Isolation and Molecular Characterization of Aspergillus Fu Migatus Variants from some Agricultural Products Obtained from Different Locations

Abstract

Post-harvest fungal and bacterial contamination significantly contributes to global food insecurity, particularly in regions like Ghana, where inadequate storage practices and environmental condi tions exacerbate losses. This study focused on the isolation and molecular characterization of As pergillus fumigatus variants from selected agricultural products, including fruits (oranges, man goes, and tomatoes) obtained from Accra markets and cocoa beans from Breman Asikuma, with additional assessments of their pathogenicity and possible control strategies. Total fungal popula tions varied by fruit type and the market from which they were obtained. For instance, fruit juices (orange, mango and tomato) recorded log₁₀ 3.0–3.4 CFU/g, and orange juice showed the least con tamination at log₁₀ 3.08 CFU/g). Fruit peels on the other hand, recorded lower contamination (log₁₀ 1.0–1.4 CFU/g), highlighting the pericarp's protective role. The aeromycoflora populations also varied. For example, Mallam Atta Market showed marginally higher airborne fungal loads (log₁₀ 1.43 CFU/g) compared to Madina Market. The prevalence of Aspergillus fumigatus in the various markets and on the different substrates sampled varied significantly (P ≤ 0.05). The percentage incidence of A. fumigatus for Mallam Atta Market was 12.4% in airspora and was isolated from all fruit samples. Madina Market: 7.3% in airspora but absent in mango juice. Cocoa bean shells registered 6% A. fumigatus contamination, posing potential mycotoxicosis and causing det rimental health implications to consumers. The A. fumigatus complex isolated in this study had morphological and microstructural differences in hyphal shape, conidia, conidiophore, phialide and vesicle sizes. Conidia were deciduous, globose, oblong and ellipsoidal with dark-green suede like colour with dense felt mycelial mass. Analysis of variance of morphological variability indi cated significant differences (p ≤ 0.05) in hyphal structures, conidia shapes (globose, ellipsoidal), and vesicle sizes among isolates, suggesting intra-species variants.