BIOACTIVITY AND PHYTOCHEMICAL ANALYSIS OF THE MUSHROOM Rigidoporus lignosus (Klot) IMAZEKI

Abstract

The antagonistic effect of hot and cold water extracts of Rigidoporus lignosus was investigated in-vitro against some pathogenic microorganisms: Staphylococcus aureus , Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans. The extracts showed a wide spectrum of antimicrobial activity. The minimum inhibitory concentration (MIC) of the hot and cold water extracts against Staphylococcus aureus were 16g/150ml and 20g/150ml respectively. For Candida albicans, the MIC of the hot and cold water extracts were 16g/150ml and 14g/150ml respectively.The MIC of E. coli was 20g/150ml for both cold and hot water extracts.The extracts did not inhibit Pseudomonas aeruginosa and Klebsiella pneumoniae. The minimum bactericidal concentration (MBC) of cold water extract against Staphylococcus aureus was 20g/150ml. The hot water extract showed an MBC greater than 20g/150ml for this organism. The MBC of E coli for both hot and cold water extract was >20g/150ml.With cold water extract, the MBC for C. albicans was 16g/150ml but >20g/150ml using hot water extract.The lowest zone of inhibition against C. albicans was 6.00± 00mm at 6hours using 20g/150ml of either hot or cold water. This organism had the widest zone of inhibition of 12.67± 0.33mm at 24 hours using hot water. The next was E coli with a zone diameter of 12.36±0.09mm at 72hours using hot water extract. This was not significantly different (P=0.05) from that of S.aureus (12.33±0.33mm) at 24 hours using 16g/150ml. Phytochemical analysis of the extract showed it to contain flavonoids, saponins and alkaloids which are probably responsible for its biological activity. Both hot and cold water extracts of the mushroom Rigidoporus lignosus will be helpful in managing bacterial and fungal infections or employed as food preservative.