Density, porosity, and structure of dried cell walls isolated from Bacillus megaterium and Saccharomyces cerevisiae

Abstract

Helium displacement and nitrogen adsorption techniques were used to determine the density and porosity, respectively, of freeze-dried cell walls isolated from Bacillus megaterium KM and Saccharomyces cerevisiae. The densities were 1.302 and 1.180 g/cm3, respectively, suggesting noncrystalline solids. The porosities were extremely small, indicating that the cell walls had collapsed and become essentially impervious upon lyophilization.