Production of type A trichothecenes and enniatin B by Fusarium sambucinum Fuckel sensu lato.

Twenty-nine Fusarium isolates, representing three new taxa originated by Nirenberg from F. sambucinum Fuckel sensu lato, namely: F. sambucinum Fuckel sensu stricto, F. venenotum Nirenb., and F. torulosum (Berk. & Curt.) Nirenb., were tested for in vitro production of toxic secondary metabolites on autoclaved corn kernels. F. sambucinum sensu stricto was able to produce type A trichothecenes and enniatin B (EB). In particular, amongst the 14 isolates tested, 5 produced only diacetoxyscirpenol (DAS) (up to 700 micrograms/g); 1 produced only neosolaniol (NEOS) (250 micrograms/g); 2 produced T-2 toxin (T-2) + NEOS (up to 175 and 150 micrograms/g, respectively); 1 produced NEOS + DAS (300 and 100 micrograms/g, respectively); and 5 produced DAS + EB (up to 500 and 140 micrograms/g, respectively). All six isolates of F. venenotum were able to produce only DAS (up to 100 micrograms/g). F. torulosum produced no trichothecenes, but four out of nine tested isolates were able to produce EB (up to 140 micrograms/g). Zearalenones and type B trichothecenes were not found. The toxicity of the culture extracts towards Artemia salina L. was correlated in general with the occurrence of the above toxins, except for some F. torulosum strains. However, the lack of correlation between the amounts of toxins recovered and toxic activity observed in the Geotrichum candidum Link ex Pers. and A. salina assays suggested the presence of unknown toxic compounds.