Seasonally slowly melting mountain snowfields are populated by extremophilic microalgae. In alpine habitats, high-light sensitive, green phytoflagellates are usually observed in subsurface layers deeper in the snowpack under dim conditions, while robust orange to reddish cyst stages can be seen exposed on the surface. In this study, uncommon surface green snow was investigated in the High Tatra Mountains (Slovakia). The monospecific community found in the green surface bloom consisted of vegetative Chloromonas cells (Volvocales, Chlorophyta). Molecular data demonstrated that the field sample and the strain isolated and established from the bloom were conspecific, and they represent a new species, Chloromonas kaweckae sp. nov., which is described based on the morphology of the vegetative cells and asexual reproduction and on molecular analyses of the strain. Cells of C. kaweckae accumulated approximately 50% polyunsaturated fatty acids, which is advantageous at low temperatures. In addition, this new species performed active photosynthesis at temperatures close to the freezing point showed a light compensation point of 126 ± 22 μmol photons · m-2 · s-1 and some signs of photoinhibition at irradiances greater than 600 μmol photons · m-2 · s-1 . These data indicate that the photosynthetic apparatus of C. kaweckae could be regarded as adapted to relatively high light intensities, otherwise unusual for most flagellate stages of snow algae.

• Keywords
• biodiversity, cryoflora, environmental sample, fatty acids, fluorometry, vegetative stages,
• MeSH
• Chlorophyceae * MeSH
• Chlorophyta * physiology   MeSH
• Photosynthesis physiology   MeSH
• Cold Temperature MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Slovakia MeSH

Melting mountainous snowfields are populated by extremophilic microorganisms. An alga causing orange snow above timberline in the High Tatra Mountains (Poland) was characterised using multiple methods examining its ultrastructure, genetics, life cycle, photosynthesis and ecophysiology. Based on light and electron microscopy and ITS2 rDNA, the species was identified as Chloromonas krienitzii (Chlorophyceae). Recently, the taxon was described from Japan. However, cellular adaptations to its harsh environment and details about the life cycle were so far unknown. In this study, the snow surface population consisted of egg-shaped cysts containing large numbers of lipid bodies filled presumably with the secondary carotenoid astaxanthin. The outer, spiked cell wall was shed during cell maturation. Before this developmental step, the cysts resembled a different snow alga, Chloromonas brevispina. The remaining, long-lasting smooth cell wall showed a striking UV-induced blue autofluorescence, indicating the presence of short wavelengths absorbing, protective compounds, potentially sporopollenin containing polyphenolic components. Applying a chlorophyll fluorescence assay on intact cells, a significant UV-A and UV-B screening capability of about 30 and 50%, respectively, was measured. Moreover, intracellular secondary carotenoids were responsible for a reduction of blue-green light absorbed by chloroplasts by about 50%. These results revealed the high capacity of cysts to reduce the impact of harmful UV and high visible irradiation to the chloroplast and nucleus when exposed at alpine snow surfaces during melting. Consistently, the observed photosynthetic performance of photosystem II (evaluated by fluorometry) showed no decline up to 2100 μmol photons m-2 s-1. Cysts accumulated high contents of polyunsaturated fatty acids (about 60% of fatty acids), which are advantageous at low temperatures. In the course of this study, C. krienitzii was found also in Slovakia, Italy, Greece and the United States, indicating a widespread distribution in the Northern Hemisphere.

• Keywords
• UV-A radiation, UV-B radiation, astaxanthin, chlorophyll fluorescence, cysts, photosynthesis, polyunsaturated fatty acids, snow algae,
• Publication type
• Journal Article MeSH

High resolution electrospray ionization tandem mass spectrometry (HR-ESI-MS/MS) was used to analyze cardiolipins (Ptd2Gro) including their plasmalogen forms from three species of the anaerobic beer-spoilage bacterial genus Pectinatus. Cardiolipins including their plasmalogens were analyzed by HR-ESI-MS/MS on Orbitrap and almost 100 cardiolipins (i.e. tetra-acyl--Ptd2Gro, plasmenyl-tri-acyl--PlsPtd2Gro, and di-plasmenyl-di-acyl--Pls2Ptd2Gro) of three classes were identified. The structures of the molecular species that consist of various regioisomers and structurally similar compounds were revealed in detail. The high resolution mass spectrometry allowed the unambiguous structural assignment of Ptd2Gro, PlsPtd2Gro, and Pls2Ptd2Gro in the three species of Pectinatus, which contain predominantly odd numbered fatty acids.

• MeSH
• Spectrometry, Mass, Electrospray Ionization methods   MeSH
• Cardiolipins analysis   chemistry   MeSH
• Food Contamination MeSH
• Molecular Structure MeSH
• Pectinatus chemistry   MeSH
• Beer microbiology   MeSH
• Plasmalogens analysis   chemistry   MeSH
• Food Microbiology MeSH
• Tandem Mass Spectrometry methods   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Cardiolipins MeSH
• Plasmalogens MeSH

A total of 307 new compounds, natural, semisynthetic or synthetic, were isolated at the Institute of microbiology during the last twelve years. Due to the development of separation (chromatographic) methods and of analytical methods used to determine the chemical structure of these compounds, i.e. NMR, MS and X-ray diffraction, many new metabolites could be described.

• MeSH
• Biological Factors chemistry   isolation & purification   MeSH
• Peptides, Cyclic chemistry   isolation & purification   MeSH
• Enzymes chemistry   isolation & purification   MeSH
• Molecular Sequence Data MeSH
• Ergot Alkaloids chemistry   isolation & purification   MeSH
• Carbohydrate Sequence MeSH
• Carbohydrates chemistry   isolation & purification   MeSH
• Amino Acid Sequence MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Biological Factors MeSH
• Peptides, Cyclic MeSH
• Enzymes MeSH
• Ergot Alkaloids MeSH
• Carbohydrates MeSH