Thesis (M.Sc.) - Cairo University - Faculty of Agriculture - Department of Microbiology

Microbial lipid has high similarity to the oil obtained from plants and animals in type and composition. Production of oil from yeasts must be economical, so optimization of the cultivation conditions to produce higher production must be done. Lipomyces starkeyi was used for lipid production as a standard strain. Native oleaginous yeast, Rhodosporidium toruloides was isolated from soil and screened. This thesis studied effect of cell disruption methods and different types of solvent systems for lipid extraction. Several pre-production medium and production medium were studied for optimizing lipid production Also, the best carbon and nitrogen source was studied for lipid production. The research was conducted to design process optimization for condition factors through robust Taguchi design to identify the best parameters setting for lipid production. Analyzing of Taguchi data obtained the best level for each factor, that allow to form new NLM for each strain led to increase lipid contents reached 70.08 and 55.42% for R. toruloides and L. starkeyi, respectively. GC-MS was used for identifying and confirming the production of microbial oil in this study. Palmitic acid and oleic acid were major compounds for both strains. So, using R. toruloides in the economic production of lipids is recommended, and applies Taguchi design for more optimization processes

Issued also as CD