title: Fast and accurate preparation fatty acid methyl esters by microwave-assisted derivatization in the yeast Saccharomyces cerevisiae.
abstract: We present a fast and accurate method for preparation of fatty acid methyl esters (FAMEs) using microwave-assisted derivatization of fatty acids present in yeast samples. The esterification of free/bound fatty acids to FAMEs was completed within 5 min, which is 24 times faster than with conventional heating methods. The developed method was validated in two ways: (1) through comparison with a conventional method (hot plate) and (2) through validation with the standard reference material (SRM) 3275-2 omega-3 and omega-6 fatty acids in fish oil (from the Nation Institute of Standards and Technology, USA). There were no significant differences (P>0.05) in yields of FAMEs with both validations. By performing a simple modification of closed-vessel microwave heating, it was possible to carry out the esterification in Pyrex glass tubes kept inside the closed vessel. Hereby, we are able to increase the number of sample preparations to several hundred samples per day as the time for preparation of reused vessels was eliminated. Pretreated cell disruption steps are not required, since the direct FAME preparation provides equally quantitative results. The new microwave-assisted derivatization method facilitates the preparation of FAMEs directly from yeast cells, but the method is likely to also be applicable for other biological samples.
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
authors.forename: Sakda
authors.initials: S
authors.lastname: Khoomrung
authors.forename: Pramote
authors.initials: P
authors.lastname: Chumnanpuen
authors.forename: Suwanee
authors.initials: S
authors.lastname: Jansa-ard
authors.forename: Intawat
authors.initials: I
authors.lastname: Nookaew
authors.forename: Jens
authors.initials: J
authors.lastname: Nielsen
mesh_terms: D004951:Esterification; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D007218:Industrial Microbiology / Q000379:methods*; D008738:Methyl Ethers / Q000032:analysis / Q000378:metabolism*; D008872:Microwaves; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects*
chemical_list: D005227:Fatty Acids; D008738:Methyl Ethers