Isolation and identification of fungi in onion bulbs obtained from markets in Awka metropolis, Anambra state, Nigeria

Abstract

Onion is one of the most important spice crops cultivated for its nutritious content for consumption and economic value globally. The study was carried out to investigate the fungi microbes associated with spoilage of onion bulbs around Awka metropolis. Onion bulbs with visible signs of spoilage were collected from four different markets in Awka namely; Eke Awka, Amaenyi, first and second markets Ifite and were cultured for the presence of fungi. A total of twenty (20) onion samples, five (5) from each study site were used. Samples were examined using various culture media, and Germ tube test. Data was analyzed using one-way ANOVA and chi-square test. The fungal organisms isolated were Saccharomyces spp, Fusarium spp, Rhizopus spp, Mucor spp, Aspergillus niger and Candida tropicalis. The fungus, Aspergillus niger had the highest percentage distribution of 30% while Candida tropicalis and Mucor spp had the least percentage of 10% each. The mean total colony count for fungi was highest in second market Ifite (66.80 ± 5.16) but lowest in Amaenyi market (45.60 ± 6.73). Some of the isolated fungi in this study have serious public health importance while others fasten spoilage of the onion bulbs. It is recommended that both farmers, marketers and consumers should take precautionary measures in preventing contamination and consumption of fungi contaminated onion.