DNA fingerprinting of thermophilic lactic acid bacteria using repetitive sequence-based polymerase chain reaction

DNA fingerprints of lactic acid bacteria were generated by polymerase chain reaction using a primer based on the repetitive elements found in the geno me of Streptococcus pneumoniae (BOS-PCR). The method made it possible to id entify 37 isolates from ran milk, industrial starters and yogurt. Different iation at species, subspecies and strain level was possible for Lactobacill us delbrueckii subsp. lactis, Lb. delbrueckii subsp bulgaricus and Str. the rmophilus. BOS-PCR was also applied to studying the strain composition of a starter culture and the direct detect ion of strains in commercial ferment ed milk.