Volatile compounds secreted by the oyster mushroom (Pleurotus ostreatus) and their antibacterial activities

The oyster mushroom (Pleurotus ostreatus) is widely cultivated, but the volatile compounds it produces are little known. Several methods of isolation of Volatile components were compared: extraction by carbon tetrachloride, vacuum distillation, and conveyance by nitrogen flow. The observed order of extraction efficiency was CCl4 > vacuum 1 N-2. Compounds extracted by CCl4 were 3-octanone, 3-octanol, 1-octen-3-ol, benzaldehyde, l-octanol, benzoic acid, and an-unidentified trace component. The extracted mixture of compounds demonstrated strong antibacterial activity against some bacterial strains. Addition of a facsimile mixture containing these volatile compounds to a culture broth resulted in complete inhibition of the eight bacteria used for antibacterial assay. Benzaldehyde, which does not contribute notably to the inhibition of bacterial growth, is formed as a reaction to the stress of CCl4 contact or vacuum dehydration. The amount of benzaldehyde I produced may be an indicator of the degree of stress imposed.