Antimycotic and Antibacterial Activity of Aframomum melegueta Seed Extracts Against Bacteria and Fungi Species from Food Sources

The antibacterial and antimycotic activity of Aframomum melegueta seeds were investigated against Escherichia coli, Staphylococcus aureus, Pseudomonas earuginosa, Salmonella species, Klebsiella species, Bacillus species, Fusarium species, Rhizopus species, Aspergillus species, Penicillium species and Mucor species isolated from spoiled bread and tomatoes using agar well diffusion method. The result showed that the ethanol extract exhibited higher antibacterial activity more than the aqueous extract with Bacillus sp. having the highest zone of inhibition (28mm, 23mm), followed by Salmonella sp. (26mm, 22mm), S. aureus (24mm, 19mm), Klesiella sp. (22mm, 17mm) and E. coli (20mm, 16mm) while P. earuginosa was the least (18mm, 15mm). The antifungal activity showed that Rhizopus sp. was the most inhibited by both ethanol and aqueous extracts respectively (20mm and 16mm), followed Penicillium sp. (17mm and 12mm), Aspergillus sp. (14mm and 11mm) and Fusarium sp. (14mm and 10mm) while Mucor sp. was the least (15mm and 9mm). The minimum inhibitory concentrations (MICs) of the aqueous seed extracts showed that MIC of E. coli, S. aureus, Salmonella sp. and Bacillus sp. was 20mg/mL. MIC for P. earuginosa, Klesiella sp. and Rhizopus sp. was 30mg/mL while Fusarium sp., Aspergillus sp., Penicillium sp. and Mucor sp. have MICs of 50mg/mL. The MICs of the ethanolic extract showed that E. coli and S. aureus have MICs of 10mg/mL, P. earuginosa, Klesiella sp., Penicillium sp. and Rhizopus sp. have 20mg/mL, Fusarium sp., Aspergillus sp. and Mucor sp. have 30mg/mL while Bacillus sp. was the most susceptible with MIC of 5mg/mL. The low MICs are indication of strong antibacterial and antimycotic effects of the extracts. Hence, the extracts could be used in treating infections associated with the test organisms and as well as serve as potential food preservative.