Production of type A trichothecenes and enniatin B byFusarium sambucinum Fuckel sensu lato

Abstract

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.

Scientific information on mycotoxins and natural plant toxicants

“…It may not be considered as an output adopted by EFSA. EFSA reserves its rights, view and position as regards the issues addressed and the conclusions reached in the present document, without prejudice to the rights of the authors Hussein et al, 1991Mulè et al, 1992Altomare et al, 1995Ellner , 2002Thrane and Hansen, 1995Beremand et al, 1991Desjardins and Plattner, 1989Desjardins and Plattner, 1989Lauren et al, 1992Latus-Zietkiewicz et al, 1995Latus-Zietkiewicz et al, 1995Jelen et al, 1995Steyn et al, 1978 …”

Molecular Phylogenetic, Morphological, and Mycotoxin Data Support Reidentification of the Quorn Mycoprotein Fungus asFusarium venenatum

“…Strain NRRL 22198 (ϭ BBA 64478) of F. venenatum, a known producer of the type A trichothecene diacetoxyscirpenol (DAS; Altomare et al, 1995;Schmidt et al, 1995;Thrane and Hansen, 1995), was used as a positive control. The negative control consisted of a rice culture inoculated with 5 ml of sterile distilled water.…”

Tri16Is Required for Esterification of Position C-8 during Trichothecene Mycotoxin Production byFusarium sporotrichioides

“…Wild-type strains F. sporotrichioides NRRL 3299, G. pulicaris (F. sambucinum) R-6380, and Gibberella zeae (Fusarium graminearum) GZ3639 have been described previously (6,9). The wild-type strains were maintained on V8 juice agar (200 ml of V8 juice, 3 g of CaCO 3 , and 20 g of agar per liter), while transformant strains were maintained on V8 juice agar plus 300 g of hygromycin B (Calbiochem, La Jolla, Calif.) per ml. Standard light and temperature conditions were used for growth of strains on V8 juice agar slants and plates (23).…”

“…All five of these trichothecenes, except DAS, result from a hydroxylation at position C-8 and, with the exception of NEO, a subsequent esterification at C-8-OH and therefore differ from one another only at the C-8 position. Some isolates of Gibberella pulicaris also possess the ability to synthesize NEO, 8-acetylneosolaniol (8-Ac-NEO), and/or T-2 toxin, in addition to DAS (3,30). Despite a well-characterized biosynthetic pathway for type A trichothecenes (12) and the fact that most of the identified trichothecene (Tri) genes constitute a large gene cluster (10,17), the gene required for the esterification reaction at C-8 has not been identified.…”