The dynamic flow behavior of viscous microbial broths will be correlated with transport phenomena in mechanically agitated, air-sparged fermenters. Special attention will be given to oxygen transport in broth containing organisms that grow in a mycelial morphology. It is hypothesized that mass transfer correlations based on assumptions of Newtonian behavior are inadequate for correlating mass transfer when the behavior becomes non-newtonian. A critical aspect of developing the engineering base for the emerging biotechnology industry is developing heuristics for scale-up from laboratory or pilot-scale equipment to production-scale equipment. The engineer's ability to make the scale-up accurately depends upon the use of accurate predictions of the behavior of the equipment. This project will determine if alternate correlations are needed as the flow behavior becomes more complex.