Recycling Pollutants and Used Oils as Substrates for Producing Useful Lipids in the form of Single-Cell Oil by the Aerobic Yeast Yarrowia lipolytica

Nowadays, the non-conventional yeast Yarrowia lipolytica has become more useful in the field of biotechnology and its environmental applications, since it contains an excellent enzyme system that enables it to degrade and assimilate a wide range of substrates. Therefore, single-cell oil production that can potentially be used as a supplier of functional oils and/or biodiesel could be coupled with the use of hydrophobic waste, as a low-cost culture medium. In the current study, we were interested to investigate the potential of yeast Y.lipolytica L2 KF156787 with different carbon substrates, especially, to study its ability to degrade oils waste and single-cell oil production. The strain showed a high ability to grow on different carbon substrates, accumulate lipids, and efficiently decolorize the black dye (about 90%) in the presence of olive-mill waste, suggesting its feasibility and suitability for bioremediation of hydrophobic wastes with the simultaneous production of lipid-rich biomass. The profiles of fatty acids were not strictly dependent on carbon substrates but also on the strain, which it showed a clear biomodification effect on the substrates lipids used to a higher degree. Most of the fatty acids of the microbial lipid were unsaturated and corresponded mainly to oleic, and linoleic acids, making Y. lipolytica L2 KF156787 valuable from a nutritional point of view. Consequently, strain can be considered as a good tool for integration into bioremediation solutions that realize the requisites of the circular economy and of environmental sustainability. Graphical abstract