Tuesday, April 30, 2013
Exhibit Hall
The main feedstock for biodiesel is triacyl glycerides, which can be obtained by submerged fermentation of oleaginous yeast, known as single-cell oil (SCO). The residual sugar from sucrose crystallization and refining processes from sugarcane can be used as raw material for the production of SCO. This study aimed to evaluate the performance of oleaginous yeasts Rhodotorula glutinis CCT 2182, Rhodosporidium toruloides CCT 0783, Rhodotorula minuta CCT 1751 and Lipomyces starkeyi DSM 70296 to convert sugars from molasses in lipids. Pulsed-fed batch fermentations were performed in 1.65 L working volume bioreactors (pH 5.8, 28 °C and 40 % dissolved oxygen air saturation). The culture medium contained molasses supplemented or not with nitrogen. The glucose, fructose, sucrose, nitrogen, biomass and lipid concentration were measured. Measured maximum specific growth rate (µ), lipid productivity (Pr) and cellular lipid content (% w/w) were respectively 0.229 h-1, 0.398 g L-1h-1 and 42.0 % for R. toruloides; 0.221 h-1, 0.309 g L-1h-1 and 46 % for R. glutinis; 0.105 h-1, 0.105 g L-1h-1 and 27.0 % for R. minuta and 0.100 h-1, 0.165 g L-1h-1 and 46.0 % for L. starkeyi. Based on lipid productivity and microbial lipids content, it is possible to conclude that R. toruloides and R. glutinis present a high potential to produce alternative oil resource for biodiesel production.