Anabolic role of l-malic acid in Saccharomyces cerevisiae in anaerobiosis during alcoholic fermentation

Abstract

In anaerobiosis, pyruvate carboxylase activity can be greatly reduced by limiting the availability of biotin to yeast cells. In these conditions an incorporation of carbon from exogenous l-malic acid can be observed. The main pathway used for this anabolic utilization goes through malate dehydrogenase and the oxidative reactions of the tricarboxylic acid cycle. This anabolic function of l-malic acid is strongly inhibited by a residual glucose concentration in the fermenter. This inhibition may be due, in this condition, to a higher intracellular concentration of some negative effectors of malate dehydrogenase such as: 1,6-fructose diphosphate, glyceraldehyde 3-phosphate, ATP and ADP. © 1987.