Kiran Kondepudi Kanthi, Chandra T S
Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600 036, India.
Appl Microbiol Biotechnol. 2008 Jan;77(5):1023-31. doi: 10.1007/s00253-007-1250-z. Epub 2007 Nov 13.
A moderately halophilic alkalitolerant Bacillus sp. Strain TSCVKK, with an ability to produce extracellular halophilic, alkalitolerant, surfactant, and detergent-stable alpha-amylase was isolated from soil samples obtained from a salt-manufacturing industry in Chennai. The culture conditions for higher amylase production were optimized with respect to NaCl, substrate, pH, and temperature. Maximum amylase production of 592 mU/ml was achieved in the medium at 48 h with 10% NaCl, 1% dextrin, 0.4% yeast extract, 0.2% tryptone, and 0.2% CaCl(2) at pH 8.0 at 30 degrees C. The enzyme activity in the culture supernatant was highest with 10% NaCl at pH 7.5 and 55 degrees C. The amylase that was partially purified by acetone precipitation was highly stable in various surfactants and detergents. Glucose, maltose, and maltooligosaccharides were the main end products of starch hydrolysis indicating that it is an alpha-amylase.
从钦奈一家制盐厂采集的土壤样本中分离出了一株中度嗜盐、耐碱的芽孢杆菌属菌株TSCVKK，该菌株能够产生胞外嗜盐、耐碱、具有表面活性且耐洗涤剂的α-淀粉酶。针对氯化钠、底物、pH值和温度对更高淀粉酶产量的培养条件进行了优化。在含有10%氯化钠、1%糊精、0.4%酵母提取物、0.2%胰蛋白胨和0.2%氯化钙的培养基中，于30℃、pH 8.0条件下培养48小时，淀粉酶的最大产量达到592 mU/ml。在pH 7.5、55℃和10%氯化钠条件下，培养上清液中的酶活性最高。通过丙酮沉淀法部分纯化的淀粉酶在各种表面活性剂和洗涤剂中高度稳定。葡萄糖、麦芽糖和麦芽低聚糖是淀粉水解的主要终产物，表明它是一种α-淀粉酶。
