Author(s): Karnewar SD, Dhawale RN, Dudhare MS and Batish VK

Abstract: Lactic acid bacteria (LAB) are gram positive non sporulating, Microaerophillic bacteria whose main fermentation product from Carbohydrate is lactates. The LAB especially the genera Sactococcus, Lactobacillus, Leuconostoc, Streptococcus, Bifidobacteria and Pediococcus, Have been traditionally used as starter cultures for the fermentation of foods and beverages because of their contribution through flavor and aroma development and to spoilage retardation. Lactobacilli are found in milk, although their numbers are few and in certain cases even their absence has also been reported (Hill and Thornton, 1958) [3]. It is very difficult to isolate lactobacilli from milk as they are outnumbered by other microorganisms. Thus rendering most of the normal nutrient media unsuitable for their isolation. With the advent of molecular biology techniques, it is now possible to classify bacteria by comparing their genomes. Genotyping has many advantages over traditional typing procedures The rRNA locus is a genetic unit of broad evolutionary interest (Cedergen et al. 1988). In prokaryotes two additional assumptions are basic for the validity of this approach, namely that lateral gene transfer has not occurred between rRNA genes and that the amount of evolution or dissimilarity between rRNA sequences of a given pair of organisms is representative of the variation by the corresponding genomes (Rochelle, 1992) [7].In present investigation 25 isolates alleged to be lactobacilli were recovered from BCP-MRS agar plates streaked with milk samples which was collected from NDRI, Karnal campus. These isolates on the basis of Grams staining and catalase test were subjected to PCR by using Lb1 and Lb2 23s rRNA lactobacilli specific PCR primers. Tll the isolates produce a PCR amplified product of 194 bp specific for lactobacilli species on agarose gel which are consistent with the earlier observations of Suja (2003) [9].

Pages: 72-73 | Views: 811 | Downloads: 307

Download Full Article: Click Here