title: Determination and differentiation of triacylglycerol molecular species in Antarctic and non-Antarctic yeasts by atmospheric pressure-chemical ionization-mass spectrometry.
abstract: Yeast, particularly Saccharomyces cerevisiae, has long served as a model eukaryotic system for studies on the regulation of lipid metabolism. We developed a high performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry method for the detailed analysis of triacylglycerols (TAGs) in 14 species of yeast consisting of seven Antarctic yeasts (grown at 15°C and 5°C) and seven non-Antarctic yeasts (grown at 25°C and 15°C), the latter including 3 strains of S. cerevisiae. Analysis of TAG molecular species established that the sn-2 position was invariably occupied by an unsaturated fatty acyl moiety. In S. cerevisiae the preference was for oleic acid 18:1>palmitoleic acid 16:1, in Candida albicans, Cryptococcus humicolus and Rhodotorula mucilaginosa 18:1>linoleic acid 18:2 and in Zygosaccharomyces rouxii 18:2>18:1. In the Antarctic yeasts (Cryptococcus watticus, Cryptococcus victoriae, Cryptococcus nyarrowii, Leucosporidium antarcticum, Leucosporidium fellii, Candida psychrophila and Rhodotorula mucilaginosa) the general pattern was for the sn-2 position to be occupied by 18:1, 18:2 or linolenic acid 18:3. A trend towards synthesis of increased unsaturated fatty acid in TAGs was observed as the growth temperature was lowered. The application of principal component analysis demonstrated that the yeasts were differentiated into three distinct groups. One group consisted of the three S. cerevisiae strains, a second the other four non-Antarctic yeasts and the third the seven Antarctic yeasts. The data for the Antarctic yeasts, to the best of our knowledge, have not been previously reported.
authors.affiliation: School of Science and Technology, University of New England, Armidale, NSW 2351, Australia.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Bhuiyan
authors.forename: David
authors.initials: D
authors.lastname: Tucker
authors.forename: Kenneth
authors.initials: K
authors.lastname: Watson
mesh_terms: D000864:Antarctic Regions; D002851:Chromatography, High Pressure Liquid; D013058:Mass Spectrometry / Q000379:methods*; D025341:Principal Component Analysis; D013696:Temperature; D014280:Triglycerides / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D015003:Yeasts / Q000737:chemistry* / Q000502:physiology
chemical_list: D014280:Triglycerides
keywords: Antarctic yeast; Fatty acid; HPLC-APCI-MS; Mass spectrometry; Temperature; Triacylglycerol