Open AccessNitrogen repression of fumonisin B1 biosynthesis in Gibberella fujikuroi
Author(s) -
Shim WonBo,
Woloshuk Charles P
Publication year - 1999
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1999.tb13720.x
Subject(s) - fumonisin , gibberella fujikuroi , fumonisin b1 , biosynthesis , mycotoxin , ammonium , phosphate , biochemistry , food science , chemistry , metabolite , metabolism , biology , fusarium , botany , enzyme , organic chemistry
Fumonisins are a group of structurally related mycotoxins produced by Gibberella fujikuroi . The fungus produced fumonisin B1 (FB1) as early as 18 hour in a defined medium containing 1.25 mM or 2.5 mM ammonium phosphate, whereas fumonisin B1 production was repressed for 75 hour and 125 hour when mycelia were resuspended in media containing ammonium phosphate at 10 mM or 20 mM, respectively. Although total fumonisin B1 production was greater in resuspension cultures grown in higher concentrations of ammonium phosphate, the accumulation was independent of the inoculum size and carbon/nitrogen ratio. The addition of ammonium phosphate to cracked corn cultures also repressed fumonisin B1 production by 97%, and persisted for at least three weeks. Thus, biosynthesis of fumonisin B1 is regulated by a mechanism involving nitrogen metabolite repression, suggesting that control strategies that target the regulatory elements of nitrogen metabolism may be effective at reducing the risk of fumonisin contamination in food.