Antimicrobial properties of some Nigerian edible mushrooms

Abstract

In recent years, scientists have become more aware of the problems associated with drug resistance. This investigation was carried out to determine the proximate analysis and antimicrobial properties of three species of Pleurotus sajor caju, Pleurotus ostreatus and Pleurotus florida. Phytochemical compounds of the mushrooms were extracted using either ethyl acetate or distilled water as solvent, and the extracts were tested against 9 clinical isolates. The result of the proximate analysis showed that ash content ranged from 2.1 to 2.3, moisture (8.1-9.3%), dry matter (90.7 - 91.9%), crude protein (27.5 - 29.0%), fat (0.30 - 0.92%), crude fiber (17.3 – 19.2%), and carbohydrate (30.88 – 42.66 %). Qualitative phytochemical screening indicated that different Pleurotus species have various type of bioactive compounds, and antimicrobial activity study revealed that Candida albicans was inhibited by ethyl acetate extract (20.0 mm). Highest in-vitro antibacterial activity (23.0 mm) was exhibited by P. florida (ethyl acetate extract) against Enterobacter aerogenes. This was followed by the same extract against Staphylococcus aureus (22.0 mm) and P. ostreatus (ethyl acetate extract) against Klebsiella oxytoca (22.0). A significant zone of inhibition was observed in ethyl acetate extract of P. florida against all the test organisms except Escherichia coli. In conclusion, different mushrooms produced specific phytochemical compounds, and ethyl acetate extracts were more effective than aqueous extracts. Finally, further studies are needed to underpin and test these extracts against some other human pathogenic microbes coupled with purification and characterization of the bioactive compounds.