以西藏7个地区56份牧民家庭制作的发酵牛乳为原料采用稀释倾注法分析发酵微生物数量,通过菌种选择分离,采用传统分类与16S rRNA基因序列测定的方法分析传统发酵乳中乳酸菌的多样性.结果表明:56份发酵乳中乳酸菌数平均数量为(6.38±1.54) (lg(CFU/mL》),酵母菌平均数量为(5.27±1.63) (lg(CFU/mL》).共获得110株乳酸菌,其中,乳杆菌属Lactobaci llus)96株、明串珠菌属Leuconostoc)10株、乳球菌属(Lactococcus)2株、肠球菌属(Enterococcus)1株、片球菌属(Pediococcus)1株;96株乳酸杆菌中Lactobacillus casei 48株、Lactobacillus plantarum 18株、Lactobacillus parabuchneri9株、Lactobacillus fermentum 7株、L.delbrueckii subsp.bulgaricus5株、Lactobacillus breris4株、Lactobacillus acidophilus2株、Lactobacillus diolivorans3株,其中Lactobacillus casei占分离株的43.64％,是优势菌群.
Biodiversity and Quantitative Analysis of Lactic Acid Bacteria in Traditionally Fermented Milk Products from Seven Pasturing Areas of Tibet
To investigate the biodiversity of lactic acid bacteria from traditionally fermented milk products in Tibet,56 samples of milk products were collected from different herdsman families in seven pasturing areas of Tibet.Colony counting was conducted for lactic acid bacteria and yeasts separately by dilution and pour-plate method.Suspected strains of lactic acid bacteria were selected according to morphology and simple biochemical tests,and further identified by traditional taxonomy methods and 16S rRNA sequence analysis.Results showed that the average population of lactic acid bacteria in these fermented milk samples was (6.38 ± 1.54) (lg (CFU/mL)) compared to (5.27 ± 1.63) (lg (CFU/mL)) for yeast.A total of 110 lactic acid bacteria were found in all the tested samples,including 96 Lactobacillus strains,10 Lactococcus strains,2 Enterococcus strains and 1 Pediococcus strain.The 96 Lactobacillus strains were assigned to 8 species,including Lactobacillus casei (48),L.plantarum (18),L.parabuchneri (9),L.fermentum (7),L.delbrueckii subsp.bulgaricus (5),L.breris (4),L.acidophilus (2) and L.diolivorans (3).The 14 coccus strains were assigned to Lactococcus (2),Enterococcus (1) and Pediococcus (1).Lactobacillus casei was the predominant species,accounting for 43.64％ of the total isolates.This study may provide sufficient data to elucidate a huge biodiversity in lactic acid bacteria from Tibetan traditionally fermented milk products.
国家科技期刊平台
NSTL
万方数据
维普
