MODELING BACTERIAL-GROWTH OF LACTOBACILLUS-CURVATUS AS A FUNCTION OF ACIDITY AND TEMPERATURE

Models that describe the effect of acidity, temperature, and the combi ned effect of these variables on the growth parameters of Lactobacillu s curvatus are developed and validated. Growth parameters (lag time, s pecific growth fate, and maximum population density) were calculated f rom growth data at different temperature-acidity combinations. Experim ents were set up to assess the quantitative effects of temperature and acidity on the growth parameters rather than for parameter estimation solely. The effect of acidity is monitored at several constant temper ature values. Models are set up and fitted to the. data. The same proc edure is used at constant acidity values to model the effect of temper ature. For lag time, specific growth rate, and maximum population dens ity, the effect of temperature could be multiplied with the effect of acidity tb obtain combinatory models that describe the effect of both controlling factors on the growth parameters. Lag time measurements sh owed large deviations, and therefore the lag time models developed can only. be used to estimate the order of magnitude of lag time.