Characterization of the de-oiled yeast biomass for plausible value mapping in a biorefinery perspective

Oleaginous yeast fermentation process has gained attention for yeast single cell oil production. However, after lipid extraction, the leftover de-oiled yeast biomass has not been investigated in detail for its suitability for thermochemical conversion. To understand the structural and morphological changes, the comparative characterization of yeast and de-oiled yeast biomass before and post lipid extraction is necessary. The present study investigates the characteristics of an oleaginous yeast Rhodotorula mucilaginosa IIPL32's de-oiled biomass for its potential utilization. FTIR, XRD, SEM, EDX, XRF, and TGA analysis were performed to understand the biomass properties. Increased surface area and structural changes were observed in de-oiled yeast biomass with an increase in crystallinity, indicating chitosan availability. Maximum thermal degradation temperature was reduced to 260 °C for de-oiled yeast biomass from 300 °C for dried yeast after lipid extraction. The findings favored de-oiled yeast biomass for multiple applications that merit further detailed investigation with different thermochemical interventions.