Joseph A. Shaeiwitz

Yeast cell debris and protein partitioning in the poly(ethylene glycol)-poly(vinyl alcohol) biphasic system

Yeast cells, cell debris and protein partitioning have been investigated in the poly(ethylene glycol) (PEG) 8000/poly(vinyl alcohol) (PVA) 10,000 system. Cells and cell debris partition into the lower (PVA) phase over the pH range 4.8-7.5, and with up to 0.37 M KCl at pH 5.9. Protein partitioning is more pH-dependent in the PEG/PVA system than in the PEG/dextran system, and a significant fraction of the total protein is found at the interface at lower pH values. Significant, rapid purification of overproduced pyruvate kinase in a PEG/PVA system containing Blue Sepharose CL-6B particles is demonstrated.

Diffusion and mass transfer in micellar systems

Research on diffusion and mass transfer in micellar systems is reviewed. Models for interfacial transport at liquid/liquid interfaces, solubilization at solid/liquid and at liquid/liquid interfaces, and for detergency are discussed and similarities between these phenomena are elucidated. The literature on diffusion in micellar systems is discussed, especially in the region of the critical micelle concentration where previous investigators have presented results in disagreement with each other. Finally, the mechanism of micellar transport through membranes is also reviewed.