Cell Wall Composition of the Generic Phase of Bangia atropurpurea (Rhodophyta)

Mechanically isolated cell walls were prepared from the generic phase of Bangia atropurpurea and chemically characterized. Electron microscopic examination of cell wall preparations revealed them to be morphologically similar to walls of whole thalli and free from protoplasmic contamination. The chemical composition of over 92% of the total wall weight was determined and polysaccharides were the major wall components (72% of wall weight). Mannan (at least part of which is β-1, 4-linked) and a water soluble galactan fraction consisting of both D- and L-galactose residues in a ratio of 1:1.1 represents a large proportion of the carbohydrate content of isolated cell walls. In addition, 3,6-an-hydrogalactose is probably associated with the water-soluble galactoses. The presence of cellulose could not be demonstrated. Protein was a significant wall component (10.6% of total wall weight) and consisted of at least 16 amino-acids, including hydroxyproline (0.3% of wall weight). Walls also contained 8.4% lipid and 1.4% ash.