Development of high biomass and lipid yielding medium for newly isolated Rhodotorula mucilaginosa

Abstract

Conversion of plant-based biomass into biofuels has been singled out as a way to achieve economically viable production chains. Over past few decades development in yeast oil production have been witnessed, which includes isolation of high lipid accumulating strains, understanding the metabolic pathways for oil production, genetic engineering strategies for overproduction of lipids and optimization of cultivation processes for converting lignocellulose biomass to oil. In the present investigation, screening, isolation and characterization of novel oleaginous yeast from oil refinery was carried out. The strain was identified as Rhodotorula mucilaginosa by 26s rRNA sequencing (Accession Number: KX533469). Glucose and peptone were identified as best carbon and nitrogen source for high biomass induction. Further, two-stage optimization using taguchi orthogonal array method and multi objective optimization using genetic algorithm was applied for the development of an optimized medium. Malt extract was found to be a key influencing factor in both biomass and lipid induction with high S/N ratio, followed by peptone and glucose. Batch bioreactor studies revealed that the lipid productivity follows mixed growth associated pattern with the higher lipid accumulation of 0.25 g/g biomass.