Secondary metabolites of Fusarium venenatum strains with deletions in the Tri5 gene encoding trichodiene synthetase

We studied the secondary metabolites of a number of strains of F. venenatum , some of which had the gene for trichodiene synthetase deleted. Under opti mum fermentation conditions, wild type isolates produced the trichothecenes diacetoxyscirpenol and related metabolites, isotrichodermin and isotricode rmol, the modified trichothecenes sambucinol and apotrichothecene, the sesq uiterpenes culmorin and culmorone and derivatives and trace amounts of the cyclic peptide enniatin B. These results are compared to metabolite product ion by other members of the section Discolor. Strains without trichodiene s ynthetase produced no trichothecenes or modified trichothecenes. In these s trains, production of culmorin family compounds was greatly attenuated desp ite the elimination of an acetate-derived biosynthetic pathway. This was co ntrary to expectations. No other metabolites were produced by these strains evidenced by chemical or cytotoxicity analyses of fractionated extracts.