IDENTIFICATION OF LACTOBACILLI AT GENUS LEVEL USING PCR

摘要

Lactic acid bacteria (LAB) are gram-positive, non-sporulating, microaerophillic bacteria whose main fermentation product from carbohydrate is lactate. The LAB especially the genera Lactococcus, Lactobacillus, Leuconostoc, Streptococcus, Bifidobacterium and Pediococcus, have been traditionally used as starter cultures for the fermentation of foods and beverages because of their contribution to flavor and aroma development and to spoilage retardation. In present investigation, 25 isolates alleged to belactobacilli were recovered from BCP-MRS agar plates streaked with milk samples which was collected from NDRI, Karnal campus. These isolates on the basis of Gram's staining and catalase test were subjected to PCR by using Lb1 and Lb2 23s rRNA lactobacilli specific PCR primers. All the isolates produced a PCR amplified product of 194 bp specific for lactobacilli species on agarose gel.