells B3). Since previous simulations have shown a good correlation with experimental data, we analyse here the effects of some environmental parameters (organic matter, salinity, sunlight) on cellular category dynamics in sea water. Results show that sunlight is the most important factor affecting that dynamics. With the use of two E. coli inocula (log or stationnary phase cells), sanitary implications of the effects of these parameters are evaluated along a river-sea hypothetical gradiant. The fate of reversible dormant B3 cells seems to depend not only on environmental conditions but strongly on the cellular state of the inoculum : stationary phase cells, with which a previously activated antistress response, are less sensitive to environmental stress leads to a high number of dormant cells. If these model previsions are right, it would be highly important to develop suitable methodologies to detect and count in situ such dormant inculturable but resuscitable cells due to their sanitary significance. |
