Influence of halogen salts on the production of the ochratoxins by Aspergillus ochraceus Wilh.
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.
Stander
M A
MA
School of Chemistry and Biochemistry, University of Potchefstroom, Potchefstroom 2520, South Africa.
Steyn
P S
PS
Lübben
A
A
Miljkovic
A
A
Mantle
P G
PG
Marais
G J
GJ
D001235:Aspergillus ochraceus / Q000187:drug effects* / Q000378:metabolism; D006219:Halogens / Q000737:chemistry / Q000494:pharmacology*; D009793:Ochratoxins / Q000096:biosynthesis*; D012492:Salts
D006219:Halogens; D009793:Ochratoxins; D012492:Salts