ISOLATION AND IDENTIFICATION OF MICROORGANISMS ASSOCIATED WITH ONION SPOILAGE

The study was conducted to investigate the microorganisms associated with spoilage of onion bulbs around Afia Nine in Enugu metropolis . A total 10 samples were collected from Afia Nine market. Gram staining and Biochemical tests were used to characterize bacteria isolates. The technigues use in this study was pour plating technigues with nutrient, macConkey, CLED and Sabouraund dextrose agar. The bacteria species isolated were Staphylococcus spp, Bacillus spp, Pseudomonas spp, and Escherichia coli, while the fungi were Aspergillus spp and Mucor. Bacillus spp had the highest frequency of occurrence (52%) and the lowest was Pseudomonas spp 12%, whereas Aspergillus spp had the highest frequency of occurrence and the lowest was Mucor. The result of this research shows that spoilt onion bulb is a reservoir of both fungal and bacterial microorganisms which have been known to cause spoilage .Contamination could be due to exposure of the onion to poor environmental conditions such as humidity and temperature. Therefore dry conditions should be maintained during harvesting and onion bulbs should be handled gently to avoid bruises . Good storage facility of the onion bulbs should be provided, consumption of raw onion without prior heat treatment should be discouraged.