Nucleotide Sequence Identities of horA Homologues and Adjacent DNA Regions Identified in Three Species of Beer-Spoilage Lactic Acid Bacteria
K. Suzuki 1,3, M. Sami 2, K. Ozaki 1 and H. Yamashita 1
1 Analytical Technology Laboratory and 2Fundamental Research Laboratory, Asahi Breweries Ltd., 1-21 Midori 1-chome, Moriyashi, Ibaraki, 302-0106, Japan.
3 Corresponding author. E-mail: koji.suzuki@asahibeer.co.jp
J. Inst. Brew. 110(4), 276-283, 2004 | VIEW ARTICLE
ABSTRACT
The horA homologues and adjacent DNA regions identified in beer-spoilage Lactobacillus lindneri DSM 20690T and L. paracollinoides DSM15502T were examined and compared with the corresponding DNA region of beer-spoilage L. brevis ABBC45, a strain in which the hop-resistance gene horA was originally identified. The PCR analysis suggests ORFB1-B5 regions surrounding horA are conserved in all of the strains. The nucleotide sequence comparison of the conserved DNA regions revealed extremely high levels of identities among the three beer-spoilage strains that are not typical for distinct species. The PCR methods using primers specific to the adjacent ORFs were found to be able to differentiate beer-spoilage Lactobacillus strains from non-spoilers, indicating these ORFs are also useful genetic markers for determining the beer-spoilage ability of lactobacilli. The presence or absence of the adjacent ORFs in 92 bacterial strains was completely identical with that of horA homologues, indicating the ORFB1-B5 regions are generally conserved in beer-spoilage Lactobacillus strains. Taken together, these results suggest the ORFB1-B5 regions have been acquired by beerspoilage lactobacilli through horizontal gene transfer and provide a theoretical basis for applying a trans-species genetic marker such as horA to deal with unencountered species of beerspoilage lactobacilli.
Key words:
Beer-spoilage ability, lactobacilli, horA, horizontal
gene transfer, trans-species genetic marker.
Publication no. G-2004-1230-239 ©2004 The Institute & Guild of Brewing