Studies on the rheology and oxygen mass transfer in the clavulanic acid production by Streptomyces clavuligerus

In the present work rheological characteristics and volumetric oxygen trans fer coefficient (k(L)a) were investigated during batch cultivations of Stre ptomyces clavuligerus NRRL 3585 for production of clavulanic acid. The expe rimental rheological data could be adequately described in terms of the pow er law model and logistic equation. Significant changes in the rheological parameters consistency index (K) and flow behavior index (n) were observed with the fermentation evolution. Interesting correlations between the consi stency index (K)/biomass concentration (C-X) and the flow behavior index (n )/biomass concentration were proposed. Volumetric oxygen mass transfer coef ficient (k(L)a) was determined by the gas balance method. Classical correla tion relating the volumetric oxygen mass transfer coefficient to the operat ing conditions, physical and to transport properties, including apparent vi scosity (.(ap)), could be applied to the experimental results.