Abstract

In this study, the effect of different concentrations of L-phenylalanine (0, 0.10, 0.25, 0.50, 1 and 2 mM) was used as a precursor to enhance antifungal natural product strobilurin A, which was investigated in the fungus Strobilurus tenacellus. The putative precursor was added to the fungal shake flask culture and the concentration of strobilurin A was quantified by liquid chromatography and mass spectroscopy (LCMS). The concentrations of the feeding flasks were compared with the control culture under similar conditions of fermentation. Highest yield (2.5 times higher than control) was observed in the flasks fed with 1 mM of L-phenylalanine. This supports the hypothesis that L-phenylalanine is the putative precursor of strobilurin A and during biosynthesis probably, the aromatic part of the compound is derived from this precursor.

Key words: Strobilurin A, Strobilurus tenacellus, phenylalanine precursor.