Computing and Interpreting Specific Production Rates in a Chemostat in Steady State According to the Luedeking-Piret model

Abstract

The Luedeking-Piret model is an empirical relationship which is very widely used in cell cultures to evaluate specific production rates of some products (metabolites or others). It constitutes a very common method of calculation as much in fundamental as in applied research and especially for designing and optimizing industrial processes in very varied fields. However, this model appears to be frequently deficient and has to be greatly adapted, practically, one might say, for each individual case. Obviously, this is a very great drawback, requiring a great deal of time spent on it and one that greatly lessens the 'universality' of the model. This work reveals that it is possible to give the initial Luedeking-Piret model a much more general scope. The used method revealed metabolic switches that have never been suspected until now. Confirmation of the method would certainly give a precious general tool both to optimize production processes and to increase understanding of some physiological states of cells in chemostat.

Medium Optimization and Fermentation Kinetics for κ-Carrageenase Production by Thalassospira sp. Fjfst-332

“…The Luedeking–Piret equation is a nonlinear regression equation used to simulate the relationship between bacterial growth concentration and product formation [23]. The verification test was carried out at optimal medium (fermentation conditions 125 r/min, 25 °C, and 3 mL inoculum size), and preliminary analysis was performed on the batch pattern owing to the growth type (II).…”

Effect of pH and dilution rate on specific production rate of extra cellular metabolites by Lactobacillus salivarius UCO_979C in continuous culture

“…The specific production of lactic acid did not show a trend of Luedeking-Piret type, and indeed, other authors have already stated that this may happen (Thierie 2013) and that adjusted models correspond to quadratic type models.…”

“…However, there is evidence of loss of linearity in the trends of the specific production rates, commonly called adaptations from Luedeking-Piret equation (Thierie 2013). The phenomena associated with non-linearity in the specific rate are related to the limitation and substrate inhibition (Rogers et al 1978;Jorgensen and Nikolajsen 1987;Berry et al 1999) or to the presence of inhibit or agents (Ohara et al 1992;Pinelli et al 1997).…”

Impacts of different concentrations of Copper and Zinc on in vitro responses of Azotobacter chroococum in biomass and nitrogen fixing outputs

“…Since, α > 0 and β > 0, then it implies that in this trial, nitrogen fixation was associated with both biomass growth and biomass concentration of A. chroococum (Ramakrishnan et al, 2015). However, since β (0.14032) is far greater than α (0.0010156), and also since the value of α = 0.0010156 is not significant at 0.01 level of significance, one may infer that nitrogen fixation yields in these trials were more significantly influenced by the non-growth associated constant (β), or otherwise insignificantly determined by the growth associated constant, α (Ahmad et al, 2011;Thierie, 2013). A linear regression plot of nitrogen fixation rate against specific growth rate for zinc trials gave α = -0.00054363 and β = 0.15508 (Figure 4).…”