earticle

영어

Alginate is a major polysaccharide in brown algae and composed of two uronic acids, mannuronic acid and guluronic acid. Because of few information of uronic acid-metabolizing enzymes, utilization of the uronic acids as carbon source has been limited. As these backgrounds, we aimed at the development of enzymatic systems to produce alginate monomers and microorganisms able to utilize alginate monomers in this study. Two alginate lyases of Alg7D and Alg17C from a marine bacterium, Saccharophagus degradans 2-40, were overexpressed in Escherichia coli BL21(DE3) strain. SDS-PAGE analysis showed that Alg7D and Alg17C were expressed solubly in E. coli and their contents reached almost 80% of total protein. To hydrolyze alginate, crude protein solutions containing each enzyme were prepared and treated with sodium alginate sequentially. By thin layer chromatography, two-hours reaction with Alg7D at 50℃ resulted in hydrolysis of alginate with low DPs (about 2~4) and more addition of Alg17C gave full degradation of alginate polymer to its monomer (DP1). Alg17C was only able to hydrolyze sodium alginate to its monomer but its efficiency was lower than that of dual treatment of Alg7D and Alg17C.