Rheological studies on Streptomyces fradiae ScF‐5 in submerged fermentation

Abstract

AbstractStudies on the rheology of Streptomyces fradiae ScF‐5 in a 10‐dm3 submerged fermenter for the production of intracellular glucose isomerase revealed that the apparent viscosity of the broth increased with increase in cell density up to 24 h and then declined while the density of the broth remained constant. The plot of shear stress versus shear rate at various fermentation periods showed the applicability of the Casson model. The yield stress and consistency index were found to increase gradually then decrease subsequently. In contrast, the flow behaviour index was less than unity and remained constant throughout the fermentation. The results contrast with the findings of other workers on the Newtonian and non‐Newtonian character of fermentation broths and the applicability of the power law model to such systems.