[Study on application of rep-PCR fingerprint in rapid identification of beer-spoilager]

The application potential of rep-PCR in typing beer-spoilage isolates was studied. The effects of different factors, including DNA templates and primers, on the quality and reproducibility of fingerprints were investigated. The CTAB protocol was shown to be the feasible method for DNA extraction. Primers BOXA1R and (GTG)5 were used in rep-PCR, and the PCR products were sequenced to identify strains isolated from two breweries. Rep-PCR fingerprint profiles were obtained by using GelCompar II software. Cluster analysis showed that the isolates belonging to Lactobacillus brevis, L. buchneri, L. casei/paracasei, L. plantarum are divided into 2 or 3 subgroups. In addition, the two rep-PCR fingerprint profiles complemented with each other in typing these isolates. Combining the similarity coefficient cut-off (SCC) of species, 9 unknown isolates were identified rapidly by using both fingerprint databases. The results indicate that rep-PCR is a simple, reliable and promising method for rapid identification of beer-spoilager.