Mechanistic modelling of the inhibitory effect of pH on microbial growth. (June 2018)

• Record Type: Journal Article
• Authors: Akkermans, Simen; Van Impe, Jan F.
• Is Part Of: Food microbiology. Volume 72(2018)
• Page Start: 214
• Page End: 219
• Publication Date: 2018-06
• Subjects: Predictive microbiology -- Mechanistic model -- Gamma concept -- Product inhibition; Food Microbiology -- Periodicals; Aliments -- Microbiologie -- Périodiques; Food -- Microbiology; Periodicals; Food -- Microbiology -- Periodicals; Food contamination -- Periodicals; 664.001579
• DOI: 10.1016/j.fm.2017.12.007
• Languages: English
• ISSNs: 0740-0020

Abstract

Abstract: Modelling and simulation of microbial dynamics as a function of processing, transportation and storage conditions is a useful tool to improve microbial food safety and quality. The goal of this research is to improve an existing methodology for building mechanistic predictive models based on the environmental conditions. The effect of environmental conditions on microbial dynamics is often described by combining the separate effects in a multiplicative way (gamma concept). This idea was extended further in this work by including the effects of the lag and stationary growth phases on microbial growth rate as independent gamma factors. A mechanistic description of the stationary phase as a function of pH was included, based on a novel class of models that consider product inhibition. Experimental results on Escherichia coli growth dynamics indicated that also the parameters of the product inhibition equations can be modelled with the gamma approach. This work has extended a modelling methodology, resulting in predictive models that are (i) mechanistically inspired, (ii) easily identifiable with a limited work load and (iii) easily extended to additional environmental conditions. Highlights: Application of a primary model with a mechanistic description of the stationary phase. Inclusion of the pH effect in a mechanistic model based on the gamma concept. Bioreactor experiments to study the effect of pH on the growth of E. coli K12.