【摘要】 研究1株曲霉JXSD-01发酵液中内切壳聚糖酶(eCSN)的纯化与功能,以寻求一种清洁的生产不含单糖的壳寡糖的方法。经分析,不含外切酶活性的eCSN蛋白酶比活力>50U/mg,分子质量为25kD,酶的最适温度为63℃,最适pH6.5。经N末端测序,内切壳聚糖酶的N端序列为YNLPNNLKQ。eCSN用于天然大分子壳聚糖的生物降解,可获得分子质量在1000～3500D的寡糖聚合物,其中无单糖污染,达到国际食品级壳寡糖质量标准。更多还原

【Abstract】 In order to obtain a novel and clean preparation process for food-grade oligo-chitosan without monosaccharide,an endo-chitosanase(eCSN) that can degrade chitosan was purified from fermentation broth of Aspergillus JXSD-01 and its properties were also explored.The specific activity of the eCSN was above 50 U/mg,and its molecular mass was approximately 25 kD.The optimal reaction temperature and pH of the enzyme were 63 ℃ and 6.5,respectively.The sequence of N-terminal in the enzyme was YNLPNNLKQ.The eCSN could used for the degradation of chitosan as a natural large molecule to produce oligosaccharides with molecular weights in the range of 1000-3500 D.The obtained oligosaccharides did not contain monosaccharides and could reach the international quality standard for food-grade oligo-chitosan.更多还原