title: Production of(14)C-ochratoxin A byPenicillium verrucosum sp. 1761 in liquid culture.
abstract: The synthesis of(14)C-labelled ochratoxin A was carried out by biosynthesis withPénicillium verrucosum sp. 1761 in liquid culture using 2-(14)C-Na-acetate and 2-(14)C-malonic acid as precursor. The largest amount of ochratoxin A produced byPénicillium verrucosum was detected in a minimal medium after an incubation period of 28 days. By addition of citric acid and 2,4-dichlorophenoxy acetic acid larger ochratoxin A contents could be measured. For transformation studies of ochratoxin A, a molecule which is exclusively labelled in the isocoumarin moiety is best suitable. This labelling could be obtained by using labelled malonic acid as precursor, whereas with 2-(14)C-Na-acetate as precursor the whole molecule was labelled. Incorporation rates of radioactivity into the molecule were from 0.04% to 0.11%, specific radioactivities from 0.02 μCi/mg to 0.07 μCi/mg.
authors.affiliation: Bayerische Landesanstalt für Ernährung, Menzingerstr. 54, 80638, München, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Ruhland
authors.forename: G
authors.initials: G
authors.lastname: Engelhardt
authors.forename: P R
authors.initials: PR
authors.lastname: Wallnöter