AN EXAMPLE OF THE STAGES IN THE DEVELOPMENT OF A PREDICTIVE MATHEMATICAL-MODEL FOR MICROBIAL-GROWTH - THE EFFECTS OF NACL, PH AND TEMPERATURE ON THE GROWTH OF AEROMONAS-HYDROPHILA
Pj. Mcclure et al., AN EXAMPLE OF THE STAGES IN THE DEVELOPMENT OF A PREDICTIVE MATHEMATICAL-MODEL FOR MICROBIAL-GROWTH - THE EFFECTS OF NACL, PH AND TEMPERATURE ON THE GROWTH OF AEROMONAS-HYDROPHILA, International journal of food microbiology, 23(3-4), 1994, pp. 359-375
The stages involved in developing a predictive model are illustrated u
sing data describing the effects of temperature (3-20-degrees-C), NaCl
concentration (0.5-4.5% w/v) and pH (4.6-7.0) on the aerobic growth o
f Aeromonas hydrophila (cocktail of 6 strains). Optical density measur
ements using micro-titre plates were used as an initial scree, to dete
rmine the appropriate sampling times for viable counts to be made and
to determine the approximate boundaries for growth. Growth curves were
generated from viable counts and fitted using a modified Gompertz equ
ation. Quadratic response surface equations were fitted to the log of
lag and generation times, in response to the variables of temperature,
NaCl and pH (in terms of hydrogen ion concentration). The effects of
various combinations of these controlling factors are described. Compa
risons between predicted growth rates and lag times from our response
surface equations and other models for growth of A. hydrophila, develo
ped with viable count data and optical density measurements, are made,
together with comparisons with data from the literature on the growth
of this bacterium in foods.