The cell-wall constituents of Apjohnia laetevirens Harvey

Abstract

Cells of the green alga, Apjohnia laeterivens Harvey, have been ruptured in a Waring blendor in order to remove the majority of the protoplast from the cell-wall substances.

The cell walls have been shown to contain, apart from extraneous protoplasmic constituents and some encrusting bryozoa, framework microfibrils of cellulose 1 which seem to be associated with pectin-like materials, arabinogalactan matrix substances and, perhaps, a polysaccharide-protein complex; these components appear to represent about 90% of the organic substances in the original organic-solvent extracted cell walls.

Less than 25 % of the initial cellulose 1 was converted to cellulose 11 during treatments of several hours' duration at room temperature with aqueous solutions of 24% KOH and 17.5 % NaOH. The low degree of conversion is attributed to the presence of highly ordered and/or large "crystalline" aggregates of ß-1,4'-glucan molecules in the cellulosic micelles of the framework microfibrils of the cell walls.