A morphologically structured model for mycelial growth and secondary metabolite formation

A morphologically structured model is proposed to describe the batch fermen tation of lovastatin according to the growth kinetics of filamentous microo rganisms. Three kinds of hyphae are considered in the model: actively growi ng hyphae, non-growing hyphae and deactivated hyphae. Furthermore, actively growing hyphae consist of three morphological compartments: apical compart ment which gives rise to hyphal tip extension; subapical compartment which is related to hyphal branching; and hyphal compartment, which is only respo nsible for secondary metabolite formation. The kinetics of mycelial growth mechanism is summarized and applied in modeling lovastatin fermentation. A Michaelis-Menten kinetic model with substrate inhibition is proposed for pr oduct formation. As expected, the model simulations fit well with experimen tal data, obtained either from a laboratory scale 10L fermenter or from a p ilot-plant scale fermenter.