Mycological and Mycotoxicological Producing Potential of Isolates from Fermented Melon Seeds [Citrullus lanatus (Thumb) Matsun ‘Egusi kirikiri’]

Abstract

This study identified and examined fungal presumed producing mycotoxins in fermented melon seed condiment (ogiri). The samples were cultured on Potato Dextrose Agar and Sabouraud Dextrose agar to identify fungi. The detection of mycotoxins in the fermented melon seeds samples was carried out by the use of Coconut Agar Media (CAM), by which the fungal isolates were cultured and plates incubated for 3-7days at 280C. The mycobiota of fermented melon seed revealed of many species belonging to the Aspergillus spp, Penicillium spp, Cladosporium spp, and Rhizopus oryzae. Among all the fungi identified in the study, Aspergillus spp has the highest prevalence rate (44.4%) while Penicillium spp, and Rhizopus oryzae have same value (22.2%).the lowest is Cladosporium spp with (11.1%) and its presence can be attributed to decaying of the samples. The results obtained show that some of the fungal isolates had the ability to produce mycotoxins. From the mycotoxin screening, only six (6) species (Aspergillus spp, and Penicillium spp) were positive (+), Cladosporium spp, and Rhizopus oryzae were negative (-). Mycotoxin contamination level varied in different market locations in which Swali Market had the highest level of mycotoxin (50%) followed by Opolo Market (33.3%) and Tombia Market (16.7%). Mycotoxigenic producing fungi and mycotoxin levels in fermented melon seed samples are public health concern. Meanwhile, the occurrence of the pathogenic fungi (Aspergillus, Penicillium, and Rhizopus) in fermented melon seed can affect its shelf life and can also cause severe health challenges.