A Comprehensive Study of Lipids from Antarctic and non-Antarctic Yeasts Using HPLC-MS Methodology

Abstract

Aim: A comprehensive analysis of the lipid profile [fatty acids, phospholipids (PL) and triacylglycerols (TAG), including the molecular species of PL and TAG] of 14 strains of yeast, seven designated as Antarctic and seven designated as non-Antarctic. These strains were: Antarctic: 'Cryptococcus watticus' CBS 9496, 'Cr. victoriae' CBS 8685, 'Cr. nyarrowii' CBS 8805, 'Leucosporidium antarcticum' CBS 8927, 'L. fellii' CBS 7287, 'Rhodotorula mucilaginosa' UNE 130a and 'Candida psychrophila' CBS 5956. Non-Antarctic: 'Cr. humicolus' ATCC 9949, 'C. albicans' ATCC 10231, 'R. mucilaginosa' ATCC 66034, 'Zygosaccharomyces rouxii' ATCC 2623, 'Saccharomyces cerevisiae' ATCC 18824, 'S. cerevisiae' ATCC 26603 and 'S. cerevisiae' ATCCC 26422. Methods: Cells were grown at 25°C or at 15°C for the non-Antarctic yeasts and at 15oC or at 5oC for the Antarctic yeasts. Lipids were isolated and total fatty acid compositions were analysed by Gas Chromatography-Mass Spectrometry. Phospholipid classes and their molecular species were determined by High Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (HPLC-ESI-MS). The regiospecific position of acyl groups of phospholipid molecular species was determined using ESI-MS-MS. Triacylglycerols and Diacylglycerols and their molecular species (nature of the fatty acid moieties in the sn-2 and sn-1,3 positions) were determined by HPLC-Atmospheric Pressure Chemical Ionization-Mass Spectrometry (HPLC-APCI-MS). ... Significance and Impact of the Studies: These are the first reports on detailed analyses of phospholipid and triacylglycerol molecular species in Antarctic yeasts. Moreover, they also provide new insights into the lipid components of non-Antarctic yeasts which to date have been largely concentrated on 'S. cerevisiae'. The data also provide novel information as to subtle but key changes in lipid molecular species in response to temperature.