CHROMOSOMAL INTEGRATION AND EXPRESSION OF 2 BACTERIAL ALPHA-ACETOLACTATE DECARBOXYLASE GENES IN BREWERS-YEAST

K BLOMQVIST, ML SUIHKO, J KNOWLES, Merja Penttilä

Research output: Contribution to journalArticleScientificpeer-review

Abstract

A bacterial gene encoding alpha-acetolactate decarboxylase, isolated from Klebsiella terrigena or Enterobacter aerogenes, was expressed in brewer's yeast. The genes were expressed under either the yeast phosphoglycerokinase (PGK1) or the alcohol dehydrogenase (ADH1) promoter and were integrated by gene replacement by using cotransformation into the PKG1 or ADH1 locus, respectively, of a brewer's yeast. The expression level of the alpha-acetolactate decarboxylase gene of the PGK1 integrant strains was higher than that of the ADH1 integrants. Under pilot-scale brewing conditions, the alpha-acetolactate decarboxylase activity of the PGK1 integrant strains was sufficient to reduce the formation of diacetyl below the taste threshold value, and no lagering was needed. The brewing properties of the recombinant yeast strains were otherwise unaltered, and the quality (most importantly, the flavor) of the trial beers produced was as good as that of the control beer.

Original languageEnglish
Pages (from-to)2796-2803
Number of pages8
JournalApplied and Environmental Microbiology
Volume57
Issue number10
Publication statusPublished - Oct 1991
MoE publication typeA1 Journal article-refereed

Keywords

  • CONSTRUCTION
  • CLONING

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