Study of the Effect of Methyl Jasmonate Concentration on AflatoxinB1Biosynthesis byAspergillus parasiticusin Yeast Extract Sucrose Medium

Abstract

AflatoxinB1(AFB1) is a carcinogenic metabolite produced by certainAspergillusspecies on agricultural commodities. AFB1biosynthesis is affected by jasmonic acid and also by its methylester (MeJA), a plant growth regulator derived from linoleic acid. This study reports the effect of MeJA on the growth ofA. parasiticusand AFB1output in yeast extract sucrose (YES) medium when added at three different concentrations; namely,10−2 M,10−4 M, and10−6 M. AFB1determination was performed by immunoaffinity and HPLC. MeJA at10−4and10−6M concentrations had no significant effect on mycelial growth but did affect AFB1production after the 7th day of incubation; on the 12th day, AFB1production was increased by 212.7% and 141.6% compared to the control samples (addition of10−6 M and10−4 M MeJA, resp.). Treatment ofA. parasiticuscultures with10−2 M MeJA inhibited mycelial growth and AFB1production as well. These results suggest that the effect of MeJA on AFB1biosynthesis byA. parasiticusdepends on the MeJA concentration used.