Abstract
The hop-tolerance gene horA frequently found in
beer-spoilage lactic acid bacteria (LAB) was investigated
for sequence variability. Although the horA gene was
found to have less sequence variability relative to the
LAB hop-tolerance gene horC, a sequence insertion in horA
in some isolates resulted in early truncation of HorA
translation. This truncated HorA was found in LAB both
capable and incapable of growth in beer. Protein modeling
revealed that the truncated HorA may retain some capacity
to bind and sequester hop iso-a-acids but lacks the
transport function essential for moving hop compounds out
of the cell. Sequence analysis of LAB plasmids that
contain horA revealed a high level of conservation in all
of the genes comprising the horA gene cassette. Assessing
whether a LAB isolated in a brewery setting is capable of
making a full-length protein with intact hop transport
function or a truncated HorA requires redesign of
commonly used horA polymerase chain reaction primers to
target detection of horA both with and without the
sequence insertion.
Original language | English |
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Pages (from-to) | 339-344 |
Journal | Journal of the American Society of Brewing Chemists |
Volume | 75 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2017 |
MoE publication type | A1 Journal article-refereed |
Keywords
- gene variance
- hop-tolerance gene
- horA
- lactic acid bacteria
- lactobacillus
- pediococcus
- protein modeling