一株产溶菌酶海洋细菌S的鉴定及抑菌效果研究

Identification and inhibitory ability of a marine bacteria S producing lysozyme

从东海海泥中筛选到一株产新型溶菌酶的菌株S,这种溶菌酶(LY)能特异性地分解革兰阴性、阳性菌和真菌的细胞壁形成溶菌现象。菌株S为直杆状细菌,革兰染色可变,产芽孢、周生鞭毛,菌落边缘不平滑、不透明、不产生色素。菌体大小为(0.6～1.0)μm×(2.0～3.0)μm,V-P试验阴性,甲基红阴性,严格好氧,利用葡萄糖产酸,最适生长温度为30℃,耐6%NaCl。利用16SrRNA序列分析和生理生化试验进行鉴定,将其确定为芽孢杆菌属的一个新种,命名为蜡状芽孢杆菌,并构建了芽孢杆菌属相关种细菌在内的系统发育树;研究了LY对革兰阴性、阳性菌和真菌的抑菌效果。研究表明:LY的抑菌谱比鸡蛋清溶菌酶和其他微生物来源溶菌酶更为广泛。

A bacterial named S producing lysozyme was isolated from sea mud in the sea area of East China sea. The enzyme catalyzed the hydrolysis the mucopolysaccharides of the cell wall. The isolated strain S was identified by 16S rDNA sequence, morphological, biochemical and physiological identification. The cells of strain S were straight rods that were （0.6-1.0） IJm wide x（2.0~3.0） IJm long, gram-variable, peritrichous flagellated, gliding movement, forms endospores, V-P positive, methyl red negative. Colonies of strains aren＇t translucent and smooth with edges. The optimal temperature of the growth was 30 ~C, it be tolerant of 6% Nacl. Srtain S is aerobic, having a strictly respiratory of metabolism. Glucose is catabolized with the production of acid. A phylogenetic tree was constructed by comparing with the published 16S rDNA sequence of the relative bacteria species. In the phylogenetic trees, S and Bacillus cereus constitute a branch and Bacillus cereus was the closest relative with 96% sequence similarity. On the basis of physiology, morphology, structural characteristics and phylogenetic analysis, it is turned out that strain S belongs to Bacillus cereus. The antibacterial effects of lysozyme from Bacillus cereus on G, G- and fungi were studied. Results indicated that the lysozyme from Bacillus cereus had wider antibacterial spectrum than the lysozyme from eggwhite.