Cross flow filtration(CFF) has been successfully employed as a means of concentrating microbial cells and proteins. While the cross flow filtration of proteins has been investigated thoroughly and can be explained in terms of "gel layer" theory, the investigations on the microbial cells have been limited to the applications like concentration. In this study we aimed at studying the characteristics of CFF phenomena more systematically like in the case of proteins.
Unlike in proteins, CFF in microbial cells could not be explained by "gel layer" theory. Flux increase was independent of press drop(AP) which exceeds a certain level, but the flux increased with the flowrate in the hollow fiber. Gel layer theory employing the diffusivity based on "Stokes-Einstein" equation was applied to the system. But the prediction was far apart from the experimental data. Thus we suggested that the causes of the discrepancies between them might be due to the gel layer slippage or tubular pinch effect.