Taguchi design for optimization the microbial oil production from red oleaginous yeasts

An intracellular product from oleaginous yeasts  is increasing recognition of  the potential alternative fuel as  biodiesel via the triacylglycerol conversion through transesterification process. Taguchi design was used to study the highest lipid production from three red basidiomycete oleaginous yeast strains, Rhodosporidium toruloides TISTR 5123, 5154 and 5149 by optimizing carbon to nitrogen ratio, shaking speed and fermentation time in order to select the appropriate strain for industrial waste utilization. Two industrial wastes as crude glycerol and molasses were compared of lipid and biomass production with the standard glucose source under the same experimental design. The fatty acid profiles of these yeast were investigated by the comparison with the 37-component fatty acid as the reference standard by GCMS analysis. Results revealed that R. toruloides TISTR 5123 was found to accumulate the highest lipid yield of 38% under the C:N ratio of 60 at 200 rpm over the 60 hours fermentation time. The fatty acid profile of the major quantity of 41% of C18:0, 22% of C16:0, 15% of C15:0 and 12% of C12:0, respectively. Minor fatty acid were C4:0 and C13:0 also detected less than 7%. Under the consideration for the level of lipid production and the majority of a long chain fatty acid detection, R. toruloides TISTR 5149 with different fermentation parameters was chosen instead to utilize the industrial wastes.