Factors influencing the utilisation of l-malate by yeasts

The utilisation of l-malate and the effect of glucose concentration on malate utilisation under semii-anaerobic conditions were evaluated in three yeaest unable to grow the malate as sole cabron source (Saccharomtnes cerevisea, Schhizo-sacccharomyte malidevorans, Zygosaccharomyces bailii) and two yeasts able to utilise the TCA cycle intermediate as sole carbon source (Pichia stipitis and Pachysolen tannophilus). Utilisation of malate by both Schitz. malidevorans and Z. bailii was reduced at high and low levels of glucose. In the absence of glucose, P. stipitis and Pa. tannophilus utilised malate rapidly; however, their utilisation was drastically redued in the presence of glucose, suggesting that malate utilisation is under catabolite repression.