Preliminary Identification of Bacterial Species Contaminating Okra Fruits in Some Selected Markets in Owo, Nigeria

Abstract

In spite of Okra (Abelmoschus esculentus L.) cultivation relevance in the society, management of its post-harvest disease has stand out as major issue to plant pathologists. This study therefore reports findings on the spoilage bacteria associated with Okra fruit during post-harvest storage. Okra sample was purchased from three (3) local markets (Ogwagbe market, Areghona market and Oba market) in Owo local government and taken to the Plant Pathology Laboratory of the Department of Crops Soil and Pest Management, Federal University of Technology, Akure. About 2g of deteriorated Okra fruit sample was sterilized and aseptically transfer into the sterile 20cm2 beaker. The bacteria isolated were incubated at 37+ 20c for 24hours in a Nutrient Agar (NA) plate. At the end of incubation period the Colonies forming units from violet bacteria cells were counted and recorded appropriately per gram of each of the deteriorating Okra sample. Pure culture of individual isolates was kept at 40c for biochemical test and isolates were identified. A total of 26 bacteria were isolated and identified from the Okra sample from the 3 local markets on the basis of colony morphology and the staining characteristics. Location A has the highest population of bacteria isolate while location B and C had lowest bacterial population. The highest occurring genera can be found in Micrococcus, Bacillus and Staphylococcus followed by Alcaligenes, Pediococcus, and Erwinia. Alcaligenes odorans and Bacillus pumilus are the most occurring species of bacteria isolated from the market. Total viable counts ranges from 1.20 X 10-8 (cfu/g) to 1.72 X 10-8 (cfu/g). The highest average coliform forming unit occurs in Location A (1.52 X 10-8 (cfu/g)) while the least average coliform forming unit occurred in Location B (1.23 X 10-8 (cfu/g)). Alcaligenes odorans Bacillus pumilus and Micrococcus spp. had the highest frequency of occurrence (67 %). The presence of these bacteria on Okra fruit are potential threat to its production most importantly coliforms, pose a serious threat to consumers' health as the bacteria could produce toxins, which are poisonous when consumed. Proper handling methods should be adopted by both farmer and consumers to minimize the bacterial deterioration of okra fruit in the study area.