The Contribution of Taxonomists to the Understanding of Yeast Nutrition
J. A. Burnett
School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, England
Article history:
Received September 10, 1997
Accepted November 21, 1997
Key words:
Yeast taxonomy and nutrition, sugar catabolism
Summary:
Taxonomists make important and unique contributions to comparative biology by describing large numbers of organisms in detail. Such comparative observations have stimulated research on the physiology and biochem¬istry of yeast nutrition. Three examples follow. (1) From fermentation tests of Stelling-Dekker, Kluyver concluded tlial no yeast ferments any sugar unless it ferments glucose and all yeasts that ferment glucose also ferment fructose and mannose, Kluyver made these generalizations in 1931, but the biochemical explanations for them were not fully understood until years later, when the main reactions of phosphorylated sugars and their derivatives in glycolysis were elucidated. (2) Results of aerobic growthtests, by van Uden and Kreger-van Rij, indicated the pathways by which yeasts calabolize pentoses, such as D-xylose, and h-arabinose, (3) Current research on the mechanism of the Kluyver effect, first described in one or two species in 1940, has followed from analysing the results of taxonomists' groiuth and fermentation tests. These showed the effect to occur in about 20% of yeast species and to apply to glycosides that are hydrolysed in the cytosol and have throiun light on the encrg}/ requirements of glycoside uptake. Accordingly, research workers concerned with the biology, physiology and biochemistry of yeasts, for academic or commercial reasons, should ensure the continuance and improvement of nutritional testing by yeast taxonomists.