ABSTRACT

Cashew nut is the most important product ofthe cashew tree and its oil contains high proportion ofunsaturated fatty acids and finds uses in medicine and cosmetics industries. This study aimed at evaluating the antibacterial activities of cashew nut oil against coliforms. The coliforms used in the study include E. coli and Klebsiella spp. The oil was extracted from the cashew nut by the solvent extraction method using the Soxhlet extractor. The antibacterial activity ofthe cashew nut oil was analyzed using the agar well diffusion method and inhibition zones were recorded and compared to that produced by a commercial antibiotic, Chloramphenicol. The cashew nut oil produced highest inhibition zone in E. coli at 100% concentration (16mm) and lowest at 20% concentration (10mm) while Klebsiella spp. produced the highest inhibition zone also at 100% concentration (18mm) and the lowest at 10% concentration (8mm). These were close to that produced by the organisms when tested against the commercial antibiotic (20mm and 19mm) for E. coli and Klebsiella spp. respectively. The MIC was recorded at 80% concentration for E. coli and 40% for Klebsiella spp. and MBC at 100% concentration for E. coli and 40% for Klebsiella spp. From this study, it is worth mentioning that the antibacterial activity ofthis oil is dependent on the concentration of the extract and also the method of extraction. Hence, it can be said that further studies on extracts ofA. occidentale should involve refining or purifying a and concentrating the active ingredient to determine its real effect on pathogenic microorganisms.