Inhibitory Activity of the Lentinus edodes (Berk.) Pegler and Auricularia polytricha (Mont.) Sacc. Crude Extracts

Abstract

Increasing trend in resistance of microorganisms to commercially available antibiotics deems it necessary to find new sources of antimicrobial agents. Possible candidates are edible mushrooms such as Lentimts edodes (Berk.) Pegler and Auricularia polytricha (Mont.) Sacc. Aqueous, ethanol and hexane extractions were performed to obtain the extracts of the two mushrooms species. The fruiting bodies of the two mushroom species were dried, ground, boiled and filtered to prepare the aqueous extract. The dried and ground samples were soaked in ethanol and hexane and placed in the rotary evaporator for the ethanolic and hexanoic extracts; respectively. These extracts were investigated for inhibitory activity using the Kirby-Bauer Disk Diffusion method with Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 6538 as standard test organisms. Results showed that the aqueous extract of both mushrooms did not exhibit inhibitory activity against the test organisms. Staphylococcus aureus ATCC 6538 showed partial susceptibility on the ethanolic crude extract of A. polytricha and on the hexanoic crude extract of L. edodes. Escherichia coli ATCC 25922 did not show susceptibility in any of the crude extracts. In summary, the polar and non-polar solvents extracted probable antimicrobial metabolites which showed zones of inhibition against Staphylococcus aureus ATCC 6538 (hexanoic extract of L. edodes and ethanolic extract of A. polytricha). The zones of inhibitions were however still classified as resistant when compared to the NCCLS antimicrobial standard zones of sinhibitions.