4. Conclusions
The use of raw glycerol was beneficial for the production of carotenoids
by S. ruberrimus H110 in comparison to pure glycerol, and
this was attributed to the presence of fatty acids that did not react
during the transesterification process. Besides the higher yield and
productivity, the proportion of torularhodin, the main carotenoid
produced by S. ruberrimus, increased from 59% to 69%. The supplementation
of individual fatty acids (palmitic, stearic, oleic and linoleic
acids) to pure glycerol provided a similar effect on the
production of total carotenoids, and the presence of palmitic and
oleic acids also enhanced the proportion of torularhodin.