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CHARACTERISATION OF AMYLOLYTIC BREWING YEAST
Author(s) -
Vakeria Dina,
Box Wendy,
Bird Louise,
Mellor Jane
Publication year - 1996
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1996.tb00891.x
Subject(s) - brewing , plasmid , yeast , fermentation , biology , biochemistry , saccharomyces cerevisiae , gene
Amylolytic brewing yeast can be used for the production of low carbohydrate beer and for maximizing fermentation efficiency. In this paper we describe the characterisation of amylolytic brewing yeast in which the STA2 (DEXI) gene, which codes for an extracellular glucoamylase, was cloned under two different promoters; PGK (phosphoglycerate kinase) and GPD1 (sn‐glycerol‐3‐phosphate dehydrogenase) present on episomal plasmids. Both amylolytic strains were shown to ferment and degrade wort as efficiently as the control strain supplemented with an exogenous commercial glucoamylase, despite reduced intracellular glycogen levels (30% of wild‐type). However, the nature of the promoter on the expression plasmid was shown to influence both the growth rate of the amylolytic strains and the stability of the plasmids during non‐selective growth. One of the strains containing plasmid pDVX4 ( GPD promoter) was found to show high levels of stability when tested in ten successive pilot scale (8Hlitre) fermentations.