开菲尔粒中优势菌的筛选及鉴定

[目的]筛选开菲尔粒中的优势菌系,为研究其共生机理以及开发新产品奠定基础。[方法]首先,将开菲尔颗粒粉碎,制备成不同稀释浓度的菌悬液,涂布于麦芽汁、PDA、MRS和改良的TJA培养基上。然后,在30℃和37℃条件下,分别在有氧和厌氧条件下培养7 d,挑选菌落,进行形态观察和生理生化试验。[结果]分离得到9株酵母菌和9株乳酸菌。其中克鲁维酵母属2株,假丝酵母属3株,酒香酵母属4株,肠膜明串珠菌葡聚糖亚种1株,乳酸乳球菌乳脂亚种2株,高加索酸奶乳杆菌3株,瑞士乳杆菌1株,德氏乳杆菌保加利亚亚种1株,德氏乳杆菌乳亚种1株。[结论]开菲尔粒中共有18株优势菌,包括9株酵母菌,3株乳酸球菌和6株乳酸杆菌。

Isolation and Identification of Preponderant Flora from Kefir Grians

[Objective] To isolate the preponderant flora from kefir grains,and built the groundwork of researching on the symbiosis mechanism of them and exploitation of new taste kefir.[Method] Kefir grains were firstly crushed to pieces and prepared suspensions of these pieces in different concentration,and spread on the malt extract medium,PDA medium,MRS medium or tomato juice medium.They were cultured in the conditions of aerobic and anaerobic at 30 ℃ and 37 ℃ for seven days,and screened the single colonies and observed their shape,and the results of experiments of physiology and biochemistry.[Result] 9 yeasts and 9 lactic acid bacteria were screened from kefir grains,yeast were identified as Kluyveromyces(2),Candida(3),Brettanomyces(4);lactic acid bacteria were identified as Leuconostoc mesenteroides subspecies Dextranicum(1),Lactococcus lactis subspecies Cremoris(2),Lactobacillus kefir(3),Lactobacillus helveticus(1),Lactobacillus delbeueckii subspecies bulgaricus(1),and Lactobacillus delbrueckii subsp.lactis(1).[Result] Total 18 strains were screened from kefir grains,9 of them were yeast,3 of them were lactococcus,and 6 of them were lacbobacillus.