Valorization of Oilseed Agro-Industrial Coproducts Through Optimized Lipase Production by Trichoderma sp. in Submerged Fermentation

Abstract

This study integrates microbial biotechnology, bioprocess optimization, and circular bioeconomy principles to valorize oilseed agro-industrial coproducts as low-cost inducing substrates for lipase production. Palm kernel cake (PKC), canola cake, andiroba cake, and brewer’s spent grain were evaluated as carbon sources for extracellular lipase production by the wild-type strain Trichoderma sp. LEPM-711 under submerged fermentation. Qualitative screening in olive oil/rhodamine B medium confirmed the strain’s lipolytic potential. Among the substrates tested, PKC showed the strongest induction, reaching 4.68 U mL−1, and was therefore selected for nitrogen supplementation and statistical optimization. Peptone supplementation increased lipolytic activity to 8.41 U mL−1 after 72 h. A Plackett–Burman design identified CaCl2·2H2O, CoCl2·6H2O, and peptone as significant medium components, while response surface methodology established the optimal operational conditions as pH 6.0, 106 spores mL−1, and 2% (w/v) PKC. Under these conditions, the crude enzymatic extract reached 18.31 U mL−1 at pH 7.0 and 45 °C, corresponding to an approximately 3.9-fold increase over the initial PKC fermentation. These findings support the use of Trichoderma sp. LEPM-711 and oilseed coproducts as a sustainable platform for enzyme production and residue upgrading within applied natural sciences.