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A mathematical model of glycolysis in Saccharomyces cerevisiae is presented. The model is based on rate equations for the individual reactions and aims to predict changes in the levels of intra- and extracellular metabolites after a glucose pulse, as described in part I of this study. Kinetic analysis focuses on a time scale of seconds, thereby neglecting(More)
Transition from glucose limitation to glucose excess in Saccharomyces cerevisiae leads to a fast change from complete to partial oxidative metabolism. To determine rapid changes of in vivo concentrations of yeast metabolites, occurring in the range of seconds after a glucose injection, a fast sampling technique was developed. A harvesting device with(More)
Gallidermin production by Staphylococcus gallinarum was optimal using a new developed medium consisting of 50 g yeast extract l−1, 45 g CaCl2 l−1 and 5 g maltose l−1. Medium optimisation led to the cost of the medium decreasing by 93% compared to the previously used medium and in addition gained a higher product yield. A scale-up of the process based on the(More)
The goal of this work was to obtain rapid sampling technique to measure transient metabolites in vivo. First, a pulse of glucose was added to a culture of the yeast Saccharomyces cerevisiae growing aerobically under glucose limitation. Next, samples were removed at 2 to 5 s intervals and quenched using methods that depend on the metabolite measured.(More)
The cultivation of strains of the genus Streptosporangium in batch fermentations demonstrated that the optimal conditions for secondary metabolite production are completely different to those of the closely related genus Streptomyces. The dissolved oxygen tension (pO(2)) was identified as an important parameter for optimal production of secondary(More)
Streptomyces antibioticus Tü 6040 is the producer of simocyclinones, which belong to a novel family of angucyclinone antibiotics some of which show antitumor activities. Growth and antibiotic production is dependent on the medium composition, especially on the carbon and nitrogen source, and on the fermentation conditions. The best results with respect to(More)
Decreased O supply during the fermentative production of gallidermin by Staphylococcus gallinarum decreased biomass formation by 65% compared to that obtained with optimal oxygen supply. However the antibiotic, gallidermin, increased by more than 50% at the same time. This effect was used in a process strategy, that allows biomass formation under oxygen(More)
The correlation between the consumption of amino acids and the production of the polypeptide antibiotic gallidermin by Staphylococcus gallinarum Tü 3928 was investigated by on-line determination of amino acids and pulse experiments. A prolonged production phase together with an increase in gallidermin formation of about 25% was obtained during pulse and(More)
A scale-up strategy into 200 l pilot-scale for the production of the antibiotic gallidermin by Staphylococcus gallinarum Tü 3928 was developed. Large-scale fermentations were simulated by consecutive liquid cultures of smaller scale. Afterwards, optimised cultivation conditions were transferred to pilot-scale. Best results were achieved by addition of(More)
The glycerol-3-phosphate dehydrogenase has been purified from Saccharomyces cerevisiae 140-fold to electrophoretic homogeneity by a simple procedure involving affinity and ion exchange chromatography. The purified enzyme was most active at pH 6.8 and 51 degrees C. Its molecular mass was determined to be 45000 +/- 2000 Da by SDS-polyacrylamide gel(More)