Novel enzymes produced by actinobacteria growing on seaweed

Abstract

Actinobacteria were screened for their ability to produce seaweed polysaccharide-degrading enzymes. Streptomyces strains FA24 and FA56 grown on seaweed which could both produce alginate lyase. The polysaccharide-degrading enzymes were precipitated with ammonium sulphate and then purified using dialysis and anion exchange chromatography. Polysaccharide-degrading enzymes from Streptomyces sp. FA24 had a molecular mass range of 15 – 37 kDa while enzymes from Streptomyces sp. FA56 had an apparent molecular mass of 23 kDa. The optimum pH for activity of polysaccharidedegrading enzymes from Streptomyces spp. FA24 and FA56 against sodium alginate were 8.0 and 7.5, respectively. These enzymes of both strains also showed maximum activity at 30o C. Streptomyces spp. FA24 and FA56 were observed as having a 95% and 99% 16S rRNA gene sequence similarity, respectively, to previously recorded sequences of type strains of actinobacteria isolates, indicating that Streptomyces sp. FA24 could be novel species. The enzymes purified from Streptomyces spp. FA24 and FA56 grown on Bull Kelp powder may be novel alginate lyases.

Keywords

• actinobacteria
• polysaccharide-degrading enzymes
• seaweed