Evaluation of carbon and nitrogen sources on fumonisin B1 production by Fusarium verticillioides in defined culture médium

Abstract

Fusarium verticillioides Sacc. Niremberg (= F. moniliforme Sheldon) is a primary corn pathogen and the main fumonisin producer. Considering that the nutrient quality and its concentration in the culture medium have an important role in fumonisin production, the aim of this study was to evaluate fumonisin B1 (FB1 ) production by F. verticillioides in a liquid culture medium with different carbon and nitrogen sources. Three strains (103F, 113B and 103BR) were inoculated in nine liquid culture media with different carbon sources (glucose, fructose and maltose) at the concentration of 20 g/L and nitrogen (leucine, alanine and valine) at the concentration of 1 g/L. After selecting the strain (103F) and carbon/nitrogen sources (maltose/leucine) that provided the highest FB1 production, culture media with different maltose and leucine concentrations were evaluated. Keeping the leucine concentration at 1 g/L and increasing the maltose concentration from 20 g/L to 40 g/L, the FB1 production increased from 3.9 ?g/mL to 4.7 ?g/mL (p < 0.05). On the other hand, keeping the maltose concentration at 40 g/L and decreasing the leucine concentration to 50% (from 2 g/L to 1 g/L) the FB1 production increased from 2.3 ?g/mL to 4.7 ?g/mL (p < 0.05). FB1 production varied according to the F. verticillioides strain, concentration and carbon/nitrogen source in the liquid culture medium and the increase in maltose concentration showed a significant positive effect (+0.6 ± 0.11), whereas the increase in leucine concentration showed a negative effect (?2.2 ± 0.11).