Estimating growth kinetics of Penicillium chrysogenum by nonlinear regression

A simple unstructured microbial growth model was used to describe the dynam ics of fungal growth in batch cultures. Biokinetic parameters were evaluate d using the integral form of the Contois equation by nonlinear regression. Monte Carlo simulations and sensitivity analyses were performed to evaluate the effectiveness of the nonlinear parameter estimation technique for obta ining unique and accurate estimates of the Contois equation parameters. Thi s technique was subsequently used to estimate growth kinetic parameters of Penicillium chrysogenum grown on glucose. Microbial growth and substrate de pletion were accurately described by the Contois equation and the kinetic p arameters were estimated as mu(max) = 0.103 h(-1), K-c = 0.145 and Y= 0.445 . The applicability of the Contois equation to describe both pellet and fil amentous fungal growth was verified using previously published data. The us e of the integrated Contois equation is advantageous as biokinetic paramete rs can be estimated from a single substrate depletion curve. (C) 1998 Elsev ier Science S.A. All rights reserved.