Browsing by Author "Thibault, J"

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    A neural network estimator for total biomass of filamentous fungi growing on two dimensional solid substrate
    (KLUWER ACADEMIC PUBL, 1998) Acuna, G; Giral, R; Agosin, E; Jorquera, H; Perez Correa, R; Ferret, E; Molin, P; Thibault, J
    A neural network dynamic model is proposed for the on-line estimation of total biomass during filamentous fungi cultures on two dimensional solid substrate. The neural network provides an accurate and robust estimation of biomass from macroscopic measurements of the colony radius evolution. Experiments were performed on Gibberella fujikuroi growing on Petri dishes under different conditions of temperature and water activity.
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    Reassessment of the estimation of dissolved oxygen concentration profile and K(L)a in solid-state fermentation
    (ELSEVIER SCI LTD, 2000) Thibault, J; Pouliot, K; Agosin, E; Perez Correa, R
    Oxygen mass transfer in aerobic microbial growth systems is often a limiting factor for optimal growth and productivity. Oxygen mass transfer has been widely studied in submerged fermentations but has attracted as yet little attention for solid state fermentations. The parallel to submerged fermentation has led to the incorrect interpretation and use of the overall oxygen mass transfer coefficient (K(L)a) to assess the ability of a particular fermentation system to supply the oxygen to microorganisms. The use of K(L)a, as traditionally defined, should be used with caution in solid substrate fermentation systems because there is no convection on the liquid side of the medium, and oxygen is consumed in the biofilm. Hence, K(L)a must be redefined for solid state fermentation. In this payer, the use of oxygen mass transfer coefficients in solid state fermentations is clarified. Published literature data were analysed with a simple pseudo-steady-state model and used to discuss the influence of the biofilm thickness, the dissolved oxygen diffusion coefficient, the convective gas mass transfer coefficient, and the gas flow rate on the oxygen mass transfer coefficient in solid state fermentations. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.