A distinct type of alcohol dehydrogenase, adh4+, complements ethanol fermentation in an adh1-deficient strain of Schizosaccharomyces pombe

In the fission yeast Schizosaccharomyces pombe, only one alcohol dehydrogenase gene, adh1(+), has been identified. To elucidate the influence of adh1(+) on ethanol fermentation, we constructed the adh1 null strain (Deltaadh1). The Deltaadh1 cells still produced ethanol and grew fermentatively as the wild-type cells. Both DNA microarray and RT-PCR analysis demonstrated that this ethanol production is caused by the enhanced expression of a Saccharomyces cerevisiae ADH4-like gene product (SPAC5H10.06C named adh4(+)). Since the strain lacking both adh1 and adh4 genes (Deltaadh1 Deltaadh4) showed non-fermentative retarded growth, only these two ADHs produce ethanol for fermentative growth. This is the first observation that a S. cerevisiae ADH4-like alcohol dehydrogenase functions in yeast ethanol fermentation. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.