Chitinases from Vibrio: activity screening and purification of chiA from Vibrio carchariae

Fourteen species of Vibrio were screened for chitin-induced chitinase activ ity in culture medium. V. carchariae, V. alginolyrticus 283 and V. camphell ii showed high levels of activity. Screening on agar plates containing swol len chitin showed high levels of chitinase activity by the same three speci es, and also by V. fischeri and V. alginolyticus 284. An affinity purificat ion procedure was developed for the chitinase from ii. carchariae. The puri fied chitinase was active as a monomer with M-r 63 000-66 000, and displaye d activity toward polymeric chitin from acetylated chitosan or from crab sh ells. N-terminal sequence analysis and immunological cross-reactivity confi rmed that the enzyme belongs to the group A/chiA family of bacterial chitin ases,