西藏传统发酵酸奶源低温乳酸菌的筛选

Screening of Low-temperature Lactic Acid Bacteria from TibetanTraditional Fermented Yogurt

试验旨在筛选西藏传统发酵酸奶中性能优异的低温乳酸菌,寻找可作为发酵食品潜在发酵剂的优良乳酸菌菌种资源。以13株西藏传统发酵酸奶源乳酸菌为材料,采用低温(10℃)进行耐低温乳酸菌筛选,并通过不同温度生长情况、耐盐试验、耐酸试验、降亚硝酸试验、氨基酸脱羧酶试验和吲哚试验确定菌株的加工特性。结果显示,通过10℃低温条件培养筛选出的Lactobacillus paracasei CD3和CD5,其耐盐、耐酸、降亚硝酸盐特性较好,产酸能力较好,精氨酸、鸟氨酸、赖氨酸脱羧酶试验呈阴性,吲哚试验呈阴性,可作为发酵酸奶低温乳酸菌资源。

Aimedto select excellent low-temperature lactic acid bacteria(LAB)strains from Tibetan traditional fermented yogurt and to find excellent lactic acid bacteria resources which could be used as the potential starter of fermented food,13 lactic acid bacteria strains from Tibetan natural fermented milk were used as test materials.Low temperature strains were screened at 10℃,and according to growth conditions at different temperatures,salt tolerance test,acid tolerance test,nitrite reduction test,amino acid decarboxylase test and indole test,processing characteristics of these strains were determined.Lactobacillus paracasei CD3 and CD5 cultured at 10℃showed good qualities at salt tolerance,acid tolerance nitrite reduction and acid production capacity,and had negative results in arginine,ornithine and lysine decarboxylase tests and the indole test.Thus,Lactobacillus paracasei CD3 and CD5 could be used as excellent lactic acid bacteria strain resources of low-temperature fermentation.