Nehru Arts and Science College, Coimbatore, Tamilnadu, India.
J Basic Microbiol. 2012 Dec;52(6):705-12. doi: 10.1002/jobm.201100315. Epub 2012 Feb 23.
The phenotypic and agar degrading features of an unidentified marine bacteria was investigated. The strain was Gram-negative, obligatory aerobic and non motile. On the basis of several morphological features and a phylogenetic analysis of the genes coding for the 16S rDNA, this strain was identified as Microbulbifer maritimus. On solid agar medium, this isolate produced extracellular agarase which causes agar liquefaction around the colonies. An extracellular agarase was purified by ammonium sulfate precipitation, gel filtration and ion-exchange chromatography on DEAE-cellulose. The purified protein migrated as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and it had a molecular mass of 75.2 kDa. The enzyme exhibited maximal activity at pH 7.5. The kinetic parameters of the enzyme were K(m) = 3 ± 0.19 mM, K(cat) = 160 ± 10 S(-1) and K(cat) /K(m) = 53 ± 10 S(-1) · mM(-1) .
研究了一株海洋细菌的表型和琼脂降解特性。该菌株革兰氏阴性，需氧，不运动。基于几个形态特征和对编码 16S rDNA 的基因的系统发育分析，该菌株被鉴定为海洋微杆菌。在固体琼脂培养基上，该分离株产生胞外琼脂酶，导致菌落周围的琼脂液化。胞外琼脂酶通过硫酸铵沉淀、凝胶过滤和 DEAE-纤维素离子交换层析进行纯化。纯化的蛋白质在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳中迁移为单一条带，分子量为 75.2 kDa。该酶在 pH 7.5 时表现出最大活性。酶的动力学参数为 K(m) = 3 ± 0.19 mM，K(cat) = 160 ± 10 S(-1)和 K(cat) / K(m) = 53 ± 10 S(-1) · mM(-1)。
