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Updated: May 27, 2026

A Tandem Liquid Chromatography–Mass Spectrometry-based Approach for Metabolite Analysis of Staphylococcus aureus
Published on: March 28, 2017
Effect of ascorbate, nitrate and nitrite on the amount of flavour compounds produced from leucine by Staphylococcus
Pelle Thonning Olesen1, Louise Heller Stahnke, Régine Talon
1BioCentrum-DTU, Technical University of Denmark, Søltofts plads, build. 221, DK-2800 Kgs. Lyngby, Denmark.
Abstract:
Resting cells of Staphylococcus xylosus and S. carnosus were incubated with ascorbate, nitrate and nitrite in defined reaction medium and their degradation of (3)H-labelled leucine into methyl-branched catabolites were studied using HPLC/radiometric detection. The experiments were carried out with and without addition of α-ketoglutarate. The main catabolic product of leucine degradation was 3-methylbutanoic acid but also small amounts of α-hydroxy isocaproic acid were produced. Nitrite addition lowered the concentration of 3-methylbutanoic acid for both Staphylococcus species and this effect was strongly amplified by ascorbate for S. xylosus but not for S. carnosus. For both species ascorbate alone had little if any effect. Also nitrate lowered the concentration of 3-methylbutanoic acid for S. xylosus. The concentration of α-hydroxy isocaproic acid was, however, increased by addition of nitrite and nitrate for S. xylosus. Addition of α-ketoglutarate generally increased the concentration of 3-methylbutanoic acid for both S. xylosus and S. carnosus.
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