Molecular Characterization of Lactobacillus Acidophilus by SDS-PAGE and Plasmid Analysis

Lactobacillus acidophilus is well known because of its probiotic role hence gain importance in food and nutrition. Keeping in view the importance of Lactobacillus acidophilus there was dire need to identify the strain accurately. Phenotypically identified 27 strains were characterized by SDS-PAGE and plasmid profile. SDS-PAGE analysis had shown that most of the strains were strongly coupled with little variation. Only two strains do not belong to any cluster showing the authenticity of SDS-PAGE. Further Plasmid profile of DNA of lactobacillus acidophilus represent the characteristics pattern, and among 27 strains 15 isolates showed the presence of plasmid. Based on number and size of plasmid the strains are grouped into three distinct groups. A combination of SDS-PAGE and plasmid analysis has been shown a practical method to use for identification of Lactobacillus at species level. However the conventional method should be combined with genotypic method for a thorough analysis of strain