西宁传统发酵酸奶中乳酸菌的分离鉴定及发酵特性研究

Identification and fermentability of lactic acid bacteria from traditional fermentation yogurt in Xining

采用纯培养方法从采集于西宁市区的4份传统发酵酸奶样品中分离得到5株乳酸菌,通过16S r DNA基因序列,并结合形态特征,确定这些乳酸菌的分类。通过测定产酸能力,产胞外多糖能力,降解亚硝酸钠能力和降解乳糖能力,比较了它们的发酵特性。筛选出了两株具有优良发酵性能的乳酸菌,即植物乳杆菌A和植物乳杆菌D,为乳制品和果蔬制品的发酵应用奠定了菌种基础。

Five lactic acid bacteria were isolated from 4 traditional fermentation yogurt samples in the pasturing area of Xining by culture-dependent methods.These isolates were identified by 16 S r DNA and physiological characteristics.Their fermentation characteristics were compared by the abilities of acid production,exopolysaccharide production,nitrite degrade and lactose degrade.As a result,one lactic acid bacteria designated as Lactobacillus plantarum A and Lactobacillus plantarum D were obtained and laid a foundation for dairy products and vegetable fermentation application.