Phenotype variability makes it difficult to speciate Pediococcus isolates. Through phylogenetic analyses, we recently determined that the genus Pediococcus contains six taxonomic groupings, including a new species. The goal of the current study was to determine whether immunoblotting would parallel our phylogenetic results and to establish whether immunoblotting can be used as a phenotypic method for isolate identification. Thirty-one Pediococcus isolates, most of brewing origin, were analyzed by immunoblots using polyclonal antisera generated in mice or rabbits against various Lactobacillus and Pediococcus isolates. Comprehensive immunoblot patterns were obtained with two antisera, and survey immunoblot patterns for one isolate from each phylogenetic group were obtained with 10 antisera. Inspection of the survey immunoblots revealed a unique banding pattern for the isolate representing each phylogenetic group. The profiles depended on the phylogenetic group of the isolate and the antisera used. For the four phylogenetic groups for which we had at least five isolates each, computer-based analysis of the comprehensive immunoblots readily distinguished each group. The results show that isolates identified phylogenetically as P. acidilactici, P. damnosus, P. pentosaceus, and the new Pediococcus species, P. claussenii, are readily identified by immunoblotting.
Journal of the American Society of Brewing Chemists / Vol. 60, No. 4, pp.170-175