RANDOMLY AMPLIFIED POLYMORPHIC DNA (RAPD) FOR RAPID TYPING OF LACTOBACILLUS-PLANTARUM STRAINS

Randomly amplified polymorphic DNA (RAPD) has been used for rapid typi ng of Lactobacillus plantarum strains. RAPD was used with either purif ied chromosomal DNA serving as template in the polymerase chain reacti on, or with crude cell extracts, and using a 9-mer primer with 80% G C content. Amplified DNA was visualized by ethidium bromide staining after separation on agarose gels. Patterns from 20 Lact. plantarum str ains and two Lact. pentosus strains were analysed using the Pearson pr oducts moment correlation coefficient (r) and the unweighted pair grou p method with arithmetic averages (UPGMA). With some exceptions, the t wo sources of template DNA gave the same clusters and subclusters of s trains at the similarity level of 50%. About 50% of the strains could be individually separated from all the other tested strains. The buffe r brand, the amount of primer and crude cell extract used in the PCR-s tep were crucial for the final pattern.