Production and recovery of cellulases through solid-state fermentation of selected lignocellulosic wastes

Abstract

Orange peel, apple pomace and rice fibre from vegetal beverage manufacturing were assessed for the production of cellulases though solid state fermentation (SSF). No increment in cellulases activity was observed during SSF, being the maximum activity that of the raw waste 8 ± 1, 7.8 ± 0.1 and 2.1 ± 0.2 International units (IU) g−1 Dry Matter for apple pomace, orange peel and rice fibre, respectively. In view of the results, the influence of the main cellulases extraction parameters in the activity recovery from raw waste was assessed. Results show a maximum activity recovery of 105 ± 27% for apple pomace in an extraction ratio 1:2 (w:v) using distilled water as extracting agent. 97 ± 13% and 139 ± 11% activity recovery for orange peel and rice fibre, respectively, were achieved at 1:3 (w:v) extraction ratio and distilled water with no agitation. Finally, zero waste strategies (aerobic stabilization and anaerobic digestion) were successfully applied to valorise the remaining waste after extraction.