Selection and Optimization for Lipid Production of a Newly Isolated Oleaginous Yeast, Rhodosporidium toruloides DMKU3-TK16

Abstract

Rhodosporidium toruloides DMKU3-TK16, an oleaginous yeast, was isolated from soil by an enrichment technique in nitrogen-limited medium I. Lipid production by this strain was highest in shaking flask cultivation at 150 rpm and 28°C in nitrogen-limited medium II containing per liter 70 g glucose, 0.75 g yeast extract, 0.55 g (NH₄)₂SO₄, 0.4 g KH₂PO₄, 2.0 g MgSO₄•7H₂O, with a pH of 5.5. Under these optimal conditions, when the C/N ratio of the medium was 140, R. toruloides DMKU3-TK16 produced a lipid quantity of 9.26 g/L, which was 71.30 % of the dry biomass (13.33 g/L) after 168 h of
cultivation. The major fatty acids of the cellular lipid were oleic acid (41.54%), palmitic acid (22.49%), linoleic acid (15.12%) and steric acid (14.56%).