Abstract
Models that describe the effect of acidity, temperature, and the combined effect of these variables on the growth parameters of Lactobacillus curvatus are developed and validated. Growth parameters (lag time, specific growth rate, and maximum population density) were calculated from growth data at different temperature-acidity combinations. Experiments 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 temperature values. Models are set up and fitted to the data. The same procedure is used at constant acidity values to model the effect of temperature. For lag time, specific growth rate, and maximum population density, the effect of temperature could be multiplied with the effect of acidity to obtain combinatory models that describe the effect of both controlling factors on the growth parameters. Lag time measurements showed large deviations, and therefore the lag time models developed can only be used to estimate the order of magnitude of lag time.
Full Text
The Full Text of this article is available as a PDF (259.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Adams M. R., Little C. L., Easter M. C. Modelling the effect of pH, acidulant and temperature on the growth rate of Yersinia enterocolitica. J Appl Bacteriol. 1991 Jul;71(1):65–71. [PubMed] [Google Scholar]
- McMeekin T. A., Chandler R. E., Doe P. E., Garland C. D., Olley J., Putro S., Ratkowsky D. A. Model for combined effect of temperature and salt concentration/water activity on the growth rate of Staphylococcus xylosus. J Appl Bacteriol. 1987 Jun;62(6):543–550. doi: 10.1111/j.1365-2672.1987.tb02687.x. [DOI] [PubMed] [Google Scholar]
- Ratkowsky D. A., Lowry R. K., McMeekin T. A., Stokes A. N., Chandler R. E. Model for bacterial culture growth rate throughout the entire biokinetic temperature range. J Bacteriol. 1983 Jun;154(3):1222–1226. doi: 10.1128/jb.154.3.1222-1226.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sutherland J. P., Bayliss A. J., Roberts T. A. Predictive modelling of growth of Staphylococcus aureus: the effects of temperature, pH and sodium chloride. Int J Food Microbiol. 1994 Feb;21(3):217–236. doi: 10.1016/0168-1605(94)90029-9. [DOI] [PubMed] [Google Scholar]
- Wijtzes T., McClure P. J., Zwietering M. H., Roberts T. A. Modelling bacterial growth of Listeria monocytogenes as a function of water activity, pH and temperature. Int J Food Microbiol. 1993 Apr;18(2):139–149. doi: 10.1016/0168-1605(93)90218-6. [DOI] [PubMed] [Google Scholar]
- Zwietering M. H., Cuppers H. G., de Wit J. C., van 't Riet K. Evaluation of data transformations and validation of a model for the effect of temperature on bacterial growth. Appl Environ Microbiol. 1994 Jan;60(1):195–203. doi: 10.1128/aem.60.1.195-203.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zwietering M. H., Jongenburger I., Rombouts F. M., van 't Riet K. Modeling of the bacterial growth curve. Appl Environ Microbiol. 1990 Jun;56(6):1875–1881. doi: 10.1128/aem.56.6.1875-1881.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]