Optimization of Lipase Synthesis by Native Fungal Strains via Solid-State Fermentation of Shea Nut Cake

Lipases are commercially valuable enzymes, recognized for their broad versatility and substrate specificity. Solid-state fermentation (SSF) offers a cost-effective and environmentally sustainable strategy for enzyme production, leveraging locally sourced agro-industrial residues. This study aims to identify and screen indigenous fungal strains with high lipase-producing potential and to evaluate shea nut cake as an alternative substrate for lipase production. A full factorial 323^2 experimental design was employed to systematically optimize SSF process parameters, including temperature (30°C, 35°C, 40°C), incubation time (72 h, 96 h, 120 h), and nutrient supplementation (glucose and yeast extract) as potential inducers or inhibitors. The objective of this optimization was to enhance lipase yield while minimizing production costs and environmental impact. Fungal isolates exhibited variable lipase production under different conditions. Aspergillus niger (C1) demonstrated the highest lipase yield (9.22 U/gds) at 40°C, 96 hours, with yeast extract supplementation, while Saccharomyces sp. achieved a maximum yield of 7.88 U/gds at 30°C, 120 hours, with glucose supplementation. Using indigenous fungal strains for lipase production through SSF of shea nut cake promotes sustainable agricultural practices, reduces agro-industrial waste, and offers economic benefits.