Chromosome-level genome assembly and annotation of the Patagonian toothfish Dissostichus eleginoides.

The Patagonian toothfish (Dissostichus eleginoides) belongs to the Actinopterygii class, and the suborder Notothenioidei, which lives in cold waters in the Southern Hemisphere. We performed assembly and annotation, and we integrated the Illumina short-read sequencing for polishinng, PacBio long-read sequencing for contig-level assembly, and Hi-C sequencing technology to obtain high-quality of chromosome-level genome assembly. The final assembly analysis resulted in a total of 495 scaffolds, a genome size of 844.

Selective transmission of airborne bacterial communities from the ocean to the atmosphere over the Northern Pacific Ocean.

This study simultaneously measured the taxonomic diversity of bacterial communities in both seawater and PM aerosol samples collected from the Northern Pacific Ocean during a cruise covering 7724 km between 37°N 126°E and 58°N 179°E. The relative abundance of Proteobacteria, Cyanobacteria, and Firmicutes were found to be more prevalent in aerosol samples (39 ± 16 %, 5.1 ± 1.

A novel simultaneous abatement of bromate and diphenyl phosphate using the freezing process.

The purification of bromate (BrO)-contaminated water has become a challenge because of its persistence and adverse effects. Furthermore, there has been concern over the release of byproducts, such as diphenyl phosphate (DPHP), from flame retardants in wastewater treatment plant (WWTP). In this study, we designed the water treatment system for the oxidation of DPHP accompanied by bromate (BrO) reduction via freezing the solution.

Exploring micropollutants in polar environments based on non-target analysis using LC-HRMS.

The routine use of chemicals in polar regions contributes to unexpected occurrence of micropollutants, with sewage discharge as a prominent pollution source. The aim of this study was to identify and quantify micropollutants in polar environments near potential point sources using non-target analysis (NTA) with liquid chromatography high-resolution mass spectrometry. Seawater samples were collected from Ny-Ålesund, Svalbard and Marian Cove, King George Island, in 2023.

Seasonal dynamics of airborne biomolecules influence the size distribution of Arctic aerosols.

Organic matter is crucial in aerosol-climate interactions, yet the physicochemical properties and origins of organic aerosols remain poorly understood. Here we show the seasonal characteristics of submicron organic aerosols in Arctic Svalbard during spring and summer, emphasizing their connection to transport patterns and particle size distribution. Microbial-derived organic matter (MOM) and terrestrial-derived organic matter (TOM) accounted for over 90% of the total organic mass in Arctic aerosols during these seasons, comprising carbohydrate/protein-like and lignin/tannin-like compounds, respectively.

Visible light-induced photocatalytic degradation of tetrabromobisphenol A on platinized tungsten oxide.

In this study, we investigated the degradation of the flame retardant tetrabromobisphenol A (TBBPA) using platinized tungsten oxide (Pt/WO), synthesized via a simple photodeposition method, under visible light. The results of degradation experiments show a significant enhancement in TBBPA degradation upon surface platinization of WO, with the degradation rate increasing by 13.4 times compared to bare WO.

Freezing-enhanced degradation of azo dyes in the chloride-peroxymonosulfate system.

In this study, we investigated the freezing-induced acceleration of dye bleaching by chloride-activated peroxymonosulfate (PMS). It has been observed that the oxidation of chloride by PMS generates a free chlorine species, such as hypochlorous acid (HOCl), under mild acidic and circumneutral pH condition. This process is the major reason for the enhanced oxidation capacity for electron-rich organic compounds (e.

Photodegradation of bisphenol A in water and ice: identification of products using three photosensitizers.

Bisphenol A (BPA) is a widespread organic micro-pollutant, found in most environments, including alpine and Arctic regions, and several matrices such as waters and aerosols. Polar regions are characterized by periods of intense irradiation with no sunset due to the continuous sunlight, while alpine areas, despite following the day-night cycle of mid-latitudes, also undergo strong irradiation. For such conditions, it is possible that a fraction of the BPA present in snow may degrade through direct photolysis, producing other unknown species with different environmental mobility and possible ecotoxic effects.

Interspecific Variations in the Internal Mercury Isotope Dynamics of Antarctic Penguins: Implications for Biomonitoring.

Mercury (Hg) biomonitoring requires a precise understanding of the internal processes contributing to disparities between the Hg sources in the environment and the Hg measured in the biota. In this study, we investigated the use of Hg stable isotopes to trace Hg accumulation in Adélie and emperor penguin chicks from four breeding colonies in Antarctica. Interspecific variation of ΔHg in penguin chicks reflects the distinct foraging habitats and Hg exposures in adults.

Responses of soil micro-eukaryotic communities to decadal drainage in a Siberian wet tussock tundra.

