Utilization of multiple lipid sources in the production of biodiesel by using lipase nanoparticles from Candida rugosa in a nonaqueous system

Abstract

One of the major challenges for the sustainable fatty acid methyl or ethyl ester (FAME/EE, a.k.a biodiesel) production is the smart utilization of low‐cost feedstocks, e.g., waste cooking oil (WCO), brown grease, or algal lipids. Although traditional catalyst systems could be used to transform such feedstocks into biodiesel, some well‐established drawbacks are associated with their use. Alternatively, lipases can convert the FFA‐rich feedstocks into FAME/EE in a manner with less environmental impact. However, low enzyme activity in organic solvents and high cost remain challenging for the industrial application of lipase nanoparticles. In this study, we are addressing these drawbacks of lipase by developing lipase nanoparticles (LNP), cross‐linked lipase nanoparticles (CLNP), and immobilized LNP on iron oxide nanoparticles (IONP). Lipase from Candida rugosa was selected as an economic widely available source and purified to ca. >90%. Different formulations of nanoparticles were formed, and detailed surface and morphological characterizations were performed by using the various microscopy techniques, e.g., scanning and transmission electron microscopy, and atomic force microscopy, dynamic‐light‐scattering, and magnetic properties by the vibrating‐sample magnetometer. For structural characterization, Fourier‐transform infrared spectroscopy and X‐ray diffraction were used. Identification of fatty acid esters was done by gas chromatography coupled to a mass spectrometer. The activity of the LNP, CLNP, and LNP‐IONP formulations increased 10‐, 20‐, and 32‐fold in n‐hexane, 18‐, 42‐, and 54‐fold in 1,4 dioxane, and 13‐, 29‐, and 43‐fold in THF, respectively, compared to free lipase. Detailed analysis of fatty acid ester formation was performed using the different combinations of substrates (WCO and brown grease, methanol and ethanol), lipase formulations (free lipase, LNP, CLNP, and LNP‐IONP), and solvent systems (hexane, 1,4 dioxane, THF, and t‐butanol). The nanoparticulate lipase formulations converted a high percentage of fatty acid esters into biodiesel in less time and the overall operational stability of the system improved considerably.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.