The potential of magnesium oxide nanoparticles (MgONPs) in the transesterification of lipids produced by Rhodotorula minuta.

The urgent need to address energy security risks and global warming has led to exploration of renewable energy sources. One such avenue is biodiesel specifically focusing on the potential of Rhodotorula minuta, a type of yeast known for producing lipids that can be used as a sustainable alternative for production of biodiesel. In the current study, this promising yeast was evaluated for its potential to produce lipids. The morphological characterization was carried out by scanning electron microscope (SEM), and intracellular detail was studied by transmission electron microscope (TEM). Changes in content and cellular biomass were monitored at time intervals with the highest biomass yield of 12.4 g/l and lipid content of 6.2 g/l achieved after 72 h. In the present work, magnesium oxide nanoparticles (MgO NPs) were synthesized and extensively characterized through Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), SEM, TEM, and X-ray diffraction (XRD). By employing response surface methodology (RSM) with Box-Behnken design (BBD), optimal process conditions for transesterification could be determined. The best result achieved was a yield of 88.6% when the conditions were optimized, using methanol to oil ratio of 18:1 and 8% (w/w) amount of catalyst maintaining a reaction temperature of 55 °C and allowing the reaction to proceed for 120 min.