Solid-state bioprocessing of sugarcane bagasse with Auricularia fuscosuccinea for phenolic compounds extraction.
Coniglio, R., Diaz, G., Lopez, C., Restelli, M., Grassi, E., Alberto, E. and Zapata, P.
Universidad Nacional de Misiones, Facultad de Ciencias Exactas, Quimicas y Naturales, Instituto de Biotecnologia Misiones "Maria Ebe Reca" (INBIOMIS), Laboratorio de Biotecnologia Molecular, Misiones, Argentina.
CONICET, Buenos Aires, Argentina.
Instituto Misionero de Biodiversidad, Puerto Iguazu, Misiones, Argentina.
Laboratorio de Micologia y Cultivo de Hongos Comestibles y Medicinales. Instituto Tecnologico de Chascomus, Universidad Nacional de San Martin-CONICET. Chascomus, Buenos Aires, Argentina.
Sugarcane bagasse is a natural source of phenolic compounds. However, these compounds are bound to lignocellulose components, reducing their ability to function as good antioxidants. These linkages are hydrolyzed by enzymes like beta-glucosidases, increasing free phenolics. Auricularia is a food-grade genus capable of producing beta-glucosidases. The aim of this work was (I) to determine naturally occurring species of Auricularia and (II) to obtain phenolic compounds through the solid-state bioprocessing of sugarcane bagasse. We have successfully isolated five strains that were assigned to the taxon A. fuscosuccinea. We determined beta-glucosidase activity by fluorescence plate assay of the five isolated strains and adjusted an optimal temperature for mycelial growth at 30 degrees C. A. fuscosuccinea LBM 243 was chosen for solid-state bioprocessing of sugarcane bagasse. beta-glucosidase activity (12.2 +/- 0.62 U l(-1)) and protein content (51.58 +/- 6.26 mg l(-1)) were highest on day 20 of culture. The maximum value of total phenolic content (507.5 +/- 9.05 mg l(-1)) was obtained at day 20 and antioxidant capacity (34.44% +/- 11.20) was highest at day 10, both in ethanolic extracts. The best performance of ethanol against methanol extraction in this work is highlighted considering ethanol to be a safe, efficient, and low-cost solvent.
Preparative Biochemistry and Biotechnology 52(6): 701-710 (2022)