Isolation and molecular identification of Rhodotorula musilaginosa and its potential for applications in biodiesel production

Microbial lipid composition is similar to the oil obtained from plants and animals. Although vegetable oils were originally used for producing biodiesel, high costs of the process encouraged industries to use  microbial lipids as biodiesel sources. This study was conducted to isolate yeast strains with high lipid productivity, to optimize the extraction process of produced lipid and to convert the lipids to biodiesel.
In this study, after isolation of the yeast Rhodotorula, the productivity of microbial lipid in nitrogen limited condition, rice straw and wheat bran hydrolyzate was evaluated. The products were analyzed based on Gas Chromatography-Mass Spectrometry technique (GC-MS). The lipid production was optimized by two techniques (one factorial and Taguchi method) and the results were compared. At the end, the yeast strain was identified using polymerase chain reaction (PCR) techniques.
The strain isolated from this study was identified as Rhodotorula musilaginosa. The strain had high lipid production and dry biomass of 10.97 g/l and 18.84 g/l in optimized conditions, respectively. The highest fatty acids were Palmitic acid (18.51%) and Oleic acid (67.29%).
The results obtained in this study indicate that there are valuable native strains in our country that they can be used in different industries , especially biodiesel production.