Morphology of Trichoderma reesei QM 9414 in submerged cultures

Abstract

The microscopic morphology of Trichoderma reesei QM 9414, growing in submerged culture, was studied by image analysis. The morphology was characterized by the total hyphal length, the total number of tips, the number of actively growing tips, and the length of the main hypha. To describe the growth of a single mycelium a simple model is set-up. The main features of the model are: (1) saturation type kinetics for the tip extension of the individual branches within the mycelium; and (2) random branching with a frequency function, which is proportional to the total hyphal length. The model is used to simulate a population of mycelia, where spore germination is described with a log-normal distribution. From the simulation of the population, the average properties of the mycelia, e.g., the average total hyphal length, are calculated, and by fitting the model to experimental data the model parameters are estimated. Finally, the distribution function with respect to the mycelia properties, that is, number of tips and total hyphal length, is calculated, and it corresponds well with the experimental determination of the distribution function. (c) 1995 John Wiley & Sons Inc.

Simulation of growth of a filamentous fungus in 3 dimensions

“…The present model is based on a model for early growth and branching following germination of Trichoderma reesei QM 9414 (Lejeune et al, 1995). In the original model the parameters were fitted to average properties of the mycelia (total hyphal length, total number of tips), and it correctly predicted the corresponding frequency distributions of these properties.…”

Metabolic Engineering of the Morphology of Aspergillus oryzae by Altering Chitin Synthesis

“…In microscopic morphology, single hyphal elements or hyphal populations are characterized by measuring their dimensions, such as total hyphal length, number of tips, hyphal diameter, number of nuclei per cell (20), and number of membranous organelles per cell (1). Recently, there has also been considerable effort to deduce the kinetics of submerged growth and branching (8,16,28,29), adding important details to the understanding of hyphal growth.The relationship between the mycelial morphology and the rheological properties of the cultivation medium has been the subject of a number of studies (2,15,19,25). The hyphal length per branch (length of the hyphal growth unit [l HGU ]) affects the overall morphology (34); a low l HGU has been associated with the formation of clumps smaller than those formed at a high l HGU (2).…”

“…In microscopic morphology, single hyphal elements or hyphal populations are characterized by measuring their dimensions, such as total hyphal length, number of tips, hyphal diameter, number of nuclei per cell (20), and number of membranous organelles per cell (1). Recently, there has also been considerable effort to deduce the kinetics of submerged growth and branching (8,16,28,29), adding important details to the understanding of hyphal growth.…”

Ecological Complexity and the Success of Fungal Biological Control Agents

“…Knudsen & Stack [89] introduced the idea of a simulation model for hyphal growth of a fungal hyperparasite through soil and use of the model to predict the incidence of hyperparasitism of sclerotia of certain soilborne plant pathogens. Lejeune and Baron [90] and Lejeune et al [91] simulated the 3D growth of the filamentous fungus Trichoderma reesei, based on properties of mycelial growth (total hyphal length and total number of tips). Cross and Kenerley [92], using a combination of the Ratkowsky and Arrhenius equations, modeled colony growth of T. virens at different temperatures.…”