Daniel Vollbrecht

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1. The influence of varying amounts of amino acids on the uptake of threonine, isoleucine, valine and leucine and their degradation to higher alcohols was investigated using a mutant strain of Saccharomyces cerevisiae, mating type a, genetic markers ade2, hom2, thr4, ilv2, leu1. 2. The cell mass is increased by increasing concentrations of threonine,(More)
In a randomized placebo controlled parallel double blind study on 40 patients suffering from venous edema in chronic deep vein incompetence, the edema-reducing effect of horse chestnut seed extract vs. placebo, being the main test variable, was demonstrated by hydroplethysmography to be statistically significant. In addition, measurements of leg volume(More)
D(−)-3-hydroxybutanoic acid was produced by a double mutant of Alcaligenes eutrophus, unable to synthesize poly-3-hydroxybutanoic acid and to utilize 3-hydroxybutanoate as a substrate. About 3.4 g of 3-hydroxybutanoate/l were produced under optimum conditions at pH 7.0 to 7.3, at a temperature of 30°C after exhaustion of ammonia and at restricted aeration(More)
The effect of oxygen supply on the formation of metabolites by Escherichia coli K12, Enterobacter aerogenes and Brevibacterium lactofermentum was studied. The relative respiration rate (i.e. the ratio, in percent, of the respiration rate during the production phase to that at the end of exponential growth phase) was taken as a measure of cell response to(More)
The excretion of metabolites by 48 wild-type and mutant strains belonging to various species and genera of aerobic hydrogen-oxidizing bacteria was studied. The cells were grown autotrophically and heterotrophically, and samples were analyzed by gas chromatrographic techniques. The following metabolites were identified and quantitatively determined: acetate,(More)
The chemical structure of the indometacin molecule was systematically modified with the aim of producing a substance with increased anti-inflammatory activity and improved tolerance. In addition to the variations of the methylene group of the indole-3-acetic acid and substituents on the indole nucleus of indometacin, particular attention was paid to the(More)
The effects of the aeration rate, the pH value, the temperature of the culture medium and of the age of cells on the excretion of metabolites by mutant strains of Alcaligenes eutrophus were studied. With lactate or gluconate as substrates, ethanol, 3-hydroxybutanoate, succinate, cis-aconitate, 2-oxo-3-methylbutanoate and 2-oxoglutarate were excreted, each(More)