Model for combined effect of temperature and salt concentration/water activity on the growth rate of Staphylococcus xylosus

• Published in: Journal of applied bacteriology Vol. 62; no. 6; pp. 543 - 550
• Main Authors: McMeekin, T. A, Chandler, R. E, Doe, P. E, Garland, C. D, Olley, June, Putro, S, Ratkowsky, D. A
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.06.1987
• Subjects: Animals; equations; Kinetics; Mathematics; microbiology; Models, Biological; Regression Analysis; salt concentration; salt tolerance; sodium chloride; Sodium Chloride - pharmacology; Staphylococcus - growth & development; Staphylococcus xylosus; Temperature; water activity; Water Microbiology
• ISSN: 1364-5072; 0021-8847; 1365-2672
• DOI: 10.1111/j.1365-2672.1987.tb02687.x

The combined effect of temperature and NaCl concentration/water activity on the growth rate of a strain of halotolerant Staphylococcus is described by the squareroot models which had been used previously to model temperature dependence only. The model r=b(T ‐ Tmin) is shown to be a special case of the BélehraAdek temperature function which is given by r=a(T ‐ aL)d. The constant aL is the so‐called ‘biological zero’ and equivalent to Tmin in the square‐root models. This and the exponent d= 2 were unaffected by changing NaCl concentration/water activity. The Bélehradek‐type equations are preferable to the Arrhenius equation in that their parameters do not change with temperature. The constancy of Tmin allows derivation of a simple expression relating growth rate of strain CM21/3 to temperature and salt concentration/water activity within the range of linear response to temperature predicted by the square‐root model.