Hyperproduction and Application of α-Agarase to Enzymatic Enhancement of Antioxidant Activity of Porphyran

The nucleotide sequence of the gene for the α-agarase, AgaA33, from Thalassomonas sp. strain JAMB-A33 was determined. The open reading frame for AgaA33 was revealed to encode 1463 amino acid residues. We succeeded in extracellular production of recombinant α-agarase (AgaA33) efficiently using Bacillus subtilis as a host. This is the first report of recombinant production of α-agarase. Furthermore, we demonstrated that hydrolysis of α-1,3 linkages in porphyran, a sulfated polysaccharide from marine red algae, by α-agarase is an important step for improvement of its antioxidant activity with regard to free-radical-scavenging capacity and superoxide radical anion scavenging activity, whereas the hydrolysis of β-1,4 linkages in porphyran by β-agarase did not increase on the antioxidant activity markedly.

Keywords: α-Agarase; porphyran; antioxidant activity; recombinant enzyme