MORPHOLOGICAL MEASUREMENTS ON PENICILLIUM-CHRYSOGENUM BROTHS BY RHEOLOGY AND FILTRATION METHODS

The morphology parameters of mycelial culture (Penicillium chrysogenum ) were measured and quantified by rheology and filtration methods. Two of the morphology parameters obtained from rheology measurements, del ta defined by the Casson equation and delta defined by intrinsic visco sity, were found to vary systematically with broth age and with the ob served morphology by microscopy. Three of the filtration parameters, h yphal density, Kozeny constant, and index of compressibility, are demo nstrated as sensitive indicators of the broth age and mycelial morphol ogy. Two of the morphology parameters, delta and delta, were used to c ross-correlate with hyphal density. Because various mycelial fermentat ions require different growth morphologies (pellet and filament) for o ptimum product yield and the morphology of mycelial broths varies with broth age, it is suggested that these morphology parameters could be used to represent the morphology of mycelial broths quantitatively. (C ) 1993 John Wiley & Sons, Inc.