RAPD-PCR Characterization of Brewery Yeast and Beer Spoilage Bacteria

Abstract

Commercially available oligonucleotide primers (10-mers) were used in a random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) to screen and characterize potential beer-contaminating bacteria. The species identification of Lactobacilli, Pediococci, Leuconostoc, and others was achieved using four different primers in the RAPD-PCR. For each bacterial species, each primer produced a unique and characteristic “core” fingerprint pattern. Using the core patterns as a guide, we were able to distinguish and recognize unknown contaminants obtained during regular testing by our quality control laboratories. The procedure is faster than traditional characterization techniques—the identification of a single colony was typically achieved in less than 10 hr.