Biotransformation of 1,8-cineole by solid-state fermentation of Eucalyptus waste from the essential oil industry using Pleurotus ostreatus and Favolus tenuiculus.

Biotechnological conversion of low-cost agro-industrial by-products, such as industrial waste or terpenes from the distillation of essential oils from plants into more valuable oxygenated derivatives, can be achieved by using microbial cells or enzymes. In Argentina, the essential oil industry produces several tons of waste each year that could be used as raw materials in the production of industrially relevant and value-added compounds. In this study, 1,8-cineole, one of the components remaining in the spent leaves of the Eucalyptus cinerea waste, was transformed by solid-state fermentation (SSF) using the two edible mushrooms Pleurotus ostreatus and Favolus tenuiculus. As a result, two new oxygenated derivatives of 1,8-cineole were identified: 1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-ol and 1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-one. Additionally, changes in the relative percentages of other aroma compounds present in the substrate were observed during SSF. Both fungal strains have the ability to produce aroma compounds with potential applications in the food and pharmaceutical industries.