Analysis of Fatty Acid Content and Composition in Microalgae

Abstract

A method to determine the content and composition of total fatty acids present in microalgae is described. Fatty acids are a major constituent of microalgal biomass. These fatty acids can be present in different acyl-lipid classes. Especially the fatty acids present in triacylglycerol (TAG) are of commercial interest, because they can be used for production of transportation fuels, bulk chemicals, nutraceuticals (ω-3 fatty acids), and food commodities. To develop commercial applications, reliable analytical methods for quantification of fatty acid content and composition are needed. Microalgae are single cells surrounded by a rigid cell wall. A fatty acid analysis method should provide sufficient cell disruption to liberate all acyl lipids and the extraction procedure used should be able to extract all acyl lipid classes.With the method presented here all fatty acids present in microalgae can be accurately and reproducibly identified and quantified using small amounts of sample (5 mg) independent of their chain length, degree of unsaturation, or the lipid class they are part of. This method does not provide information about the relative abundance of different lipid classes, but can be extended to separate lipid classes from each other.The method is based on a sequence of mechanical cell disruption, solvent based lipid extraction, transesterification of fatty acids to fatty acid methyl esters (FAMEs), and quantification and identification of FAMEs using gas chromatography (GC-FID). A TAG internal standard (tripentadecanoin) is added prior to the analytical procedure to correct for losses during extraction and incomplete transesterification. Video LinkThe video component of this article can be found at

Photosynthetic efficiency and carbon partitioning in nitrogen-starved Scenedesmus obliquus

“…Biomass DW, dissolved nitrate, total fatty acid (TFA), and starch concentration were measured as described previously [6,22]. The absorption cross section was measured and calculated as described by Vejrazka et al [23] between 400 and 700 nm using a Shimadzu UV-2600 integrating sphere spectrophotometer.…”

Effect of cooling in the night on the productivity and biochemical composition of Tetraselmis suecica

“…The biochemical composition was determined following established methods: carbohydrates through the phenol-sulphuric acid method [24], proteins via the method which is based on the reaction of protein with alkaline copper tartrate solution and Folin reagent [25] and fatty acid extraction and quantification with gas chromatography [26].…”

Scale-down of CHO cell fed-batch cultures

“…Bovine serum albumin (BSA, Sigma-Aldrich) was used as a reference standard. The extraction, separation, and quantification of triacylglyceride (TAG) and polar lipids were performed as described by Breuer et al 76 using the sample preparation method 2. Lipid droplets in CHO cells were stained with BODIPY 505/515 (Invitrogen Molecular Probes, Carlsbad, CA) and visualized using a confocal laser scanning microscope (LSM510; Carl Zeiss, Jena, Germany), as described by Cooper et al 77 .…”