Carrageenanolytic enzymes from marine bacteria associated with the red alga Tichocarpus crinitus

One hundred six bacterial strains (106 strains) were isolated from the Pacific red alga Tichocarpus crinitus, collected from the Troitsa Bay of Gulf of Peter the Great (Sea of Japan, Russia), and studied on their ability to degrade different samples of carrageenan as substrates. Some of the studied strains exhibited hydrolytic activity selectively to a total polysaccharide (kappa and lambda) from Chondrus armatus, other strains, to kappa/beta-carrageenan from T. crinitus, which did not possess the same effect to a total polysaccharide from T. crinitus. The strains with the highest enzyme activity (28 strains) were identified using 16S rRNA gene sequence techniques and classified to the phyla Bacteroidetes and Proteobacteria. Most (75%) of the studied carrageenase producers belong to phylum Bacteroidetes (21 strains). These strains were related with 7 phylotypes of the genera Aquimarina, Cellulophaga, Maribacter, and Zobellia (family Flavobacteriaceae of the class Flavobacteriia). Cellulophaga strains were the dominant group (35.7% of total) and closely related to species C. baltica and C. lytica with 99.8 and 99.9% sequence similarity, respectively. The remaining strains (7 strains) were represented by members of the genera Altererythrobacter (the family Erythrobacteraceae), Phaeobacter, Sulfitobacter, Tateyamaria (the family Rhodobacteraceae), and Sphingomonas (the family Sphingobacteriaceae) of the class Alphaproteobacteria and Psychrobacter (the family Moraxellaceae) and Vibrio (the family Vibrionaceae) of the class Gammaproteobacteria.