Microbial production of levanase for specific hydrolysis of levan

详细信息    查看全文

• 作者：Imen Dahech ; Hanen Ben Ayed ; Karima Srih Belghith ; Hafedh Belghith ; Hafedh Mejdoub
• 关键词：Levanase ; Purification ; Fructooligosaccharides
• 刊名：International Journal of Biological Macromolecules
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：60
• 期：Complete
• 页码：128-133
• 全文大小：831 K

文摘

A newly isolated bacterial strain from Tunisian thermal source was selected for its ability to produce extracellular levanase when grown on levan substrate. The optimization of carbon source, nitrogen source, temperature and initial pH of the growth medium in submerged liquid cultures were investigated. In fact, levan was found to be a good inducer of levanase enzymes. The optimal temperature and pH of the levanase activity were 40 ?C and 6.4, respectively. This enzyme exhibited a remarkable stability and retained 75 % of its original activity at 55 ?C for more than 1 h at pH 6.4. Crude enzyme of the strain rich in levanase was established for the hydrolysis of levan in order to produce fructooligosaccharides with variable degrees of polymerization which could be used in important fields such medicine, food-processing industry and cosmetic. The extracellular levanase of the strain was then, partially purified as determined by SDS-PAGE. The purification was achieved by ammonium sulfate precipitation, gel filtration and DEAE cellulose chromatographies.