A simple method for isolation of lipopolysaccharides from Pseudomonas aeruginosa and some other bacterial strains.

Abstract

A simple procedure for the isolation of bacterial lipopolysaccharides was developed. The method consists of the following three steps; recovery of lipopolysaccharides in an insoluble form together with denatured proteins in a hot MgCl2-Triton X-100 solution (step 1), solubilization with EDTA-Triton X-100 (step 2) and precipitation with MgCl2 (step 3). A good yield of lipopolysaccharides was obtained with most of the Pseudomonas strains tested. Although the yield was lower with strains belonging to Salmonella and Escherichia, irrespective of whether they are smooth-type or rough-type strains, the amounts obtained from 100mg of cells as dry weight were sufficient for detailed chemical characterization. The gel-electrophoretic profiles of the lipopolysaccharides prepared by the present method were essentially the same as those of the lipopolysaccharides prepared by the conventional phenol-water method. The method allowed us to prepare lipopolysaccharides from a large number of bacterial strains in one day.