Vibrio sp.AP-2の産生するβ-アガラーゼの精製と特性

β-Agarases were purified from the culture fluid of a marine bacterium, Vibrio sp. AP-2, by am-monium sulfate precipitation, successive column chromatography, and nuclease treatment. The final enzyme preparations appeared to be homogeneous on polyacrylamide gel electrophoresis. The enzymes (agarases-a, -b, and-c) had molecular weight of 34, 000, 20, 000, and 18, 000 daltons, and the pH optimum of 6.5, 5.5, 7.0, respectively, and were stable in a pH region from 4.0 to 9.0, and at temperatures below 45°C. The agarases were β-agarase which degraded agar to yield neoagaro-oligosaccharides. Agarase-a and agarase-c hydrolyzed agar to give neoagarotetraose as the pre-dominant product, agarase-b gave neoagarobiose as the predominant product. The three enzymes did not react with κ-carrageenan.