Revalorization of green tea waste through the production of cellulases by solid-state fermentation using a Aspergillus niger 28A.

Revalorization of green tea residues (GTR) was carried out through cellulase production by solid-state fermentation (SSF) using Aspergillus niger 28A. An exploratory study in the production of endocellulases (EC), β-glucosidases (BG), and total cellulase activity (FPUase) was carried out. The effect of operational conditions as moisture, temperature, and kinetic time was evaluated. The BG was partially purified by dialysis and ultracentrifugation, and the optimal pH and temperature for its activity were determined. It was found that A. niger 28A produced high titers of EC (65.85 ± 2.18 IU/g), FPUase (5.44 ± 0.11 FPU/g), and BG activities (1,016.52 ± 3.58 IU/g) in the exploratory analysis. The best operational conditions for enzymes production were 34 °C and 96 h for EC and FPUase activities, and 32 °C, 65% moisture, and 120 h for BG activity, respectively. After the partial purification process, the BG reached a specific activity of 496.90 ± 75.04 IU/mg. The optimal conditions for BG activity from the partially purified extracts were pH 4 and 60 °C. GTR constitutes a suitable biomass and substrate in the production of cellulase, reaching high titers of BG, proposing a way for its revalorization through the generation of high added value products as enzymes for the depolymerization of cellulose. [ABSTRACT FROM AUTHOR]