Single Cell Oil from Oleaginous Yeast Grown on Sugarcane Bagasse-Derived Xylose: An Approach toward Novel Biolubricant for Low Friction and Wear

Yeast lipid as single cell oil (SCO) is evaluated as an alternative renewable source of vegetable oils for a biolubricant formulation. The Rhodotorula mucilaginosa IIPL32 yeast strain is cultivated on lignocellulosic pentosans derived from sugarcane bagasse to produce the SCO. The chemical composition and distribution of variable fatty acids in the yeast SCO are characterized by NMR, FTIR, and GC × GC analyses. The high viscosity index and a low pour point of yeast SCO owing to the favorable composition of saturated and unsaturated fatty acids promise its potential as a renewable and environmentally friendly lube base oil. The yeast SCO as lube base oil significantly reduced the coefficient of friction (72%) and wear (24%) compared to those of conventional mineral lube base oil (SN 150). The fatty acids in the yeast SCO formed a good quality tribo-chemical thin film on the engineering surfaces, which not only reduced the friction but also protected the contact interfaces against wear. This study demonstrates that yeast SCO being renewable, biodegradable, and nontoxic, provides favorable physicochemical and tribophysical properties for good quality lubricant formulation and it can be a good alternative to the conventional mineral lube oil-based lubricants.