Studies on Antimicrobial Potentials of three Ganoderma species

The fruit bodies of three Ganoderma species namely G. lucidium, G. applanatum and G. australe were collected from the decaying logs within the University of Ibadan Botanical Gardens .Invitro antagonistic effect of the ethanol, methanol and distilled water extracts of these macro fungi were tested against some disease causing microorganisms. Both crude and pure extracts of these Ganoderma species exhibited various degree of inhibition against the test organisms. The widest inhibitory zone (20.3mm) were obtained with the crude methanolic extract of G. lucidium against Proteus mirabilis while the highest in-vitro antifungal activity (24.3mm) was observed in the crude ethanolic extracts of G. lucidium against Aspergillus niger. The lowest zone of inhibition (2.3mm) was demonstrated with the aqueous extract of G. australe against Escherichia coli and 2.7mm with purified extract of G. australe against Penicillum oxalium . The minimum inhibitory concentration (MIC) for the ethanol extract ranged between 1.7 and 5.0mg/ml for bacteria and between 2.0 and 6.0mg/ml for fungi. The implications of these findings were discussed. Key Word: Ganodermaspecies,Antimicrobial potentials,microorganisms, extraction, Botanical Gardens