title: Influence of halogen salts on the production of the ochratoxins by Aspergillus ochraceus Wilh.
abstract: The first report of the biological production of bromo ochratoxin B by Aspergillus ochraceus Wilh. is presented as well as a study of the influence of potassium bromide, potassium iodide, potassium fluoride, and potassium chloride on the production of ochratoxin A and ochratoxin B. Potassium fluoride and potassium iodide inhibited the growth of the fungus, whereas potassium chloride substantially stimulated the production of ochratoxin A in shaken solid substrate fermentation on whole wheat or shredded wheat, generally giving a high yield of ochratoxins. Increasing levels of potassium bromide led to a decline in ochratoxin A production and an increase in bromo-ochratoxin B, ochratoxin B, and 4-hydroxy ochratoxin B. Nevertheless, A. ochraceus was much less versatile in the bromo analogues than other fungi, which produce metabolites containing chlorine. Analysis included aminopropyl solid-phase extraction column cleanup followed by quantitative analysis on reversed-phase HPLC using fluorescence detection and employing N-(5-chloro-2-hydroxybenzoyl)phenylalanine as an internal standard.
authors.affiliation: School of Chemistry and Biochemistry, University of Potchefstroom, Potchefstroom 2520, South Africa.
authors.forename: M A
authors.initials: MA
authors.lastname: Stander
authors.forename: P S
authors.initials: PS
authors.lastname: Steyn
authors.forename: A
authors.initials: A
authors.lastname: Lübben
authors.forename: A
authors.initials: A
authors.lastname: Miljkovic
authors.forename: P G
authors.initials: PG
authors.lastname: Mantle
authors.forename: G J
authors.initials: GJ
authors.lastname: Marais
mesh_terms: D001235:Aspergillus ochraceus / Q000187:drug effects* / Q000378:metabolism; D006219:Halogens / Q000737:chemistry / Q000494:pharmacology*; D009793:Ochratoxins / Q000096:biosynthesis*; D012492:Salts
chemical_list: D006219:Halogens; D009793:Ochratoxins; D012492:Salts