Purification and characterization of a novel β‐agarase from Vibrio sp. AP‐2

Abstract

β‐Agarase was purified from the culture fluid of a porphyran‐decomposing marine bacterium (strain AP‐2) by ammonium sulfate precipitation, successive column chromatography and DNase and RNase treatment. The final enzyme preparation appeared to be homogeneous on polyacrylamide gel electrophoresis. The enzyme had a molecular mass of 20 kDa, a pH optimum of 5.5, and was stable in the pH region 4.0–9.0 and at temperatures below 45°C. The β‐agarase was a novel endo‐type enzyme which hydrolyzed neoagarotetraose, larger neoagarooligosaccharides and agar to give neoagarobiose [3,6‐anhydro‐α‐L‐galactopyranosyl‐(1→3)‐D‐galactose] as the predominant product. The enzyme did not act on K‐carrageenan. According to the criteria of Bergey's Manual of Systematic Bacteriology, the strain was assigned to the genus Vibrio. Copyright © 1990, Wiley Blackwell. All rights reserved