Characterization Of Agarase From Alteromonas Sp.nov.SY37-12 And Analysis On Degradation Product

In order to gain the ocean oligosaccharides with the bioactivities, we have studied the bacterial biochemical properties, the different effects on producing agarase, agarase characterization and degradation products beginning with the isolation of the bacterium.1 A bacterium strain SY 37-12 with the high level of agarase was isolated from seaweed and the isolate was named as Alteromonasp. nov. SY 37-12 according to the Bergey's manual of determinative bacteriology (9th ed.). Physical and chemical mutation can increase the bacterial ability in producing the agarase.2 An optimum culture medium was determinate as: 0.3% agar, 0.1% K2HPO4, 0.1% NH4C1, 2%NaCl, 0.05%MgSO4, 0.01%CaCl2. An optimum culture conditions were determinate as: 125ml liquid culture media in 250ml Erlenmeyer flask, pH7.0, culture temperature 35, rotation rate ISOrpm and culture time 20h.3 We study the basic properties of agarase produced by Alteromonas sp. nov. SY 37-12. Agarase was extracted by 80% saturation with solid sulfate ammonium. The enzyme was purified 27.6 fold and the molecular weight of the agarase is 39.5KDa by SDS-PAGE. The basic properties of the enzyme were studied as follows: The optimum pH, the optimum temperature and the optimum NaCl concentration are pH7.0, 35 and 1% respectively. The enzyme is activated by K. Ca2+. Na+. Mg2+and inhabited by Fe3+. Zn2+ Sn2+ Hg2+ Ba2+. The enzyme is stable at temperatures up to 35癈.4 The composition and structure of main degradation product were examined by MALDI-TOF-MS and 13C-NMR. The agarase belongs to |3-agarase and can hydrolyze the (3-1,4-glycosydic linkages of agar, yieldingneoagarotetraose and neoagarohexaose as the main products.5 The antioxidative activities and antibacterial activities of neoagarooligosaccharide were studied. The neoagarooligosaccharide have the high antioxidative activities in scavenging the lipid peroxidation, removing theOH and H2O2. The neoagarooligosaccharide, H7 shows the antibacterial activity. The MIC of H7 against E.aerogenes and P.aeruginosa are 2.5mg/mL and I Omg/mL respectively.