Diversity and toxigenicity of fungi and description of sp. nov. from cereals, legumes and soils in north-central Nigeria.

Mycological investigation of various foods (mainly cowpea, groundnut, maize, rice, sorghum) and agricultural soils from two states in north-central Nigeria (Nasarawa and Niger), was conducted in order to understand the role of filamentous fungi in food contamination and public health. A total of 839 fungal isolates were recovered from 84% of the 250 food and all 30 soil samples. Preliminary identifications were made, based on macro- and micromorphological characters. Representative strains (n = 121) were studied in detail using morphology and DNA sequencing, involving genera/species-specific markers, while extrolite profiles using LC-MS/MS were obtained for a selection of strains. The representative strains grouped in seven genera (, , , , , and ). Amongst the 21 species that were isolated during this study was one novel species belonging to the species complex, , obtained from groundnut and sorghum in Nasarawa state. The examined strains produced diverse extrolites, including several uncommon compounds: averantinmethylether in ; aspergillimide in ; heptelidic acid in ; desoxypaxillin, kotanin A and paspalitrems (A and B) in , and ; aurasperon C, dimethylsulochrin, fellutanine A, methylorsellinic acid, nigragillin and pyrophen in ; cyclosporins (A, B, C and H) in ; methylorsellinic acid, pyrophen and secalonic acid in ; aspulvinone E, fonsecin, kojic acid, kotanin A, malformin C, pyranonigrin and pyrophen in ; and all compounds in sp. nov., , and . This study provides snapshot data for prediction of food contamination and fungal biodiversity exploitation.