Application of statistical experimental design for optimization of keratinases production by Bacillus pumilus A1 grown on chicken feather and some biochemical properties
Application of statistical experimental design for optimization of keratinases production by Bacillus pumilus A1 grown on chicken feather and some biochemical properties
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DOI：
10.1016/j.procbio.2009.12.007
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发表时间：
2010-05-01
影响因子：
4.4
通讯作者：
Nasri, Moncef
中科院分区：
文献类型：
--
作者：
Fakhfakh-Zouari, Nahed;Haddar, Anissa;Nasri, Moncef
从屠宰废水中分离到一株新的角蛋白水解酶产生菌，经鉴定为短小芽孢杆菌A1。采用Plackett-Burman设计法和中心复合设计法对短小芽孢杆菌A1产角蛋白酶的关键成分和产酶条件进行了优化，并用中心组合设计法对羽毛粉、大豆蛋白胨、氯化钠、氯化钾和磷酸二氢钾这五个重要变量的浓度进行了优化。优化后的培养基角蛋白酶产量(87.73U/ml)是初始培养基产量(25.9U/ml)的3.4倍。酶谱分析显示至少存在五种角蛋白水解酶。通过与非高压灭菌鸡毛孵育来检测胞外蛋白水解酶的活性。在45℃到60℃的温度下孵育6小时后，整个羽毛完全溶解。粗酶在60℃和以酪蛋白或角蛋白为底物的pH 8.5或55℃和pH 9.0时活性最高。(C)2009爱思唯尔有限公司。保留所有权利。
A new keratinolytic enzyme-producing bacterium was isolated from slaughter house polluted water and identified as Bacillus pumilus A1. Medium composition and culture conditions for the keratinases production by B. pumilus A1 were optimized using two statistical methods: Plackett-Burman design applied to find the key ingredients and conditions for the best yield of enzyme production and central composite design used to optimize the concentration of the five significant variables: feathers meal, soy peptone, NaCl, KCl, and KH2PO4. The medium optimization resulted in a 3.4-fold increase in keratinase production (87.73 U/ml) compared to that of the initial medium (25.9 U/ml). The zymography analysis shows the presence of at least five keratinolytic enzymes. The keratinolytic activity of the extracellular proteinases was examined by incubation with non-autoclaved chicken feathers. Complete solubilisation of whole feathers was observed after a 6-h incubation at temperatures ranging from 45 degrees C to 60 degrees C. The crude enzyme exhibited maximal activity at 60 degrees C and pH 8.5 or 55 degrees C and pH 9.0 using casein or keratin as substrates, respectively. (C) 2009 Elsevier Ltd. All rights reserved.