Diffusion Rates in Disrupted Bacterial Cells

The viscosity of the material resulting from squeezing Escherichia coli cells through an orifice in a French pressure cell has been shown to be very high and variable with temperature. Diffusion constants in this medium have been determined for sucrose, dextran, and beta galactosidase. The values found are: 1.07 × 10^-6cm²/second for sucrose, 0.36 × 10^-6cm²/second for dextran, and 0.025 × 10^-6cm²/second for beta galactosidase. The results agree with the idea that there is much interstitial space available for diffusion of small molecules in the cell medium in spite of the high viscosity, but that large molecules will be transported less readily.