一株海洋细菌所产琼胶酶酶学特性的研究  

Characterization of Extracellular Agarase from an Agarolytic Bacterium

作　　者：蔡俊鹏[1] 许少丹[1] 

机构地区：[1]华南理工大学轻工与食品学院,广东广州510640

出　　处：《现代食品科技》2008年第12期1217-1221,共5页Modern Food Science and Technology

摘　　要：从海水中分离筛选到一株高活力的海洋琼胶降解菌2.2-g。通过硫酸铵盐析、透析袋透析、离子交换柱层析和凝胶柱层析,得到了电泳纯的琼胶酶样品,通过SDS-PAGE电泳,其分子量约为55kDa。该琼胶酶的最适pH值和温度分别为7.0和55℃。Mg2+和Ca2+对酶促反应有较强的促进作用,而Mn2+、Zn2+、NH4+、EDTA和SDS等则有不同程度的抑制作用。酶解产物的质谱和核磁共振谱结果证明,该琼胶酶降解琼胶后得到由新琼二糖、新琼四糖、新琼六糖组成的混合物,证明该琼胶酶为β-琼胶酶。An agar-decomposing strain 2.2-g was isolated and selected from sea water. The enzyme was achieved by amrnonium, dialysis and DEAE-cellulose separation, and its molecular mass was determined as 55 kDa. The most suitable pH and temperature of the enzyme were 7.0 and 55℃, respectively. Mg〉 and Ca2＋ can be used as enzyme activators for this extracelhilar agarase, while Mn2＋, Zn2＋, NH4＋, EDTA and SDS partially or completely inhibited its activity. MS and NMR analysis showed that the enzyme is a β-agarase, which was further validated by the components of its degraded products （ neoagarobiose, neoagarotetose and neoagarohexaose）.

关 键 词：海洋细菌 Β-琼胶酶 酶学性质 酶解产物 

分 类 号：Q93[生物学—微生物学]