30 µL CHCl3 and 70 µL trimethylsulfoniumhydroxid (0.25 M in MeOH) were added, mixed thoroughly and incubated for 60 min at 60 °C. The analysis was carried out on a Focus GC coupled to a Polaris Q mass spectrometer (both Thermo Fisher Scientific, Dreieich, Germany). A HP-5 MS column (30 m; 0.25 mm i.d.; 0.25 µm film thickness; GGA, Moers, Germany) and the following temperature program were used: 150 °C (4 min), 2 °C/min, 250 °C. Sample was injected in splitless mode, injector temperature was set to 250 °C and Inhibitors,research,lifescience,medical transfer capillary temperature
was 280 °C. The following mass spectrometric parameters were used: acquisition delay 3 min, ion source temperature 200 °C, full scan range m/z 35–500, EI = 70 eV, in positive ionization mode. 3.5. Data Evaluation For conversion of raw data files into text files, the implemented file converter of XcaliburTM (Thermo Fisher Scientific) was used. These Inhibitors,research,lifescience,medical files were analyzed by the “Profiler-Merger-Viewer”
software package described in detail by Hein et al. [14]. This application is written in JavaTM (Sun Microsystems) and uses Microsoft ExcelTM as output format. 4. Conclusions In this comparative lipidomic study, the GP profiles of five phylogenetically different yeasts were investigated. Inhibitors,research,lifescience,medical The aim of the study was to answer the question as to whether these organisms possess a characteristic GP pattern and if genetic relation can also be recognized by analysis of the GP profile. Based on the HPLC/ESI-LIT-FTICRMS Inhibitors,research,lifescience,medical method and the data processing by the Profiler-Merger-Viewer
software, a minimum of 106 GP species (in S. cerevisiae), covering nine major GP AVL 301 classes was relatively quantified. The study enabled a detailed insight into the species identity and distribution of relative amounts within a GP class. Moreover, the relative amounts of the GP classes in the examined yeast were also determined. Inhibitors,research,lifescience,medical The results are in good agreement with a recently published comprehensive study by Ejsing et al. [11]. Comparison of the five yeast strains revealed characteristic GP profiles, which were reproducible in biological replicates. Even the closely related yeast strains S. cerevisiae and S. bayanus show—notwithstanding their analogies in species identity and distribution—significant differences in not the relative amount of these species. This deep insight allows the conclusion that characteristic genetic traits as well as phylogenetic relationships are reflected in the GP profile of organisms, although the lipidome describes the actual status of an organism. It has to be noted again that the basis of these results are comparable environmental conditions as well as equal nutrients. The obtained results are in accordance with existing genomic data. In particular, the number of double bonds found in GPs species seems to be yeast strain-specific and correlates well with the presence or absence of desaturase-encoding genes in the genome.