This study aimed to evaluate solid-state fermentation (SSF) as a sustainable approach for the simultaneous detoxification of olive pomace (OP) and the production of industrially relevant enzymes. OP, a semisolid byproduct of olive oil extraction, is rich in lignocellulose and phenolic compounds, which limit its direct reuse due to phytotoxicity. A native strain of Aspergillus sp., isolated from OP, was employed as the biological agent, while grape pomace (GP) was added as a co-substrate to enhance substrate structure. Fermentations were conducted at two scales, Petri dishes (20 g) and a fixed-bed bioreactor (FBR, 2 kg), under controlled conditions (25 °C, 7 days). Key parameters monitored included dry and wet weight loss, pH, color, phenolic content, and enzymatic activity. Significant reductions in color and polyphenol content were achieved, reaching 68% in Petri dishes and 88.1% in the FBR, respectively. In the FBR, simultaneous monitoring of dry and wet weight loss enabled the estimation of fungal biotransformation, revealing a hysteresis phenomenon not previously reported in SSF studies. Enzymes such as xylanase, endopolygalacturonase, cellulase, and tannase exhibited peak activities between 150 and 180 h, with maximum values of 424.6 U·g⁻¹, 153.6 U·g⁻¹, 67.43 U·g⁻¹, and 6.72 U·g⁻¹, respectively. The experimental data for weight loss, enzyme production, and phenolic reduction were accurately described by logistic and first-order models. These findings demonstrate the high metabolic efficiency of the fungal isolate under SSF conditions and support the feasibility of scaling up this process. The proposed strategy offers a low-cost and sustainable solution for OP valorization, aligning with circular economy principles by transforming agro-industrial residues into valuable bioproducts.

In the musts of wines there are spoilage yeasts that produce negative effects on the flavor. To try to eliminate it SO2 is used in wineries. However, this is toxic to human health and the World Health Organization (WHO) promotes an immediate reduction in its consumption. An alternative to the use of SO2 is the addition of killer yeast to eliminate or reduce the undesirable yeast. In previous works, was found that pH is a relevant variable in controlling the population of killer yeast and, for that reason, for the growth of undesirable yeast. It improves the fitness of the killer yeast and the inhibitor. In addition, it is a manipulable variable through the organic acids allowed in wines. Moreover, a new improvement to the mathematical model is proposed, incorporating the parametric variation with pH. Likewise, the new model was simulated using Matlab for the optimization by Monte Carlo method for the minimization of the spoilage yeasts population and the maximization of the growth of the killer. The optimum value for the objectives was pH 3.98. The results of the simulation were validated experimentally. The improved model is a need for the oenology industry, it allows the spoilage yeasts control.