The effect of agitation on the morphology and penicillin production ofPenicillium chrysogenum

Abstract

Penicillium chrysogenum strain P1 was grown on complex media in 10 and 100 L agitated fermenters at various aeration rates and stirrer speeds. Samples were removed at intervals for measurements of the culture morphology. At high stirrer speeds (1000 and 1200 rpm) in 10-L fermentations the rate of decrease in the mean effective hyphal length was faster and the rate of penicillin production was lower than fermentations done at 800 rpm. At similar power inputs per unit volume in 100-L fermentations, the change in mean effective hyphal length was less and higher penicillin production rates were observed. This work comparing the results at two scales has shown that neither of the concepts of impeller tip speed or the dissipation rate of turbulence have general validity as a measure of hyphal damage. Our results are reasonaby well correlated by groups similar to circulation rate (ND(i) (3)/V) with lower circulation rates being beneficial. An adaptation of the van Suijdam and Metz relationship, expressed as P/D(i) (3)t(c), was most successful. Our data are insufficient to demonstrate the generality of the relationship but do support the concept of a dispersion zone around the impellers in which mycelia may be damaged. The greater the frequency of circulation of mycelia through the zone the greater the damage and the lower the rate of penicillin synthesis by the culture.

Effect of transport phenomena of Cladosporium cladosporioides on decolorization and chemical oxygen demand of distillery spent wash

“…It was decided in a report that the shape of the pellet and agglomeration mainly depend on the aeration and agitation in bioreactor (Smith et al 1990;Van Suijdam and Metz 1981). Pellet formation, roughness factor, and hyphal measurements were the predominant factors, affecting the decolorization and degradation of the distillery spent wash.…”

Submerged culture conditions for the production of mycelial biomass and antimicrobial metabolites by Polyporus tricholoma Mont.

“…The production of citric and itaconic acids by Aspergillus niger was increased when the fungus showed the morphology which is mentioned above (6). On the other hand, disperse growth is preferable for the production of penicillin by Penicillium chrysogenum (23), and cephalosporin by Cephalosporium acremonium (18).…”

Identification of Genes Associated with Morphology in Aspergillus niger by Using Suppression Subtractive Hybridization

“…For example, pelleted morphology is necessary for maximum production of citric acid by Aspergillus niger (9), itaconic acid by Aspergillus terreus (30), pravastatin precursor by Penicillium citrinum (17,47), and certain heterologous proteins by A. niger (57). It has been reported that filamentous growth is preferable for penicillin production by Penicillium chrysogenum (49) and fumaric acid production by Rhizopus arrhizus (6). The ability to obtain and maintain a particular morphology is one of the key parameters in the development of productive fungal fermentations.…”