The aim of this study was to assess the phylogenetic relationships, ecology and ecophysiological characteristics of the dominant planktic algae in ice-covered lakes on James Ross Island (northeastern Antarctic Peninsula). Phylogenetic analyses of 18S rDNA together with analysis of ITS2 rDNA secondary structure and cell morphology revealed that the two strains belong to one species of the genus Monoraphidium (Chlorophyta, Sphaeropleales, Selenastraceae) that should be described as new in future. Immotile green algae are thus apparently capable to become the dominant primary producer in the extreme environment of Antarctic lakes with extensive ice-cover. The strains grew in a wide temperature range, but the growth was inhibited at temperatures above 20 °C, indicating their adaptation to low temperature. Preferences for low irradiances reflected the light conditions in their original habitat. Together with relatively high growth rates (0.4-0.5 day-1) and unprecedently high content of polyunsaturated fatty acids (PUFA, more than 70% of total fatty acids), it makes these isolates interesting candidates for biotechnological applications.

• Keywords
• Antarctica *, Ecology *, Fatty acids *, Ice-covered lakes *, Light *, Monoraphidium *, Phylogeny *, Temperature *,
• MeSH
• Biodiversity * MeSH
• Chlorophyta classification   genetics   metabolism   MeSH
• Phytoplankton classification   genetics   isolation & purification   metabolism   MeSH
• Adaptation, Physiological MeSH
• Lakes MeSH
• Ice Cover * MeSH
• Fatty Acids, Unsaturated metabolism   MeSH
• RNA, Ribosomal, 18S genetics   MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Antarctic Regions MeSH
• Names of Substances
• Fatty Acids, Unsaturated MeSH
• RNA, Ribosomal, 18S MeSH

Liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-MS/APCI) with reversed- and chiral phases was used for separation of triacylglycerols (TAG) from protozoan and mold. This study describes the separation and identification of odd numbered chains of regioisomers and enantiomers of triacylglycerols from different natural sources, i.e., the protozoan Khawkinea quartana and the mold Mortierella alpina. Using the above-mentioned separation methods and the synthesis of appropriate standards of TAG, we identified regioisomers and enantiomers of both even and odd numbered TAG. The biosynthesis of odd numbered TAG was found to be strictly stereospecific and to depend on the production microorganism, one enantiomer predominating in the protozoan and the other in the mold. It was proved that even numbered TAG are synthesized in a higher optical purity, which can be explained by a higher affinity of acyltransferases to the respective substrate, i.e., to even chain PUFA.

• MeSH
• Euglena chemistry   MeSH
• Mass Spectrometry methods   MeSH
• Mortierella chemistry   MeSH
• Triglycerides chemistry   isolation & purification   MeSH
• Chromatography, High Pressure Liquid methods   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Triglycerides MeSH

Liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-MS/APCI) with a chiral phase was used for separation of triacylglycerols (TAG) obtained either by organic synthesis or isolated from different algal species. We present chromatographic characteristics and tandem mass spectra of enantiomers and positional isomers (regioisomers) of C16, C18 and C20 polyunsaturated fatty acids. The retention time was found to depend on the structure of the given TAG, increasing with increasing number of double bonds and decreasing with increasing number of the carbons in TAG, with the exception of dieicosapentaenoyl-palmitoyl-glycerols.

• MeSH
• Chlorophyta chemistry   MeSH
• Mass Spectrometry methods   MeSH
• Molecular Structure MeSH
• Fatty Acids, Unsaturated analysis   chemistry   isolation & purification   MeSH
• Stereoisomerism MeSH
• Tandem Mass Spectrometry methods   MeSH
• Triglycerides analysis   chemistry   MeSH
• Chromatography, High Pressure Liquid methods   standards   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Fatty Acids, Unsaturated MeSH
• Triglycerides MeSH

Lipids form a significant part of animal organs and they are responsible for important biological functions, such as semi-permeability and fluidity of membranes, signaling activity, anti-inflammatory processes, etc. We have performed a comprehensive nontargeted lipidomic characterization of porcine brain, heart, kidney, liver, lung, spinal cord, spleen, and stomach using hydrophilic interaction liquid chromatography (HILIC) coupled to electrospray ionization mass spectrometry (ESI/MS) to describe the representation of individual lipid classes in these organs. Detailed information on identified lipid species inside classes are obtained based on relative abundances of deprotonated molecules [M-H](-) in the negative-ion ESI mass spectra, which provides important knowledge on phosphatidylethanolamines and their different forms of fatty acyl linkage (ethers and plasmalogens), phosphatidylinositols, and hexosylceramides containing nonhydroxy- and hydroxy-fatty acyls. The detailed analysis of identified lipid classes using reversed-phase liquid chromatography in the second dimension was performed for porcine brain to determine more than 160 individual lipid species containing attached fatty acyls of different acyl chain length, double-bond number, and positions on the glycerol skeleton. The fatty acid composition of porcine organs is determined by gas chromatography with flame ionization detection after the transesterification with sodium methoxide.

• MeSH
• Chromatography, Liquid methods   MeSH
• Chromatography, Gas methods   MeSH
• Phosphatidylethanolamines analysis   MeSH
• Phospholipids analysis   MeSH
• Spectrometry, Mass, Electrospray Ionization methods   MeSH
• Hydrophobic and Hydrophilic Interactions MeSH
• Liver chemistry   MeSH
• Kidney chemistry   MeSH
• Lipids analysis   chemistry   MeSH
• Fatty Acids analysis   MeSH
• Spinal Cord chemistry   MeSH
• Brain Chemistry MeSH
• Myocardium chemistry   MeSH
• Plasmalogens analysis   MeSH
• Lung chemistry   MeSH
• Swine MeSH
• Spleen chemistry   MeSH
• Stomach chemistry   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Phosphatidylethanolamines MeSH
• Phospholipids MeSH
• Lipids MeSH
• Fatty Acids MeSH
• Plasmalogens MeSH