Comparison of Antibacterial Activities of Fermented with those of Unfermented Annona muricata (L) Fruit Extracts

Abstract

Fermentation is known to enhance antibacterial activities of some plant products. The research aimed to compare the antibacterial activities of the fermented with those of unfermented fruits of Annona muricata, obtained from eastern Uganda. Ripe fruits were blended wholly and fermented for a period of one week, immediately after; fresh ripe fruits were blended in the same way. Cold maceration for extraction were used on the fermented and unfermented blends to obtain hexane, ethyl acetate and methanol extracts, which were tested against standard strains of Escherichia Coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus(ATCC 25923)and Streptococcus pyogenes (ATCC 19615), using modified agar diffusion technique. The micro-dilution method was applied for the determination of the minimal inhibitory concentrations (MICs). With the exception of hexane extracts, all the other extracts inhibited the growth of all the bacteria, but the corresponding fermented extracts inhibited greater. The study showed both the fermented and unfermented fruits of Annona muricata have antibacterial activity against both gram negative and gram positive bacteria, but the potency is higher with the fermented fruits.