Isolation and characterization of fungi isolated from Nigerian cocoa samples

Ten fungal isolates were cultured from 40 samples of powdered cocoa by plating on Potato Dextrose Agar and incubation at 25^oC for 7 days. They were subjected to macro- and micro-morphological examination to determine their genus and species. Some of the identified fungal species have been reported to produce industrially important enzymes, which they utilize to degrade a wide variety of substrates, while others have been reported to produce mycotoxins and also incite diseases in humans and animals. For the fungi identified, those that had the potential to produce mycotoxins were then analyzed using thin layer chromatography as well as ultra-pure liquid chromatography. Finally, we performed molecular analyses for our fungal isolates, to confirm or refute their morphological identifications, by amplifying and sequencing a portion of their respective ITS regions. Our findings supported most of the morphological identifications, but there were some observed inconsistencies based on mycotoxin and molecular examinations. Our findings underscore the importance of a multi-faceted approach to fungal identification. The following six genera or species were distinctly identified from the isolates: Aspergillus flavus, A. niger, A. tamarii, A. violaceofuscus, Neocosmospora ramosa and Syncephalastrum racemosum. The availability of these fungal isolates will serve as a reference point for researchers in southwestern Nigeria, thereby improving the quality and integrity of cocoa research in this region.