The Antibacterial Activity of Coffea robusta Crude Leaf Extracts Using Different Solvents

Abstract

The leaves of Coffea robusta were observed for its antibacterial property. Water, ethanol and hexane extractions were done to extract the metabolites from the leaves. In water extraction, the leaves were ground, boiled and filtered. In ethanol and hexane extractions, the leaves were soaked in the solvents and were placed in the rotary evaporator. Using the Kirby-Bauer Disk Diffusion Method, the antibacterial property of the three different C. robusta leaf extracts was observed. The antibacterial property was tested against Bacillus cereus ATCC 10987, Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 6538. The results showed that C. robusta leaves extracts exhibit inhibitory effects on S. aureus. B. cereus showed susceptibility to water and ethanoic extracts. E. coli did not show susceptibility to any of the extracts. Several factors may affect the activity of the metabolites responsible for the antimicrobial effect such as quantity of compounds extracted from the leaves, the gram positivity or negativity of the bacteria used, age of the leaves used and the solvents used.