Psychrophilic pucciniomycotinous yeasts inhabit snowfields and glacial ecosystems worldwide, yet their ecological role remains unclear. We isolated a clonal strain of Phenoliferia psychrophenolica (LCC-F-001-001) from an alpine red snowfield. Its 42-Mbp genome contains 11,523 genes, including 37 ice-binding protein genes, the highest number recorded in fungi, mainly acquired through horizontal transfers. This yeast tolerates freezing, grows optimally at 10 °C and forms pseudohyphae above 15 °C. Known to assimilate phenol and small metabolites, we found LCC-F-001-001 also hydrolyzes carotenoid and phenolic pigments from snow and glacier ice algae. LCC-F-001-001 genome encodes ~ 500 carbohydrate-active enzymes, ranking among the most catalytically versatile sequenced Microbotryomycetes, alongside a related permafrost species. P. psychrophenolica and related fungi are therefore key players in snow and ice ecosystems, capable of degrading organic molecules in snowfields and glaciers, likely during algal bloom declines, and connecting the carbon cycle between cryospheric environments and soils through their exceptional metabolic adaptability.

• MeSH
• Basidiomycota * genetics   metabolism   physiology   MeSH
• Ecosystem * MeSH
• Phylogeny MeSH
• Genome, Fungal MeSH
• Ice MeSH
• Ice Cover * microbiology   MeSH
• Snow * microbiology   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Ice MeSH

In this study, we used microscopic, spectroscopic, and molecular analysis to characterize endolithic colonization in gypsum (selenites and white crystalline gypsum) from several sites in Sicily. Our results showed that the dominant microorganisms in these environments are cyanobacteria, including: Chroococcidiopsis sp., Gloeocapsopsis pleurocapsoides, Gloeocapsa compacta, and Nostoc sp., as well as orange pigmented green microalgae from the Stephanospherinia clade. Single cell and filament sequencing coupled with 16S rRNA amplicon metagenomic profiling provided new insights into the phylogenetic and taxonomic diversity of the endolithic cyanobacteria. These organisms form differently pigmented zones within the gypsum. Our metagenomic profiling also showed differences in the taxonomic composition of endoliths in different gypsum varieties. Raman spectroscopy revealed that carotenoids were the most common pigments present in the samples. Other pigments such as gloeocapsin and scytonemin were also detected in the near-surface areas, suggesting that they play a significant role in the biology of endoliths in this environment. These pigments can be used as biomarkers for basic taxonomic identification, especially in case of cyanobacteria. The findings of this study provide new insights into the diversity and distribution of phototrophic microorganisms and their pigments in gypsum in Southern Sicily. Furthemore, this study highlights the complex nature of endolithic ecosystems and the effects of gypsum varieties on these communities, providing additional information on the general bioreceptivity of these environments.

• Keywords
• cyanobacteria, endoliths, green algae, gypsum, metagenomics, phototrophs,
• Publication type
• Journal Article MeSH

Snow algae are photosynthetic microbes that inhabit the melting snow surface in alpine and polar regions. We analyzed the pigment and species composition of colored snow collected on Mt. Tateyama in Japan during the melting seasons of 2015 and 2016. High-performance liquid chromatographic analyses of the pigments extracted from the colored snow showed that their composition varied within the study area and were classified into four types: Type A (astaxanthin-monoester dominant), Type B (medium astaxanthin-monoester content), Type C (abundant primary carotenoids and free-astaxanthin), and Type D (abundant primary carotenoids and astaxanthin diesters). Types A and B were most commonly observed in the study area, whereas Types C and D appeared only at specific sites. Analysis of the 18S ribosomal RNA (18S rRNA) gene revealed six major amplicon sequence variants (ASVs) of snow algae, belonging to the Sanguina, Chloromonas, and Chlainomonas groups. The relative abundance of the algal ASVs showed that Sanguina was dominant (>48%) in both Types A and B, suggesting that the difference in astaxanthin abundance between the two types was caused by the production of pigments in the algal cells. The algal community structures of Types C and D differed from those of Types A and B, indicating that the primary carotenoids and astaxanthin diesters were derived from certain algal species in these types. Therefore, astaxanthin-rich Sanguina algae mostly induced the red snow that appeared widely in this alpine area; however, they were partially dominated by Chloromonas or Chlainomonas algae, causing different pigment compositions.

• Keywords
• 18S rRNA, Chloromonas, Sanguina, astaxanthin, phylogenetic analysis, pigment composition, red snow, snow algae,
• Publication type
• Journal Article MeSH

Slowly melting snowfields in mountain and polar regions are habitats of snow algae. Orange blooms were sampled in three European mountain ranges. The cysts within the blooms morphologically resembled those of Chloromonas nivalis (Chlorophyceae). Molecular and morphological traits of field and cultured material showed that they represent a new species, Chloromonas hindakii sp. nov. The performance of photosystem II was evaluated by fluorometry. For the first time for a snow alga, cyst stages collected in a wide altitudinal gradient and the laboratory strain were compared. The results showed that cysts were well adapted to medium and high irradiance. Cysts from high light conditions became photoinhibited at three times higher irradiances (600 µmol photons m-2 s-1) than those from low light conditions, or likewise compared to cultured flagellates. Therefore, the physiologic light preferences reflected the conditions in the original habitat. A high content of polyunsaturated fatty acids (about 60% of total lipids) and the accumulation of the carotenoid astaxanthin was observed. They are regarded as adaptations to cope with extreme environmental conditions of snow that include low temperatures, freeze-thaw cycles, and variable light intensity. The intraspecific ability of adaptation of the photosynthetic apparatus to different irradiance regimes seems to be advantageous for thriving in different snow habitats.

• Keywords
• astaxanthin, cryoflora, cysts, environmental sample, fatty acids, photosynthesis,
• Publication type
• Journal Article MeSH

We present a comparison of the performance of four miniature portable Raman spectrometers for the discrimination of carotenoids in samples of carotene-producing microorganisms. Two spectrometers using a green laser allowing to obtain Resonance Raman (or pre-Resonance Raman) signals, one instrument with a 785 nm laser, and a recently developed Portable Sequentially Shifted Excitation Raman spectrometer (PSSERS) were used for identifying major pigments of different halophilic (genera Halobacterium, Halorubrum, Haloarcula, Salinibacter, Ectothiorhodospira, Dunaliella) and non-halophilic microorganisms (Micrococcus luteus, Corynebacterium glutamicum). Using all the tested instruments including the PSSERS, strong carotenoids signals corresponding to the stretching vibrations in the polyene chain and in-plane rocking modes of the attached CH3 groups were found at the correct positions. Raman spectra of carotenoids can be obtained from different types of microbiological samples (wet pellets, lyophilized culture biomass and pigment extracts in organic solvents), and can be collected fast and without time-consuming procedures.

• Keywords
• Corynebacterium, Halobacterium, Halorubrum, Salinibacter, exobiology, halophiles, portable Raman spectrometers, portable sequentially shifted excitation Raman spectrometer,
• Publication type
• Journal Article MeSH