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Choosing probability distributions for modelling generation time variability


Ratkowsky, DA and Ross, T and Macario, N and Dommett, TW and Kamperman, LT, Choosing probability distributions for modelling generation time variability, Journal of Applied Bacteriology, 80, (2) pp. 131-137. ISSN 0021-8847 (1996) [Refereed Article]

DOI: doi:10.1111/j.1365-2672.1996.tb03200.x


This paper explores the variation in generation time of bacterial systems growing at suboptimal temperatures. Generation time generally has a distribution with a long right-hand tail, suggesting a model with variance proportional to the second or third power of its mean. Suitable non-normal probability distributions include the 'gamma' and 'inverse Gaussian', with the modelling being carried out by 'generalized linear regression'. The procedure is illustrated with replicated data on Pseudomonas fluorescens obtained using a gradient temperature incubator with nutrient broth as the growth medium. The results show that the 'gamma' distribution is a suitable stochastic assumption when modelling generation time. This enables one to predict, for example, a mean generation time of 615 min at 2.4°C, and that 0.1% of the observed values will fall below 471 min and one in a million below 405 min. Use of an unreplicated set of data gave less conclusive results but favoured the 'inverse Gaussian' distribution as the stochastic model.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Microbiology
Research Field:Bacteriology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the environmental sciences
UTAS Author:Ratkowsky, DA (Dr David Ratkowsky)
UTAS Author:Ross, T (Professor Tom Ross)
UTAS Author:Kamperman, LT (Ms Laura Taliaco Kamperman)
ID Code:7036
Year Published:1996
Web of Science® Times Cited:33
Deposited By:Agricultural Science
Deposited On:1996-08-01
Last Modified:2011-08-16

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