Abstract

The research was carried out to determine and to compare the antimicrobial activity of different concentrations of acetonic and ethanolic extracts of a macrofungus Boletus variipes on three bacterial isolates: Escherichia coli, Staphylococcus aureus, and Bacillus subtilis, and two fungi: Candida albicans and Aspergillus fumigatus in vitro. The acetonic extract showed relatively strong antimicrobial activity, inhibiting both bacterial and fungal growth in the range of 12.5mg/ml-100mg/ml. Maximum antimicrobial activity of the acetonic extract was found in E. coli with a minimum inhibitory concentration (MIC) of 12.5mg/ml. The measured MICs for Staphylococcus aureus, Bacillus subtilis and Candida albicans were 25mg/ml, 25mg/ml and 50mg/ml respectively while Aspergillus fumigatus was not inhibited. The ethanolic extract did not show any antimicrobial activity and this inactivity may be due to insolubility of the active compounds of the sample in ethanol or the presence of inhibitors to the antimicrobial components. The inactivity of the ethanolic extract may also be attributed to the very low volatility of ethanol which tends to extract less of the active ingredients or compounds from the macrofungus Boletus variipes sample unlike the high volatility acetone.