Induction of biodeterioration on vegetables by three fungal species

Abstract

The effect of three fungal species on the nutrient profile of onions and cucumbers was studied. The species identities of the fungal isolates were initially determined based on macro- and micro-morphological characters as well as molecular confirmation, using the internal transcribed spacer region. The isolates were confirmed as Neocosmospora ramosa (MG682504), Aspergillus tamarii (MG682505) and A. violaceofuscus (MG682503). We then used each fungus to induce biodeterioration and performed proximate analysis of nutrient breakdown. We also assayed each fungus for the production of mycotoxins and performed anti-fungal susceptibility tests using fluconazole and voriconazole. We found that N. ramosa facilitated the highest rate of biodeterioration for onions and cucumber. Our anti-fungal tests revealed that non-aflatoxigenic A. tamarii was susceptible to voriconazole, but resistant to fluconazole. A. violaceofuscus (also non-aflatoxigenic) was found to be susceptible to both anti-fungals, while N. ramosa was resistant to both the anti-fungals tested. This study underscores the ability of fungi to degrade vegetables, and the need to focus on intervention through both chemical and best practices.