This work investigated the xylanase production by fungi isolates from tropical agroforestry systems using peach-palm industrial waste as a substrate. Trichoderma stromaticum AM7 was the best xylanase producer and there was a 160% increase in xylanase activity after optimizing by the Box–Behnken statistical design. The optimization process demonstrated that the maximum activity occurred at 0.95% nitrogen concentration after 6 days of cultivation at 32°C, which achieved a yield of 1440 U g⁻¹ of dry initial substrate. Analysis by scanning electron microscopy showed degradation of the fibers after cultivation. The optimum pH and temperature for xylanase activity were 5.0 and 50°C, respectively. The extensive degradation of the peach-palm waste and xylanase production by T. stromaticum AM7 was due to the combination of a good physicochemical composition of the culture medium and the characteristics of the selected fungus.

A sequential design strategy was applied to optimize the secretion of pectinases by a Saccharomyces cerevisiae strain, from Brazilian sugarcane liquor vat, on passion fruit residue flour (PFRF), through solid-state fermentation (SSF). A factorial design was performed to determine the influence variables and two rotational central composite designs were executed. The validated experimental result was of 7.1 U mL⁻¹ using 50% PFRF (w/w), pH 5, 30 °C for 24 h, under static SSF. Polygalacturonase, pectin methyl esterase, pectin–lyase and pectate–lyase activities were 3.5; 0.08; 3.1 and 0.8 U mL⁻¹, respectively. Shotgun proteomics analysis of the crude extract enabled the identification of two pectin–lyases, one pectate–lyase and a glucosidase. The crude enzymatic extract maintained at least 80% of its original activity at pH values and temperatures ranging from 2 to 8 and 30 to 80 °C, respectively, over 60 min incubation. Results revealed that PFRF might be a cost-effective and eco-friendly substrate to produce pectinases. Statistical optimization led to fermentation conditions wherein pectin active proteins predominated. To the extent of our knowledge, this is the first study reporting the synthesis of pectate lyase by S. cerevisiae.