Molecular responses of Saccharomyces cerevisiae to near-zero growth rates

Dynamics of Storage Carbohydrates Metabolism in Saccharomyces cerevisiae

Production of chemicals via biotechnological routes are becoming rapidly an alternative to oil-based processes. Several microorganisms including yeast, bacteria, fungi and algae can transform feedstocks into high-value molecules at industrial scale. Improvement of the bioprocess performance is a key factor for making this technology economically...

Engineering precursor supply in Saccharomyces cerevisiae: New strategies for cytosolic acetyl-CoA formation

Metabolic engineering – the improvement and addition, by genetic modification, of industrially relevant properties of microorganisms with respect to catalysis, transport and regulatory functions – is a well-established method for development of more cost-effective and ‘green’ industrial processes. Rapid depletion of oil reserves and a growing...

Functional expression of a heterologous nickel-dependent, ATP-independent urease in Saccharomyces cerevisiae

In microbial processes for production of proteins, biomass and nitrogen-containing commodity chemicals, ATP requirements for nitrogen assimilation affect product yields on the energy producing substrate. In Saccharomyces cerevisiae, a current host for heterologous protein production and potential platform for production of nitrogen-containing...

Transport of Dicarboxylic Acids in Saccharomyces cerevisiae

Novel strategies for engineering redox metabolism in Saccharomyces cerevisiae

In its search to decrease the environmental impact of the production of materials and food, and for other socio-economic reasons, mankind has recently taken the first steps into a paradigm shift from a petrochemical-based society to a new, sustainable and to a significant extent bio-based society. In this new scenario, biomass derived from...

Towards fermentation of galacturonic acid-containing feedstocks with Saccharomyces cerevisiae

The ambition to reduce our current dependence on fossil transportation fuels has driven renewed interest in bioethanol. Pectin-rich feedstocks like sugar beet pulp and citrus peel, which are currently sold as cattle feed, are promising raw materials for the production of bioethanol. This thesis explores the challenges related to the fermentation...

Carbon dioxide fixation by Calvin-Cycle enzymes improves ethanol yield in yeast

Background Redox-cofactor balancing constrains product yields in anaerobic fermentation processes. This challenge is exemplified by the formation of glycerol as major by-product in yeast-based bioethanol production, which is a direct consequence of the need to reoxidize excess NADH and causes a loss of conversion efficiency. Enabling the use of...

amdSYM, a new dominant recyclable marker cassette for Saccharomyces cerevisiae

Despite the large collection of selectable marker genes available for Saccharomyces cerevisiae, marker availability can still present a hurdle when dozens of genetic manipulations are required. Recyclable markers, counterselectable cassettes that can be removed from the targeted genome after use, are therefore valuable assets in ambitious...

Metabolic engineering of free-energy (ATP) conserving reactions in Saccharomyces cerevisiae

Metabolic engineering – the improvement of cellular activities by manipulation of enzymatic, transport and regulatory functions of the cell – has enabled the industrial production of a wide variety of biological molecules from renewable resources. Microbial production of fuels and chemicals thereby provides an alternative to oil-based production...

Cellular responses of Saccharomyces cerevisiae at near-zero growth rates: Transcriptome analysis of anaerobic retentostat cultures

Extremely low specific growth rates (below 0.01 h?1) represent a largely unexplored area of microbial physiology. In this study, anaerobic, glucose-limited retentostats were used to analyse physiological and genome-wide transcriptional responses of Saccharomyces cerevisiae to cultivation at near-zero specific growth rates. While quiescence is...

Physiology and robustness of Saccharomyces cerevisiae at near-zero specific growth rates

Generic and specific transcriptional responses to different weak organic acids in anaerobic chemostat cultures of Saccharomyces cerevisiae.

Transcriptional responses to four weak organic acids (benzoate, sorbate, acetate and propionate) were investigated in anaerobic, glucose-limited chemostat cultures of Saccharomyces cerevisiae. To enable quantitative comparison of the responses to the acids, their concentrations were chosen such that they caused a 50% decrease of the biomass...