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Micro-organisms such as bacteria, yeasts, molds and algae that accumulate lipid more than 20% of their biomass are called oleaginous. Microbial lipid has a lot of similarity to the oil obtained from plants and animals. Microbial lipids are renewable sources that can use for different purposes such as biodiesel production. Production of oil from yeasts has more advantages than plant’s oil. According to this, isolation of oleaginous yeast with high ability of lipid production is very valuable. In this investigation 176 yeasts were isolated. Between them 68 lipid producing yeasts were found that they were isolated from 34 soil samples. The strains were screened by an enrichment technique in glycerol and then Sudan black staining. After extraction of lipid by Bligh & Dyer method, best strain was selected which has lipid quantity, dry biomass and lipid productivity of 10.97g/l, 18.84g/l and 58.2% in optimized condition. Extracted lipid was analyzed by thin layer chromatography and FTIR spectroscopy.

Micro-organisms such as bacteria, yeasts, molds and algae that store lipid more than 20% of their biomass are called Oleaginous. Microbial lipid has a lot of similarity to the oil obtained from plants and animals and this similarity is valuable because it can be used for biodiesel production with many environmental benefits. Production of microbial oil is valuable when the cost of production is decreased by optimization of cultivation condition and using low cost substrate. In this study the effect of carbon and nitrogen sources on lipid production was investigated. These parameters have the most important effect on lipid production in many oleaginous types of yeast. Among the carbon sources which were evaluated, glucose leads to higher lipid content but from economical point of view rice bran was the best carbon source. Between nitrogen sources, yeast extract and ammonium sulfate exhibited higher lipid content. Rhodotorulla 110 had lipid content of 40%, 36% and 30% in glucose, xylose and bran as carbon source respectively with yeast extract and ammonium sulfate as nitrogen sources.