Abstract

COMPARATIVE ANALYSIS OF DIFFERENT STRAINS OF LACTOBACILLUS OF MILK USING MOLECULAR TECHNIQUE

Dr. Kiran B.*, Tanusri Paul and Dr. Lalitha V.

ABSTRACT

Four Lactobacillus species isolated from different samples of milk were collected and characterized by Gram staining, catalase test, mannitol motility test, indole test, methyl red ,Voges proskauer test and citrate utilization test. The DNA was isolated from all the strains and quantified from nanodrop (ND-1000) and subjected for agarose gel electrophoresis. Each DNA band in gel was characterized using gel Doc. The characterized DNA bands were subjected for Polymerase chain reaction to determine the sequence of DNA. The nucleotide sequence of all the strains were compared and the difference in banding pattern and functions of each set of gene were studied using random amplified polymorphic DNA technique (RAPD). RAPD analysis uses oligonucleotide primers that amplify certain sections of the genome by PCR to produce identifiable banding patterns, which are useful in differentiation. Two random primers (OPA11 and OPD20) were used to amplify the isolated colonies by RAPD-PCR method. The results were subjected for dendrogram analysis of similarity coefficient.

Keywords: Lactobacillus, DNA, PCR, RAPD, Characterization.