本试验从健康未断奶的仔猪粪便中分离出一株对猪链球菌有较好抑制作用的菌株1-6,排除有机酸、过氧化氢、菌体细胞等的干扰后仍有抑菌活性;用蛋白酶K处理后,其抑菌活性消失;进一步硫酸铵沉淀、透析处理后,其抑菌活性显著增强,因此确定该抑菌活性物质为蛋白类物质,进而确定菌株1-6为细菌素产生菌。通过个体及菌落形态、生理生化试验、16S rRNA基因序列同源性比较,结果证明1-6菌株为屎肠球菌。
A strain,1-6,displaying antimicrobial activity against Streptococcus suis,was isolated from healthy and un-weaned piglet's fresh feces.The antimicrobial role remained active after eliminating some interference factors(organic acid,oxid catalase,bacteria cells and so on)and was inactived when treated with Proteinase K.By ammonium sulphate precipitation,dialysis,the antimicrobial activity was enhanced.The result showed this inhibitory material had the features of protein,and could be classified as bacteriocin.Based on the morphological,physiological and biochemical characteristics as well as 16S rRNA gene sequence analysis,strain 1-6 was identified as Enterococcus faecium.