Evaluation of horA and horC as genetic markers for the determination of beer spoilage ability in lactic acid bacteria
2007
Suzuki, K.(Asahi Breweries Co. Ltd., Moriya, Ibaraki (Japan)) | Iijima, K. | Asano, S. | Kuriyama, H. | Kitagawa, Y.
Four beer spoilage strains, LA 20, LA 21, LA 22 and LA 23, were isolated from brewery environments. On the basis of the 16 S rRNA gene sequencing analysis, LA 20 was identified as Pediococcus inopinatus, and the remaining three were identified as Lactobacillus backi. The homologs of horA and horC, hop resistance genes originally identified in L. brevis ABBC 45, were detected in L. backi LA 22 and LA 23, while only a horA homolog and a horC homolog were found in LA 20 and LA 21, respectively. The 5.6 kb DNA regions containing the horA homolog and 4 other flanking open reading flames (ORFs) found in LA 20 and LA 22 were almost 99% identical with that of L. brevis ABBC 45. Similarly, the 8.2 kb regions containing the horC homolog and 6 other flanking ORFs identified in LA 21 and LA 22 were more than 99% identical with that of ABBC 45. Taken together, these results reinforce our hypothesis that horA and horC genes were acquired by beer spoilage species through horizontal gene transfer and further confirm the usefulness of horA and horC as genetic markers for the species-independent determination of beer spoilage ability in lactic acid bacteria.
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