Ecological and toxicological importance of fungal diversity in pastures and potential role for novel Fusarium species in cattle mycotoxicosis

<p dir="ltr">The datasets underpinned a PhD thesis titled "The mycobiota of Eastern Cape dairy pastures, including the characterisation and implications of novel Fusarium species." The researcher surveyed fungal communities in mixed pasture samples from 14 affected dairy farms. From 95 samples, 708 fungal strains were isolated and identified as 132 species across 55 genera. Fusarium was the most prevalent genus (207 strains; 21 species), followed by Penicillium, Pseudopithomyces, Cladosporium, Epicoccum, and Bipolaris. Notably, phylogenetic analyses confirmed the presence of both Pseudopithomyces toxicarius (previously reported as Pseudopithomyces chartarum) and Ps. palmicola. Among Fusarium, 155 strains belonged to the Fusarium incarnatum-equiseti species complex (FIESC). Multilocus phylogenetic analyses of TEF1-α, CaM, and RPB2 genes revealed 11 FIESC species, including five novel taxa, three of which—F. cumulatum, F. mariecurieae, and F. pascuum—researchers formally described, along with a description of F. goeppertmayerae. The researcher further examined the secondary metabolite potential of these four Fusarium species using chemical and bioinformatics-based approaches, identifying 16 secondary metabolites. From these secondary metabolites, three were identified as regulated mycotoxins (deoxynivalenol, nivalenol, and zearalenone) and nine as emerging mycotoxins (e.g., beauvericin, diacetoxyscirpenol, and equisetin). As part of the investigation into secondary metabolite potential, several core biosynthetic genes were identified, including some not associated with detectable metabolite production in vitro, highlighting the genetic capacity of these species to produce these compounds under favourable conditions.</p>