Anaerobic carbon metabolism of saccharomyces cerevisiae

The yeast Saccharomyces cerevisiae is a facultative anaerobic organism able to grow in the absence of oxygen. Oxygenation is one of the major costs in biotechnical production processes, and the anaerobic performance of S. cerevisiae is thus attractive in the development of low-cost bioprocesses. Understanding of the carbon metabolism of S. cerevisiae in the lack of oxygen is crucial also for the optimization of oxygenated large-scale processes. Transient oxygen-depleted conditions and oxygen gradients commonly appear in large bioreactors and in high-cell density cultures due to imperfect mixing. In addition of being an industrial production organism, S. cerevisiae is an attractive model organism for studying the cell physiology and regulation under the conditions of different energetic challenges such as anaerobiosis. The observations and understanding can be translated to higher eukaryotes since many of the regulatory mechanisms are conserved within Eukaryota. It is also fascinating that there is a similarity between the anaerobic organization of the carbon metabolism of S. cerevisiae and the 'low ATP yield-high rate' energy metabolism, which is a regulatory choice and competitive advantage behind the behaviour of not only S. cerevisiae but also, for example, cancer cells. In this review, the response of the carbon metabolism of S. cerevisiae to the lack of oxygen will be discussed in the light of comprehensive data on multiple levels of cell function.