STUDIES ON ALGAL CUTICLE

A chemically resistant cuticle fraction was isolated from 5 phaeophycean, 1 rhodophycean, and 11 chlorophycean marine algae using acid treatment alone, or acid treatment followed by leaching in cupra‐ammonium. In Cladophora rupestris and Chaetomorpha melagonium this fraction consists of several alternate microfibrillar and amorphous layers similar in appearance to those seen in innermost carbohydrate‐rich regions and amount to about 1/10 or more of the cell wall thickness. In Porphyra umbilicalis and Padina vickersiae it is a single layer less than I μ thick, accounting for 1/50–1/100 of the cell wall in Porphyra, and 1/5–1/10 of the cell wall in Padina. The cuticle fractions of all 4 algae contain surprisingly large amounts of protein (about 70% in Cladophora and 80% in Porphyra). Similarities in the behavior of cuticles obtained from the other 12 species studied suggest that they may have a similar protein‐rich composition. Copyright © 1969, Wiley Blackwell. All rights reserved