High yield production of lipid and carotenoids in a newly isolated Rhodotorula mucilaginosa by adapting process optimization approach

Abstract

Rhodotorula sp. is a robust microbe, which can synthesize a wide range of products such as lipids and carotenoids. In the present study, we have attempted to enhance the production of lipids and carotenoids from a newly isolated Rhodotorula mucilaginosa using a process optimization approach. Among the carbon source screened, glucose showed enhanced lipid and carotenoid production of 46.19% (w/w) and 36.2 mg/g, respectively. The low C/N has influenced lipid production by 43.5% and the high C/N ratio favored carotenoid production (41.06 µg/g). The sodium acetate with 1.5% (w/v) concentration showed a lipid content of 48.28% and carotenoid of 41.16 mg/g. Further with the optimum levels of RPM (180), pH (6), and temperature (30 °C), the maximum lipid and carotenoid were found to be 51.89%, and 43.34 µg/g, respectively. In a batch bioreactor, MSM medium with sodium acetate showed a maximum lipid content of 54%. The lipid and carotenoid were successfully characterized by laser Raman spectroscopy, a label-free method and the FAME analysis clearly showed the high content of palmitic acid (C16:0) 21.05 (% w/w), oleic acid (C18:1) 56.18 (%w/w) and linoleic acid (C18:2) 12.25 (% w/w), which is suitable for biodiesel preparation.