Trehalose accumulation in Saccharomyces cerevisiae cells:: experimental data and structured modeling

Several studies have shown that the reserve disaccharide trebalose also protects yeast cells under environmental stress. Besides, it is acknowledged that trehalose improves yeast viability so its synthesis has become paramount in baker's yeast industry, as well as in wine and beer production. In this work, starving carbon or nitrogen conditions were imposed to Saccharomyces cerevisiae growing in fed-batch cultivations in order to induce biosynthesis and accumulation of trehalose. Our experimental results show that yeast can accumulate trehalose up to 13% of biomass dry weight (0.13 g(trehalose) g(biomass)(-1)) under carbon or nitrogen starvation. A compartmentalized and biochemically structured model is proposed in order to mathematically describe these experimental findings. The model predictions were compared with literature results obtained under growth conditions different from those established in our experiments, resulting in a very good agreement and thus indicating that the proposed hypotheses are essentially correct. (C) 2003 Elsevier B.V. All rights reserved.