BACTERIAL ALGINATE LYASE - ENZYMOLOGY, GENETICS AND APPLICATION

Alginate is a heteropolysaccharide comprised of mannuronate and guluronate. Three different types of alginate-degrading enzymes, alginate lyases A1-I, A1-II and A1-III, were produced by a bacterium isolated from a ditch. A1-I (63 kDa) was active on both brown seaweed (non-acetylated) and bacterial (acetylated) alginates, whereas A1-II (23 kDa) and A1-III (40 kDa) were specific to brown seaweed and bacterial alginates, respectively. The gene for A1-I was cloned, analyzed and a possible molecular route for the generation of A1-II and A1-III through post-translational processing of A1-I was established. Novel physiological and food technological functions of alginate were derived by depolymerization of the polymer molecule. A pyrogen-free A1-III was massively produced by genetically engineered Gram-positive microbe.s and is considered as a possible therapeutic agent for the treatment of patients with cystic fibrosis.