Deacidification of Jatropha curcas L acidic oil by recombinant CALB and Carica papaya esterase liquid preparations

Jatropha curcas L. is a promising nonedible feedstock for biodiesel production; however, its high free fatty acid (FFA) content hinders conventional alkaline transesterification by promoting soap formation and catalyst consumption. This study investigated enzymatic esterification as a pre-treatment strategy using liquid biocatalysts: a recombinant papaya esterase (CpEST) expressed in Komagataella phaffii, and a heterologously expressed Candida antarctica lipase B (CALB) in Yarrowia lipolytica, and a commercial liquid lipase (Eversa Transform, engineered lipase from Thermomyces lanuginosus), that were compared under identical reaction conditions. CpEST exhibited the highest deacidification efficiency, reducing oil acidity from 12.50 mg KOH/g to 0.28 mg KOH/g (1.1%) after 48 h at 30 °C. These results confirm the effectiveness of enzymatic catalysis in pre-treatment for biodiesel production. These findings highlight the potential of using liquid biocatalysts to improve biodiesel production efficiency, with future perspectives favouring liquid enzyme formulations as bioprocess development advances.