CONICET | Buscador de Institutos y Recursos Humanos

Numerous Rhodotorula spp. were characterized as oleaginous yeasts. Under certain culture conditions, they can accumulate neutral lipids, mainly triglycerides (TAG), in a high proportion of dry biomass (20-70%). Microbial TAG can be used as raw material for biodiesel synthesis and they are attractive for biofuels industry. The capability to synthesize lipids among 8 strains of Rhodotorula spp was investigated and the most efficient strain was selected for biotechnological purposes. R. toruloides (Y-6985, Y-17092, Y-6987, Y-1588 and Y-1091), R. glutinis (Y-34 and R4) and R. mucilagionosa (RCL11) were cultured under nitrogen limiting conditions and excess of carbon source. Yarrowia lypolitica (Y-323) was included as a positive control. Lipid accumulation was evaluated comparatively in the nitrogen-limited glucose-based GMY medium. Yeasts were cultured at 25 °C for 120 h, with agitation (250 rpm). Lipid bodies were observed by fluorescence microscopy with the lipophilic dye Nile red in all strains but the number, size, and shape of lipid bodies as well as, intensity and persistence of fluorescence were different for each strain. Growth cell, production and accumulation of lipids were determined. Yeasts accumulated between 19-38% (w / w) of lipids. R. glutinis R4 showed the higher growth (17 g/l) and lipid accumulation (38%). The composition of the fatty acids determined by GC-FID showed a profile similar to vegetable oils and suitable for use as a raw material in the synthesis of biodiesel, with 61% of oleic acid. These results indicate that the lipids produced by R. glutinis R4 could be used as raw material for the synthesis of biodiesel and other biotechnological applications. R. glutinis R4 accumulates significant amounts of lipids and could be studied for commercial purposes because of its high potential for the synthesis of lipids of industrial interest.