Fatty acid mthyl esters produced by oleaginous yeast Yarrowia lipolytica QU21: an alternative for vegetable oils

摘要

Fatty acid mthyl esters produced by oleaginous yeast Yarrowia lipolytica QU21: an alternative for vegetable oils. An alternative for vegetable oil is microbial oil. There is, nowadays, an increasing interest in microbial lipidic compounds, called single cell oils (SCO), due to their several potential biotechnological applications, such as biodiesel production, food ingredients and antimicrobial activity, among others. Oleaginous yeasts are able to accumulate lipids up to 20% of their cellular dry weight, and some species can accumulate up to 70% of lipids. We have screened 86 yeast strains isolated from artisanal cheese using Nile red stain for the detection of intracellular lipid droplets by fluorescence microscopy, and 27% of them were promising for the production of microbial oil. Yarrowia lipolytica QU 21 was selected for comparison of five different methods of cell wall disruption for lipid extraction at a laboratory scale (dry biomass maceration, lysis with vortex and glass beads, ultrasonic bath and glass beads, maceration using liquid nitrogen, and liquid nitrogen followed by sonication). The method which showed the highest oil yield value (36%) was liquid nitrogen with sonication. Oil yield was highly influenced by the method used for cell wall lysis. Fatty acid methyl esters (FAME) composition of strain QU 21 after GC analysis was myristic acid (C14:0), myristoleic acid (C14:1), palmitic acid (C16:0), palmitoleic acid (C16:1), heptadecanoic acid (C17:1), stearic acid (C18:0) and oleic acid (C18:1).