海南黑山羊瘤胃液中乳酸菌的分离和鉴定

Isolation and identification of lactic acid bacteria from rumen fluid of Hainan black goat

以海南黑山羊瘤胃液为研究对象,对其进行乳酸菌的分离和鉴定,为黑山羊饲料的青贮提供优质的乳酸菌菌株。通过形态学观察及H_2O_2酶、糖发酵等生理生化试验对所分得菌株进行初步鉴定,并对分离得到的菌株进行16S r DNA基因扩增与测序。结果表明从黑山羊胃液中筛选出15株革兰氏阳性、H_2O_2酶阴性的乳酸菌疑似菌株,除菌株HBG20不能在pH 3.0条件下生长,其余菌株均能生长;三株代表菌株HBG11、HBG46和HBG86在低温5℃和高温55℃条件以及pH2.5时均能生长,同时在盐浓度为6.5%时也能生长。16S r DNA基因测序结果表明,菌株HBG11与耐久肠球菌(Enterococcus durans)同源性最高,菌株HBG46与植物乳杆菌(Lactobacillus plantarum)同源性最高,菌株HBG86与干酪乳杆菌(Lactobacillus casei)同源性最高。

Using rumen fluid of Hainan black goat as research object, the lactic acid bacteria was isolated and identified, in order to provide high quality lactic acid bacteria for the black goat feed silage. The isolated strains were preliminarily identified and characterized by morphological observation, catalase, sugar fermentation and other physiological and biochemical tests, and then the isolated strains were identified by 16S rDNA gene amplification and sequence analysis. There were 15 Gram-positive, catalase-negative strains isolated from the rumen fluid of Hainan black goat in the experiment. Except for strain HBG20, other strains can grow at pH 3.0 condition. Three representative strains HBG11, HBG46 and HBG86 can grow at low temperature 5 ℃, high temperature 55 ℃ and pH 2.5. Meanwhile, they can tolerate NaCl concentration of 6.5%. 16S rDNA gene sequence results showed that three strains HBG11, HBG46 and HBG86 showed the highest homogeneity with Enterococcus durans, Lactobacillus plantarum, Lactobacillus casei, respectively.