(625p) Recovery of phenolic acids from biologically treated corn silage by Trametes versicolor

Corn silage consists of stover (leaves, stalks, husks) and the ear (cob and grain). It is commonly used used as a cattle feed, but recently it has been more often used together with cattle manure in biofuel production in anaerobic co-digestion.

Extraction of bioactive phenolic compounds, among them phenolic acids, is the first step in their utilization from natural sources. Highly polymerized phenolic compounds are bonded in complexes with proteins, fibres and polysaharides. One of the possible ways to release that compounds is the application of environmentally friendly method such as biological pretreatment of the substrate.

The aim of this work was to investigate the influence of biological pretreatment of corn silage with white-rot fungus Trametes versicolor on the enhancement of phenolic acid (p-coumaric acid: p-CuA, ferulic acid: FA; p-hydroxybenzoic acid: p-HBA; caffeic acid: CA, syringic acid: SA, vanillic acid: VA) extraction efficiency as a consequence of lignocellulose degradation.

White-rot fungus T. versicolor was cultivated on corn silage in solid-state conditions (SSF) during twenty days. Phenolic compounds were extracted from corn silage before, during and after SSF by 50 % aqueous ethanol at 80 ^°C during two hours.

Initial concentrations of phenolic acids were 206.29 mg/g_db, 44.76 mg/g_db, 30.41 mg/g_db,15.05 mg/g_db, 9.68 mg/g_db and 2.82 mg/g_db for p-CuA, FA, CA, VA, p-HBA and SA, respectively. After biological pretreatment, 1.8-fold, 3-fold, 3.4-fold and 10.4-fold higher concentrations of four phenolic acids, CA, p-HBA, VA and SA were gained, respectively.

Key words: Corn silage, phenolic acids, Trametes versicolor

Acknowledgment: This work is done within ProBioTech project (RC. 2.2.08-0045) which is co-financed by the European Regional Development Fund (ERDF)