Purification and characterization of extracellular inulinase from a marine yeast Pichia guilliermond

• 作 者: F.Gong;Z.Chi;J.Sheng;J.Li;
• 机 构: Unesco Chinese Center of Marine Biotechnology,Ocean University of China
• 出 处: 2008全国博士生学术论坛——海洋、水产领域
• 发表日期: 2007年期

　　The extracellular inulinase in the supernatant of cell culture of the marine yeast Pichia guilliermondii 1 was purified to homogeneity with a 7.2-fold increase in inulinase activity as compared to that in the supernatant by ultrafiltrafion,concentration,gel filtration chromatography(SephadexTM G-75)and anion-exchange chromatography(DEAE-Sepharose Fast Flow Anion-Exchange).The molecular mass of the purified enzyme was estimated to be 50.0 kDa.The optimal pH and temperature of the purified enzyme were 6.0 and 60 ℃,respectively.The enzyme was activated by Mn2+,Ca2+,K+,Li+,Na+,Fe3+,Fe2+,Cu2+,and Co2+.However,Mg2+,Hg2+ and Ag+ acted as inhibitors in decreasing activity of the purified inulinase.The enzyme was strongly inhibited by Phenylmethanesulphonyl fluoride(PMSF),iodoacetic acid,EDTA,and 1,10-phenanthroline.The Km and Vmax values of the purified enzyme for inulin were 21.1 mg ml-1 and 0.082 mg min-1,respectively.A large amount of monosaccharides were detected after the hydrolysis of inulin.