The grape pomace and wheat bran is rich in bioactive compounds that may be conjugated to the plant cell wall, making it difficult to recover. The objective of this study was to produce an enzymatic complex concomitant to the release of phenolics from grape pomace and wheat bran, by solid-state fermentation (SSF), using the mutant strain Aspergillus niger 3T5B8. Both substrates showed potential for the production of hydrolytic enzymes, mainly for xylanase and β-glucosidase enzymes with grape pomace and wheat bran, respectively. In addition, SSF showed a more than 50% increase in the phenolic release of the substrates.