Climate warming holds the potential to cause extensive drying of wetlands in the Arctic, but the warming-drying effects on belowground ecosystems, particularly micro-eukaryotes, remain poorly understood. We investigated the responses of soil micro-eukaryotic communities, including fungi, protists, and microbial metazoa, to decadal drainage manipulation in a Siberian wet tundra using both amplicon and shotgun metagenomic sequencing. Our results indicate that drainage treatment increased the abundance of both fungal and non-fungal micro-eukaryotic communities, with key groups such as Ascomycota (mostly order Helotiales), Nematoda, and Tardigrada being notably abundant in drained sites.

Chromosome-level genome assembly and annotation of the Antarctica whitefin plunderfish Pogonophryne albipinna.

The Antarctic whitefin plunderfish Pogonophryne albipinna belongs to the family Artedidraconidae, a key component of Antarctic benthic ecosystems within the order Perciformes and the suborder Notothenioidei. While genome research on P. albipinna using short-read sequencing is available, high-quality genome assembly and annotation employing long-read sequencing have yet to be performed.

Freezing-Enhanced Photoreduction of Iodate by Fulvic Acid.

Iodate is a stable form of iodine species in the natural environment. This work found that the abiotic photosensitized reduction of iodate by fulvic acid (FA) is highly enhanced in frozen solution compared to that in aqueous solution. The freezing-induced removal of iodate by FA at an initial pH of 3.

Frozen Clay Minerals as a Potential Source of Bioavailable Iron and Magnetite.

Iron (Fe) is an essential micronutrient that affects biological production. Iron-containing clay minerals are an important source of bioavailable iron. However, the dissolution of iron-containing clay minerals at temperatures below the freezing point has not been investigated.

Molecular-level chemical composition of aerosol and its potential source tracking at Antarctic Peninsula.

Marine organic aerosols play crucial roles in global climatic systems. However, their chemical properties and relationships with various potential organic sources still need clarification. This study employed high-resolution mass spectrometry to investigate the identity, origin, and transportation of organic aerosols in pristine Antarctic environments (King Sejong Station; 62.

A chromosome-level reference genome of the Antarctic blackfin icefish Chaenocephalus aceratus.

The blackfin Icefish (Chaenocephalus aceratus) belongs to the family Channichthyidae and the suborder Notothenioidei which lives in the Antarctic. We corrected the mis-scaffolds in the previous linkage map results by Hi-C analysis to obtain improved results for chromosome-level genome assembly. The final assembly analysis resulted in a total of 3,135 scaffolds, a genome size of 1,065.

Detoxification of arsenite by iodide in frozen solution.

The oxidation of arsenite (As(III)) to arsenate (As(V)) has received significant attention because it helps mitigate the hazardous and adverse effects of As(III) and subsequently improves the effectiveness of arsenic removal. This study developed an efficient freezing technology for the oxidative transformation of As(III) based on iodide (I). For a sample containing a very low concentration of 20 μM As(III) and 200 μM I frozen at -20 °C, approximately 19 μM As(V) was formed after reaction for 0.

Reversible intracellular acidification and depletion of NTPs provide a potential physiological origin for centuries of dormancy in an Antarctic freshwater copepod.

A great diversity of crustacean zooplankton found in inland and coastal waters produce embryos that settle into bottom sediments to form an egg bank. Embryos from these banks can remain dormant for centuries, creating a reservoir of genetic diversity. A large body of literature describes the ecological and evolutionary importance of zooplankton egg banks.

Catalytic behavior of nitrous acid for acetaminophen transformation during the freezing process.

This study demonstrates the transformation of acetaminophen by reactive nitrous acid in a frozen solution and its abnormal stoichiometry. The chemical reaction between acetaminophen and nitrous acid (AAP/NO system) was negligible in the aqueous solution; however, the reaction rapidly progressed if the solution started to freeze. The ultrahigh performance liquid chromatography-electrospray ionization tandem mass spectrometry measurements showed that polymerized acetaminophen and nitrated acetaminophen were formed in the proceeding reaction.

Characterization of free L- and D-amino acids in size-segregated background aerosols over the Ross Sea, Antarctica.

The study of airborne chemical markers is crucial for identifying sources of aerosols, and their atmospheric processes of transport and transformation. The investigation of free amino acids and their differentiation between the L- and D- enantiomers are even more important to understand their sources and atmospheric fate. Aerosol samples were collected with a high-volume sampler with cascade impactor at Mario Zucchelli Station (MZS) on the coast of the Ross Sea (Antarctica) for two summer campaigns (2018/19 and 2019/20).

MnO-Induced Oxidation of Iodide in Frozen Solution.

Metal oxides play a critical role in the abiotic transformation of iodine species in natural environments. In this study, we investigated iodide oxidation by manganese dioxides (β-MnO, γ-MnO, and δ-MnO) in frozen and aqueous solutions. The heterogeneous reaction produced reactive iodine (RI) in the frozen phase, and the subsequent thawing of the frozen sample induced the gradual transformation of in situ-formed RI to iodate or iodide, depending on the types of manganese dioxides.