Browsing by Author "Ferret, E"

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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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    Macroscopic growth of filamentous fungi on solid substrate explained by a microscopic approach
    (JOHN WILEY & SONS INC, 1999) Ferret, E; Simeon, JH; Molin, P; Jorquera, H; Acuna, G; Giral, R
    A quantitative model predicting biomass growth an solid media has been developed. The model takes into account steric interactions between hyphae and tips at the microscopic level (competition for substrate and tip-hypha collisions), These interactions effect a slowing down of the hyphal, population-averaged extension rate and are responsible, at the microscopic level, for the distribution of tip orientations observed at the colony border. At the macroscopic level, a limiting value of the colony radial extension rate is attained. A mathematical model that combines hyphal branching, tip diffusion, and biomass growth was proposed to explain such behavior. Experiments using Gibberella fujikuroi were performed to validate the model; good agreement between experiments and simulations was achieved. Most parameters can be measured by simple image analysis on the peripheral growth zone, and they have clear physical meaning; that is, they correspond to properties of single, leading hyphae. The model can be used to describe two-dimensional (2D) solid media fermentation experiments under varying culture conditions; the model can also be extended to consider growth in three-dimensional (3D), complex geometry substrates. (C) 1999 John Wiley & Sons, Inc.