The Mexican mezcal industry annually processes approximately 2.92 × 105 t of mezcal agave, generating roughly 1.46 × 105 t of agave leaves per year, which represents a potential carbon source of at least 8170 t via enzymatic processing of agave leaf juice. This carbon source is considered an attractive alternative to produce biofuels and/or chemical products since it is produced and used without adversely affecting the environment. The aim of this investigation was to determine the effect of temperature, pH, enzyme concentration, and bioreaction time on the enzymatic hydrolysis of agave leaf juice enriched in fructan to maximize the fermentable sugars production from three varieties of mezcal agave, using a low‐cost commercial brand of hydrolase. This process generated a sugar‐enriched juice of 80.07–136.12 g/L of reducing sugars. A Box‐Behnken experimental design and a mathematical surface response analysis of the hydrolysis were used for process optimization.

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The production of high‐activity β‐glucosidase at low cost is essential to increase the efficiency of cellulose hydrolysis, necessary for the economically feasible production of biofuels from the conversion of renewable lignocellulosic resources, specifically agricultural waste. In this work, the Aspergillus niger CDBB‐H‐175 strain was used for the production of extracellular β‐glucosidase. In the first stage of this work, the production of β‐glucosidase was carried out in a shake flask, using different carbon sources in order to evaluate the effect of the substrate on enzyme activity; in this way, it was determined that the best substrate is maltose, obtaining 2954 U/ml of β‐glucosidase activity at 31 days of culture. In the second stage, a laboratory‐scale study was done using two discontinuous bioreactor systems for submerged fermentation, stirred tank and airlift, using maltose, sucrose, and glucose as a carbon source. The results showed that β‐glucosidase with the highest enzymatic activity (3122 U/ml at 192 h of fermentation) was produced at uncontrolled pH conditions in an airlift bioreactor with maltose. In a third stage, using an airlift bioreactor with maltose, an orthogonal experimental design L4 with three factors was applied: pH, aeration, and maltose concentration. The aeration was of utmost importance to guarantee a better enzymatic expression, and acidification of the culture medium during the fermentation process was another necessary condition for a greater enzymatic production.

In this work, the effect of inlet-gas superficial velocity over the circulation liquid velocity, gas holdup and mass transfer, from an airlift bioreactor with settler were studied by Computational Fluid Dynamics (CFD) modeling and contrasted with experimental results. Multiphase mixture model and κ-ε turbulence model were used to describe the two phases gas-liquid flow pattern in airlift bioreactor. The hydrodynamic parameters such as liquid circulation velocity and gas holdup were computed by solving the governing equations of continuity, moment and turbulence transport using the finite volume method. Global mass transfer coefficient was evaluated through the Higbie’s penetration theory and the two-phase fluid dynamic theory. Comparison between our numerical data and experimental data previously reported in the literature was done. Numerical and experimental data were very close, and the differences found were discussed in terms of the limitations of this study.