Alginate Lyases of Pseudomonads*

Two kinds of pseudomonads, Nos. 8 and 9 were isolated from sea sand and decaying algal fronds. Crude extracts from these bacterial cells grown on an alginate medium and the partially purified enzyme preparations obtained therefrom degraded eliminatively various substrates such as commercial alginate, mannuronic acid-rich (M-rich)and guluronic acid-rich (G-rich) alginates, a short-chain polyguluronide with $DP¯$ 15 (SG) and its reduced derivative and a short-chain polymannuronide with $DP¯$ 11 (SM) in different manners. However, a highly purified lyase preparation from Pseudomonas No. 9 showed the activity for SG but not for SM, and the independent existence of a “polyguluronide lyase” was ascertained.