Microbial Agents of Tomato Spoilage in Onitsha Metropolis

Microbial agents of tomato spoilage in Onitsha metropolis, Nigeria were investigated. A total of 80 tomatoes were sampled, out of which 40 were fresh healthy intact tomatoes and the other 40 were spoilt tomatoes sold in 4 local markets within the zone. They were cultured on blood agar, MacConkey agar, tomato juice agar and Sabourand dextrose agar. No organism was isolated from fresh healthy intact tomatoes, but in spoilt tomatoes 6 species of fungi and 4 species of bacteria were isolated and identified, these include Candida tropicalis, penicilliumnotatum, Aspergillusniger, Fusariumoxysporum, Absidiacorynbifera, Rhizopusstonolifer, Escherichia coli, Klebsiella spp., Salmonella spp. and Pseudomonas aeruginosa. However, no protozoon was isolated. Thus, it was found out that both fungi and bacteria were responsible for tomato spoilage. In the fungal isolates, Candida tropicalis had the highest rate of occurrence 40 (34.5%), followed by Aspergillusniger 37(31.9%), Penicilliumnotatum 20(17.2%), Fusariumoxysporum 15(12.9%), Absidiacorynbifera 3(26%) and Rhizopusstolonifer 1(0.9%). In the bacterial isolates, Escherichia coli 31(54.5%) had the highest rate of occurrence followed by Pseudomonas aeruginosa 15(26.9%) while Salmonella spp. and Klebsiella spp. recorded 5 (8.9%) each. Thus, it can be related that the intake of spoilt tomatoes could be dangerous, since these organisms produce spores and toxins that could cause severe food poisoning that will result in fatal outcome.