摘要
旨在得到一株具有褐藻胶降解能力的菌株。利用海藻酸钠作为唯一碳源,从腐烂马尾藻中筛选纯化得到一株降解褐藻胶能力较强的海洋细菌,编号X511。根据形态观察和理化指标,结合分子生物学技术鉴定该菌株为弧菌,命名Vibrio sp.X511。X511菌株的指数生长期5-16 h,适宜生长的盐浓度为2%-6%(W/V)。能在以葡萄糖、甘露醇、淀粉等为唯一碳源的培养基中生长。4%-6%(W/V)的盐浓度、海带粉、昆布多糖能延长该菌株的生长稳定期。该菌株在筛选培养基中发酵培养24 h胞内褐藻胶裂解酶粗酶活力达到12.68±0.13 U/m L;提取X511的褐藻胶裂解酶粗酶,分别对海藻酸钠、聚甘露糖醛酸和聚古罗糖醛酸三种多糖的酶解能力依次为:海藻酸钠>聚甘露糖醛酸>聚古罗糖醛酸。薄层层析(TLC)结果显示,该菌株胞内酶降解海藻酸钠的产物为三糖。结果表明,X511是一株盐耐受性较强、生长周期较短且能同时以海藻酸钠、聚甘露糖醛酸和聚古罗糖醛酸为碳源生长的海洋细菌。
The purpose of this work is to obtain a strain with an ability to degrade alginate. With sodium alginate as a sole carbon source,a strain of marine bacterium with the solid ability to degrade alginate was screened and purified from the cankered gulfweed,coded as X511.According to the morphological observation,physicochemical indexes and the techniques of molecular biology,the strain was identifiedas Vibrio,designated as Vibrio sp. X511. The exponential phase of strain X511 was about 5-16 h,and the suitable salinity for its growthwas around 2%-6%（W/V）. It was capable to grow in the culture medium with a sole carbon source like glucose,mannitol,or starch,etal. Also,4%-6%（W/V）of the salinity,the kelp powder,and the laminarin extended its stationary phase. The activity of intracellularcrude alginate lyase reached 12.68 ± 0.13 U/m L when the X511 fermented in the screening medium for 24 h. The intracellular crude alginatelyase was extracted,and its ability to digest alginate sodium,poly mannurono acid,and poly guluronic acid was measured as such order ：alginate sodium poly mannurono acid poly guluronic acid. The results of the Thin Layer Chromatography（TLC）showed that the enzymaticdegradation product of alginate sodium was trisaccharide. The above results indicate that the X511 is a marine strain with strong salt tolerance,short growth cycle,and it simultaneously utilizes the sodium alginate,poly mannurono acid,and poly-guluronic acid as its growing carbonresource.
作者
许超
熊亚茹
卢明倩
廖威
张云开
黄庶识
XU Chao XIONG Ya-ru LU Ming-qian LIAO Wei ZHANG Yun-kai HUANG Shu-shi(College of Life Science and Technology, Guangxi University, Nanning 530003 Biophysics Laboratory of Guangxi Academy, Nanning 530007 Guangxi Vocational and Technical College, Nanning 530226)
出处
《生物技术通报》
CAS
CSCD
北大核心
2017年第4期198-204,共7页
Biotechnology Bulletin
基金
国家自然科学基金项目(31560017)
广西自然科学基金重点项目(2014GXNSFDA118012)
关键词
褐藻胶
筛选
鉴定
盐耐受性
多糖利用
alginate
screening
identification
salt tolerance
polysaccharides use
