Effect of different solvent extracted sample of Allium sativum (Linn) on bacteria and fungi

Abstract

This study was aimed to evaluate the antimicrobial activity of garlic-extracted samples against bacteria and fungi at different concentration, in various polar solvents. For this purpose, six different extracts were prepared, using five different polar solvents (methanol, ethyl acetate, petroleum ether, chloroforms and butanol) and water. Two different concentrations (1 and 2 mg disc^-1) of each extract were subjected for preliminary antibacterial screening against seven pathogenic bacteria by Kirby- Bauer disk diffusion method. The result of in vitro antibacterial screening showed that 6 extracts from garlic had different ranges of antibacterial activities. When garlic extracts were studied for their antibacterial potential against Gram-positive bacteria and Gram-negative bacteria, the butanol extracted samples showed the highest inhibitory effect against B. cereus (76% ZI at 2 mg disc^-1 concentration). Water extracted samples indicated a good range of inhibitory effect against Salmonella typhi (73% ZI at 2 mg disc-1) and butanol extracted sample showed highest activity against Erwinia carotovora (75% ZI). The data also showed that of petroleum ether, methanol and water did not show any  inhibitory effect against the tested microbes.

Key words: Solvent, bacteria, fungi, Allium sativum.