Molecular species of phosphatidylethanolamine from continuous cultures of Saccharomyces pastorianus syn. carlsbergensis strains

Abstract

Saccharomyces pastorianus syn. carlsbergensis strain 34/70 is well known to be the most used strain for lager beer production. The difference between this strain and very closely related strain 34/78 is the latter's greater flocculating character. This single physiological trait can cause technical difficulties in beer production. The aim of this study was to determine whether lipid analysis by a combination of thin layer chromatography (TLC) with electrospray ionization mass spectrometry (ESI-MS) could be used as a strain-typing technique in order to distinguish S. pastorianus syn. carlsbergensis strain 34/70 from strain 34/78. Both strains (34/70 and 34/78) were harvested after continuous culture under standard conditions. Polar lipids were then extracted from lyophilized cultures and analysed by TLC in order to separate phospholipid families. Phosphatidylethanolamine (PE) was extracted and investigated using ESI-MS, to gain further information on individual molecular species. Using TLC analysis, lipids were separated corresponding to standards for PE, phosphatidylcholine (PC), phosphatidylglycerol (PG), cardiolipin (CL), phosphatidylserine (PS), phosphatidylinositol (PI), phosphatidic acid (PA) and sphingomyelin (SM). ESI-MS of the PE band, separated by TLC, showed that electrospray mass spectra were highly reproducible for repeat cultures. Novel findings were that both brewing strains displayed major phospholipid peaks with m/z 714, PE (34 : 2) m/z 742, PE (36 : 2) and m/z 758, PE (37 : 1). However, strain 34/78 had additional peaks of m/z 700, PE (33 : 2) and m/z 728, PE (35 : 2). Strain 34/70 had an extra peak with m/z 686 PE (32 : 2). We conclude that combined TLC/ESI-MS can distinguish between S. pastorianus syn. carlsbergensis 34/70 and 34/78 and may be a useful typing technique for differentiation of closely related yeast strains. This novel approach may aid quality assurance and could be suitable for yeast collections and larger industrial companies.

Structural Elucidation of Irish Ale Bioactive Polar Lipids with Antithrombotic Properties

“…Within the present study, bioactive PL extracts from a specific Irish ale with potent antithrombotic properties against PAF [ 14 ] were further fractionated into PL subclasses by TLC, and each TLC derived PL subclass was evaluated for its potential antithrombotic properties by assessing their putative inhibitory effect of PAF-induced aggregation of human platelets while the overall structures and fatty acid composition of the most bioactive PL subclasses of Irish ale PL extracts were elucidated through ESI-LC-MS analysis. Such an experimental approach, using preparative TLC for separating the PL into several subclasses and identifying molecular species of each subclass by ESI-LC-MS, has previously been effectively used in yeasts for beer production [ 28 ] and in other food sources [ 23 , 24 ].…”

“…More specifically, PL from the specific Irish ale assessed in the present study share similar TLC profiles of PL subclasses with those that were previously derived from TLC analyses of bioactive PL extracts from other types of Irish ale, lager and stout [ 14 ] and with other food sources [ 22 , 23 , 24 ]. Each PL subclass obtained by the TLC analysis of the Irish ale PL extracts was further assessed for its ability to inhibit PAF-induced platelet aggregation in hPRP as previously described [ 14 , 23 , 28 ]. TLC bands 2 and 3 corresponding to the PL subclasses of the SM family, and PC of Irish ale exhibited the strongest anti-PAF biological activities, followed by the TLC band 5 corresponding to the PE subclass of Irish ale that also showed a strong anti-PAF potency.…”

Developments in using fatty acids in fungal chemotaxonomy

“…Chemotaxonomy seems to mean different things to different people depending on their subject area. To a bacteriologist, chemotaxonomy has meant nucleotide, amino acid, carbohydrate or lipid based taxonomy (Fox et al, 1990), and to a mycologist working with yeasts, it often means a carbohydrate or lipid-based taxonomy (Tosch et al, 2006;Velazques et al, 2006).…”

Use of metabolomics for the chemotaxonomy of legume-associated Ascochyta and allied genera

“… 5 . Chemotaxonomy is one method of biological classification based on the similarity of chemical compounds such as carbohydrates, lipids, amino acids or secondary metabolites (SM) 14 15 16 . Filamentous fungi, especially ascomycetes, are known to produce a vast array of SMs such as terpenes, polyketides, non-ribosomal peptides, as well as many other small organic compounds of mixed biosynthetic origin.…”