Isolation and Characterization of Bacteria and Fungi Associated with Tomatoes Spoilage in Farin-Gada Market, Jos.

This research was carried out to determine the bacteria and fungi associated with tomato spoilage. Tomatoes are vulnerable to bacteria and fungi attack, causing spotting, rotting cankers, pitting, and discoloration. These have contributed to its poor shelf life, high perishability, and huge losses during postharvest, as observed in large heaps of rotten tomatoes in refuse dumps in local and urban markets. A total of 15 deteriorated tomatoes were collected aseptically from 3 different sellers at Farin-Gada Market, Jos. Isolation and characterization of bacteria and fungi were carried out using standard cultural techniques. Nutrient agar, eosine methylene blue agar, and sabourad dextrose agar were the growth media used for the isolation of bacteria and fungi. The bacteria identified include Pseudomonas sp., Proteus sp., E. coli, Staphylococcus sp., Micrococcus sp., and Klebsiella sp., while fungi were identified based on their colony morphology and microscopic characteristics and include Rhizopus sp., Fusarium sp., Aspergillus sp., and Geotrichum candidum. E. coli was predominantly isolated among the bacteria isolates, with a percentage occurrence of 26.78%, while Staphylococcus sp. occurred the least (7.14%). Rhizopus sp. (31%) had the highest occurrence among the fungi isolates, with Fusarium sp. having the lowest occurrence at 18%. Statistically, there was no significant difference (p > 0.05) in bacteria and fungi between locations in the market. E. coli being present shows that the source of water probably used in the irrigation of tomatoes was faecally contaminated. Also, Aspergillus sp. and Fusarium sp. suggest food poisoning, all of which calls for public health concern when consuming even healthy tomatoes from the market. Good agricultural practices and proper handling become inevitable to eliminate faecal contamination and reduce spoilage agents.