Onion is associated with micro-organisms which are capable of causing spoilage.

Onion is associated with micro-organisms which are capable of causing spoilage. Onions with rots were examined microscopically. A solution of it was made and the serial dilution of 1:10-1¬¬¬¬¬¬¬¬¬¬¬¬¬¬¬ to 1:1-5 were made from 10ml of the onions sample. From the dilution, 1ml of each diluent was plated on nutrient and saboor and dextrose agree to permit the grouth of the common bacterial and fungi, from the roffen onions. Duplicate plates were performed for each dilution. The plates was sivirled of gently to ensure even distribution of diluent and was incubated in inverted position of 370 c for 24 hours. After 24 hours, the colorues were counted, with vales yielding 30 to300 (to avoid TFTR and TNTC), the viable count per ml was defermined by multiplying the average number of colories of the duplicate plates by the corresponding factor (MPN table). Gram staining was carried out on the colories and examined microscopically. Representative colories were seperately sus-cultored on nutrient agar slopes for confirmatory characterization of the organism present Biochemical test for identification was also carried out. The result showed a mixed flora of bacterial and fungi including moulds as the organism responsible for spoilage of onions. The fungi isolated were Mucor spp rhizopus spp, Aspergilus spp and saccharomycis spp. The bacteria isolated from the sample were staphylococcus aureus, streptococcus pyogenes and Bacillus spp.