以从海南三亚近海海水中采集的样品为研究对象, 利用平板筛选法筛到一株产酯酶的中度嗜盐菌菌株LYG1-1。通过形态学、生理生化及16S rRNA 序列分析, 发现该菌株为革兰氏阴性菌, 其最适生长温度为30℃, 最适生长pH 为7.5, 最适NaCl浓度为10%。16S rRNA基因序列分析显示, 菌株LYG1-1与Halomonas salina 亲缘性最近, 16S rRNA基因序列相似性为99.72%。在含10% NaCl的0.05mol·L^-1 Tris-HCl(pH 8.0)缓冲液中, 45℃条件下作用, 酶活性最高, 40℃处理24h仍保持83%的活性。金属离子浓度为5mmol·L^-1时, Ca²⁺、Mg²⁺对菌株LYG1-1酶活具有明显的激活作用, Hg²⁺表现出强烈的抑制作用。

Using plate screening method, a moderately halophilic strain LYG1-1 was isolated from seawater sample offshore of Sanya. According to physiological and biochemical characterizations, 16S rRNA sequences and phylogenetic analysis, cells were Gram-negative. It grew best at 30℃, pH 7.5 and with the presence of 10% NaCl. Phylogenetic analysis based on 16S rRNA gene sequence showed that it belonged to the genus Halomonas, having the highest similarity (99.72%) with Halomonas salina. The maximum esterase activity was observed at 45℃, pH 8.0. The effects of various divalent cations were studied based on the activity of esterase from Halomonas sp. The concentrations of 5 mmol·L^-1 Mg²⁺ and Ca²⁺ enhanced the esterase activity of LYG1-1, while the presence of Hg²⁺ strongly inhibited its activity.