A Comparison of Two Molecular Microbiological Methods, RAPD-PCR and DGGE-PCR for Identification of Lactobacilli Strains Isolated During Lighvan Cheese Making Process

The development of the dominant Lactobacilli population during traditional Liqvan cheese production was investigated using two different molecular methods of: culture dependent RAPD vs culture independent DGGE. Either one of the techniques showed a high degree of capability to identify and detect of this group of lactic acid bacteria. However, some differences were conspicuous during the detection of isolated Lactobacilli. In the culture dependent method RAPD, Lb. plantarum, Lb. paraplantarum and Lb. brevis were identified as the dominant strains in the final product while in the independent culture method DGGE, Lb. curvatus and Lb. sakei which could not be identified in the culture dependent method were also observed. Through RAPD it was possible to prepare the whole quantitative data for bacterial population while the other technique DGGE, reported just the semi-quantitative data. With regard to the advantages and disadvantages of each method, it can be concluded that none of the two are perfect but the limitations of one can be overcome by the versatility of the other. A combination use of the two methods can help obtain more trustable information about bacterial population dynamic during the cheese making process.