MORPHOLOGY OF TRICHODERMA-REESEI QM-9414 IN SUBMERGED CULTURES

The microscopic morphology of Trichoderma reesei QM 9414, growing in s ubmerged culture, was studied by image analysis. The morphology was ch aracterized 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 t he total hyphal length. The model is used to simulate a population of mycelia, where spore germination is described with a log-normal distri bution. 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 ar e estimated. Finally, the distribution function with respect to the my celia properties, that is, number of tips and total hyphal length, is calculated, and it corresponds well with the experimental determinatio n of the distribution function. (C) 1995 John Wiley and Sons, Inc.