A mathematical model for the growth of mycelial fungi in submerged culture.

A new kinetic model is developed which provides a simple quantitative description of the growth of mycelial organisms. The main concept of this model is that the fungal hypha can be regarded as a form of self-extending tubular reactor. Nutrients are absorbed along the length of the "reactor," converted into cell envelope precursors and transported forward to the growth tip where they become consumed in the process of extension; Michaelis-Menten kinetics are assumed to operate at this point. The model is capable of predicting changes in the rates of hyphal extension, branching, and fragmentation during mycelial growth in submerged culture and consequently variations in the hyphal growth unit. Simulation studies using the model are presented and the results are evaluated with reference to data from an industrial-type fed-batch penicillin fermentation.