Glycerol and rapeseed meal, two major by-products of biodiesel production, have been tested for possible
use as low-cost raw materials for the production of microbial bio-oil using the oleaginous yeast Rhodosporidium
toruloides. Using fed-batch fermentation with crude glycerol and a novel nitrogen rich nutrient
source derived from rapeseed meal as feed, it was shown that 13 g/L lipids could be produced, compared
with 9.4 g/L when crude glycerol was used with yeast extract. When 100 g/L pure glycerol was used, the
final lipid concentration was 19.7 g/L with the novel biomedium compared to 16.2 g/L for yeast extract.
The novel biomedium also resulted in higher lipid yields (0.19 g lipid/g glycerol consumed compared to
0.12 g/L) suggesting it provides a better carbon to nitrogen balance for accumulating lipids. FAMEs produced
from the microbial lipids indicated a high degree of unsaturation confirming that the fatty acids
produced from the novel biomedium have potential for biodiesel production.