Red, orange or green snow is the macroscopic phenomenon comprising different eukaryotic algae. Little is known about the ecology and nutrient regimes in these algal communities. Therefore, eight snow algal communities from five intensively tinted snow fields in western Spitsbergen were analysed for nutrient concentrations and fatty acid (FA) composition. To evaluate the importance of a shift from green to red forms on the FA-variability of the field samples, four snow algal strains were grown under nitrogen replete and moderate light (+N+ML) or N-limited and high light (−N+HL) conditions. All eight field algal communities were dominated by red and orange cysts. Dissolved nutrient concentration of the snow revealed a broad range of NH⁺₄ (<0.005–1.2 mg N l⁻¹) and only low PO³⁻₄ (<18 μg P l⁻¹) levels. The external nutrient concentration did not reflect cellular nutrient ratios as C:N and C:P ratios of the communities were highest at locations containing relatively high concentrations of NH⁺₄ and PO³⁻₄. Molar N:P ratios ranged from 11 to 21 and did not suggest clear limitation of a single nutrient. On a per carbon basis, we found a 6-fold difference in total FA content between the eight snow algal communities, ranging from 50 to 300 mg FA g C⁻¹. In multivariate analyses total FA content opposed the cellular N:C quota and a large part of the FA variability among field locations originated from the abundant FAs C18:1n-9, C18:2n-6, and C18:3n-3. Both field samples and snow algal strains grown under −N+HL conditions had high concentrations of C18:1n-9. FAs possibly accumulated due to the cessation of growth. Differences in color and nutritional composition between patches of snow algal communities within one snow field were not directly related to nutrient conditions. We propose that the highly patchy distribution of snow algae within and between snow fields may also result from differences in topographical and geological parameters such as slope, melting water rivulets, and rock formation.

The CCCryo Culture Collection of Cryophilic Algae is a diverse bioresource of mainly cold-adapted microalgae from polar environments. It currently comprises 518 strains of 178 species in 101 genera. Most strains were isolated from field samples collected during seven polar expeditions, mainly to Svalbard (Norway) and Antarctica. Almost 90% of the strains are cryophilic, with 33% of all strains being psychrophilic (obligate cryophilic) representing the “true” snow algae and 56% being psychrotrophic (non-obligate cryophilic), comprising other snow and permafrost algae from cold habitats. There are also some cultures of mosses, cyanobacteria, fungi and bacteria from cold or thermal environments. These strains are publicly available and serve as a rare bioresource for fundamental studies as well as for the development of commercial products. Basic studies address taxonomic and phylogenetic as well as physiological questions and genome and transcriptome research, whereas applied studies mostly address the capabilities of cryophilic algae to produce commercially interesting products for markets like food, feed and supplements, cosmetics, tools for molecular biology and diagnostics or food processing. Examples of strains studied for the production of valuable polyunsaturated omega-3 fatty acids like EPA, secondary carotenoids like astaxanthin, ice-structuring proteins, cold-active enzymes, UV-absorbing mycosporine-like amino acids and extracellular polymeric substances as form stabilizers are given and discussed in the context of customers’ acceptance, legal regulations for specific markets, technical feasibility of an industrial production process, potential profit and chances for the successful development of a commercial product.

The future robotic exploration missions to Mars—European Space Agency/Roscosmos's ExoMars2020 and National Aeronautics and Space Administration's Mars2020 rovers—will search for signs of extant or extinct life using, among other instruments, Raman spectrometers for the first time. The question remains whether organic biosignatures—such as pigments and cellular components—may be detected by this method. Evaluating their detection limit under simulated extraterrestrial conditions is therefore crucial for the success of future life detection missions. Ionizing radiation can be considered as the most deleterious factor for the long‐term preservation of potential biomarkers on Mars. Here, we report on the preservation potential of Raman signatures in the Antarctic strain CCCryo 231‐06 of the cyanobacterium Nostoc sp. after high doses of gamma irradiation. The carotenoids' signals, a well‐established biosignature model, dominate the Raman spectra at 532‐nm excitation wavelength due to resonance effects. But comparing their distribution and quantifying their preservation are still problematic in natural samples. To standardize the analyses, we successfully applied Raman mapping and signal‐to‐noise ratio masks to quantify the effects of irradiation. The typical in vivo Raman signatures of carotenoids could be detected after exposure to up to 56 kGy with significant deterioration in terms of signal coverage and signal‐to‐noise ratio. But they remained stable even after the highest dose of γ rays (117 kGy) tested in this study for colonies embedded in two different Martian mineral analogues. Data gathered during these ground‐based irradiation experiments contribute to interpret results from space experiments and will guide our search for life on Mars and other bodies of interest.

Single-cell sequencing is a powerful technology that provides the capability of analyzing a single cell within a population. This technology is mostly coupled with microfluidic systems for controlled cell manipulation and precise fluid handling to shed light on the genomes of a wide range of cells. So far, single-cell sequencing has been focused mostly on human cells due to the ease of lysing the cells for genome amplification. The major challenges that bacterial species pose to genome amplification from single cells include the rigid bacterial cell walls and the need for an effective lysis protocol compatible with microfluidic platforms. In this work, we present a lysis protocol that can be used to extract genomic DNA from both gram-positive and gram-negative species without interfering with the amplification chemistry. Corynebacterium glutamicum was chosen as a typical gram-positive model and Nostoc sp. as a gram-negative model due to major challenges reported in previous studies. Our protocol is based on thermal and chemical lysis. We consider 80% of single-cell replicates that lead to >5 ng DNA after amplification as successful attempts. The protocol was directly applied to Gloeocapsa sp. and the single cells of the eukaryotic Sphaerocystis sp. and achieved a 100% success rate.