The effects of temperature, water activity and pH on the growth of Aeromonas hydrophila and on its subsequent survival in microcosm water.
OBJECTIVE
The influence of temperature, water activity and pH on the growth of Aeromonas hydrophila, and on its survival after transfer in nutrient-poor water were assessed.


RESULTS
Experiments were carried out according to a Box-Behnken matrix at 10-30 degrees C, 0.95-0.99 water activity (aw) and pH 5-9. The effect of each factor on the kinetic parameters of growth (i.e. the maximal specific growth rate, mumax, and the lag time, lambda) and on the decline of the bacteria in microcosm water (time to obtain a reduction of 5 log, T5 log) were studied by applying central composite design.


CONCLUSIONS
The major effect of temperature and water activity on the growth of A. hydrophila was highlighted, whereas the effect of pH in these experimental conditions was not significant. Models describing the effect of environmental parameters on the growth of A. hydrophila were proposed. The effect of the growth environment, and particularly the incubation temperature, have an influence on the survival ability of the bacteria in nutrient-poor water.


CONCLUSIONS
The Box-Behnken design was well suited to determine the influence of environmental factors on the growth of A. hydrophila and to investigate the effect of previous growth conditions on its survival in microcosm water.
Sautour
M
M
Laboratoire de Microbiologie, Université des Sciences et Technologies de Lille, Bâtiment, Villeneuve d'Ascq Cedex, France. msautour@hotmail.com
Mary
P
P
Chihib
N E
NE
Hornez
J P
JP
D016980:Aeromonas hydrophila / Q000254:growth & development*; D015169:Colony Count, Microbial; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008954:Models, Biological; D013696:Temperature; D014871:Water Microbiology
D003470:Culture Media