Phanerochaete Chrysosporium supported biovalorisation of grape pomace for hyper reducible sugar extraction

Abstract

In the Western Cape, South Africa and other regions globally, grape pomace (GP) is one of the abundant agro-waste from the winery industry. This study reports on the hyper-extraction of fermentable sugars from GP treated with white rot fungi (WRF) Phanerochaete chrysosporium BKMF 1767 to facilitate improved biovalorisation for total reducing sugars (TRS) extraction. TRS were quantified using the 3,5-dinitrosalicylic acid (DNS) reagent method. The free readily dissolvable sugars from the GP recorded for the bio-treated (BT) samples was 206.39 ± 0.06 mg/L and for the untreated (UT) samples was 271.05 ± 0.02 mg/L. Overall, the TRS yield for the Bio-treated (BT) and untreated (UT) samples was recorded as 205.68 ± 0.09 and 380.93 ± 0.14 mg/L, respectively, using hot water pretreatment (HWP) with 2266.00 ± 0.73 (BT) and 2850.68 ± 0.31 mg/L (UT), respectively, for dilute acid pretreatment (DAP); with 2068.49 ± 6.02 (BT) and 2969.61 ± 8.054 mg/L (UT) respectively, using the cellulase pretreatment (CP) method. Using the HWP as a reference, the relative increases imparted by the bio-treatment was higher (51%) for DAP and low (33%) for CP.