Evaluation of lipid biosynthesis ability by Rhodotorula spp

DÉBORA DANIELA MAZA; SILVANA C. VIÑARTA; LUCIA I. CASTELLANOS FIGUEROA; MANUEL J. AYBAR

Bariloche

Simposio; XXXIV International Specialized Symposium on Yeast; 2018

ISSYeast

NumerousRhodotorula spp. were characterized as oleaginous yeasts. Under certain cultureconditions, they can accumulate neutral lipids, mainly triglycerides (TAG), ina high proportion of dry biomass (20-70%). Microbial TAG can be used as rawmaterial for biodiesel synthesis and they are attractive for biofuels industry.The capability to synthesize lipids among 8 strains of Rhodotorula sppwas investigated and the most efficient strain was selected forbiotechnological purposes. R. toruloides (Y-6985, Y17092, Y 6987, Y1588and Y-1091), R. glutinis (Y-34 and R4) and R. mucilagionosa (RCL11)were cultured under nitrogen limiting conditions and excess of carbon source. Yarrowialypolitica (Y-323) was included as a positive control. Lipid accumulationwas evaluated comparatively in the nitrogen-limited glucose-based GMY medium.Yeasts were cultured at 25 °C for 120 h, with agitation (250 rpm). Lipid bodieswere observed by fluorescence microscopy with the lipophilic dye Nile red inall 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. Yeastsaccumulated between 19-38% (w / w) of lipids. R. glutinis R4 showed thehigher growth (17g/l) and lipid accumulation (38%). The composition of thefatty acids determined by GC-FID showed a profile similar to vegetable oils andsuitable for use as a raw material in the synthesis of biodiesel, with 61% ofoleic acid. These results indicate that the lipids produced by R. glutinis R4could be used as raw material for the synthesis of biodiesel and other biotechnologicalapplications. R. glutinis R4 accumulates significant amounts of lipidsand could be studied for commercial purposes because of its high potential forthe synthesis of lipids of industrial interest.