Uncoupling yeast growth and product formation in chemostat and retentostat cultures

The progress of modern biotechnology has enabled the development of fermentation processes for the production of fuels and chemicals from renewable feedstocks. The current fermentation processes for bio-based production commonly start with a growth phase of the microorganisms followed by a production phase. This implies that biomass formation...

Anaerobic growth of Saccharomyces cerevisiae CEN.PK113-7D does not depend on synthesis or supplementation of unsaturated fatty acids

In Saccharomyces cerevisiae, acyl-coenzyme A desaturation by Ole1 requires molecular oxygen. Tween 80, a poly-ethoxylated sorbitan-oleate ester, is therefore routinely included in anaerobic growth media as a source of unsaturated fatty acids (UFAs). During optimization of protocols for anaerobic bioreactor cultivation of this yeast, we...

Metabolic switches from quiescence to growth in synchronized Saccharomyces cerevisiae

Introduction: The switch from quiescence (G0) into G1 and cell cycle progression critically depends on specific nutrients and metabolic capabilities. Conversely, metabolic networks are regulated by enzyme–metabolite interaction and transcriptional regulation that lead to flux modifications to support cell growth. How cells process and...

DNA sequence encodes the position of DNA supercoils

The three-dimensional organization of DNA is increasingly understood to play a decisive role in vital cellular processes. Many studies focus on the role of DNA-packaging proteins, crowding, and confinement in arranging chromatin, but structural information might also be directly encoded in bare DNA itself. Here, we visualize plectonemes ...

Characterisation of the broad substrate specificity 2-keto acid decarboxylase Aro10p of Saccharomyces kudriavzevii and its implication in aroma development

Background: The yeast amino acid catabolism plays an important role in flavour generation since higher alcohols and acetate esters, amino acid catabolism end products, are key components of overall flavour and aroma in fermented products. Comparative studies have shown that other Saccharomyces species, such as S. kudriavzevii, differ during...

CRISPR/Cas9: A molecular Swiss army knife for simultaneous introduction of multiple genetic modifications in Saccharomyces cerevisiae

A variety of techniques for strain engineering in Saccharomyces cerevisiae have recently been developed. However, especially when multiple genetic manipulations are required, strain construction is still a time-consuming process. This study describes new CRISPR/Cas9-based approaches for easy, fast strain construction in yeast and explores their...

Temperature impact on yeast metabolism: Insights from experimental and modeling approaches

Temperature is an environmental parameter that greatly affects the growth of microorganisms, due to its impact on the activity of all enzymes in the network. This is particularly relevant in habitats where there are large temperature changes, either daily or seasonal. Understanding how organisms have adapted to cope with these temperature-cycles...

Short term step responses of central carbon and storage metabolism in Saccharomyces cerevisiae: novel minibioreactors and 13C studies

Leakage-free rapid quenching technique for yeast metabolomics

Accurate determination of intracellular metabolite levels requires reliable, reproducible techniques for sampling and sample treatment. Quenching in 60% (v/v) methanol at ?40°C is currently the standard method for sub-second arrest of metabolic activity in microbial metabolomics but there have been contradictory reports in the literature on...