DNA fingerprints of lactic acid bacteria were generated by polymerase
chain reaction using a primer based on the repetitive elements found in the genome
of Streptococcus pneumoniae (BOX-PCR). The method made it possible to identify 37
isolates from raw milk, industrial starters and yogurt. Differentiation at species,
subspecies and strain level was possible for Lactobacillus delbrueckii subsp. lactis, Lb.
delbrueckii subsp bulgaricus and Str. thermophilus. BOX-PCR was also applied to
studying the strain composition of a starter culture and the direct detection of strains
in commercial fermented milk.