Biodiesel-mediated biodiesel production: A recombinant Fusarium heterosporum lipase-catalyzed transesterification of crude plant oils

Production of biodiesel from unrefined plant-derived oils has been considerably investigated but, to date, there appears to be a limit by phospholine gums and other contaminants in its conversion to biodiesel. The presence of such contaminants increases the melting point of the oils, thereby, making it unfavorable for lipase-catalyzed reactions at mild temperatures. Here, to circumvent this limiting effect, we explore the potential of biodiesel as a replacement for conventional organic solvents in solubilizing gum-formation contaminants in crude palm oil (CPO). A strategy of 1:1 CPO/biodiesel molar amount consolidates degumming and trans/esterification into one-step using immobilized Aspergillus oryzae expressing Fusarium heterosporum lipase. The innocuous biodiesel solvent not only ensured a 98.8 wt% biodiesel yield but also improved the catalytic activity of the whole-cell lipase. This allowed repeated use of the recombinant lipase in nine consecutive batches. At room temperature, biodiesel as a solvent saves on post-separation and reduces environmental footprints of the biodiesel production process.