High-throughput isolation of bacteriocin-producing lactic acid bacteria, with potential application in the brewing industry

Lactic acid bacteria (LAB) were isolated from malted cereals by means of a high-throughput screening approach and investigated for antimicrobial activity against a range of beer-spoiling bacteria. Putative bacteriocin-producing strains were identified by 16S rRNA analysis and the inhibitory compounds were partially characterized. Following determination of the inhibitory spectra of the strains, an unspeciated Lactobacillus sp. UCC128, with inhibitory activity against a range of beer-spoiling strains was subjected to further characterization. A bacteriocin was purified from this strain and analyzed by mass spectrometry to determine the weight of the protein. The result indicated that the bacteriocin was highly similar to pediocin AcH/PA-1 from Pediococcus acidilactici. The bacteriocin-producers identified in this study have the potential to be used in the brewing industry to enhance the microbiological stability of beer in conjunction with hurdles already in place in the brewing process.