Abstract: G-PAGE was used to investigate the protease patterns and activities in 11 species of Laminaria Lamx., Undaria Suringar and Porphyra C. Ag. It was shown that (1) the patterns and activities of the protease were pH dependent and the optimum pH for protease activities was 8.0; (2) the more closer the inter-species relationship, the more similarities were observed among the patterns and activities of the proteases; (3) two protease patterns (19 kD, 18 kD) in the eight species of Laminaria were regarded as the genetic indicator of Laminaria; (4) the results suggested that the G-PAGE analysis of proteases could be valuable in the systematic taxonomic study of algae.

Key words: Laminaria, Undaria, Porphyra, Protease, pH, G-PAGE, Taxonomy