Antarctic Soils Research Articles

Unravelling the genetic potential for hydrocarbon degradation in the sediment microbiome of Antarctic islands.

Hydrocarbons may have a natural or anthropogenic origin and serve as a source of carbon and energy for microorganisms in Antarctic soils. Herein, 16S rRNA gene and shotgun sequencing were employed to characterize taxonomic diversity and genetic potential for hydrocarbon degradation of the microbiome from sediments of sites located in two Antarctic islands subjected to different temperatures, geochemical compositions, and levels of presumed anthropogenic impact, named: Crater Lake/Deception Island (pristine area), Whalers Bay and Fumarole Bay/Deception Island (anthropogenic-impacted area), and Hannah Point/Livingston Island (anthropogenic-impacted area). Hydrocarbon concentrations were measured for further correlation analyses with biological data. The majority of the hydrocarbon-degrading genes were affiliated to the most abundant bacterial groups of the microbiome: Proteobacteria and Actinobacteria. KEGG annotation revealed 125 catabolic genes related to aromatic hydrocarbon (styrene, toluene, ethylbenzene, xylene, naphthalene, and polycyclic hydrocarbons) and aliphatic (alkanes and cycloalkanes) pathways. Only aliphatic hydrocarbons, in low concentrations, were detected in all areas, thus not characterizing the areas under study as anthropogenically impacted or nonimpacted. The high richness and abundance of hydrocarbon-degrading genes suggest that the genetic potential of the microbiome from Antarctic sediments for hydrocarbon degradation is driven by natural hydrocarbon occurrence.

Experimental warming increases fungal alpha diversity in an oligotrophic maritime Antarctic soil.

The climate of maritime Antarctica has altered since the 1950s. However, the effects of increased temperature, precipitation and organic carbon and nitrogen availability on the fungal communities inhabiting the barren and oligotrophic fellfield soils that are widespread across the region are poorly understood. Here, we test how warming with open top chambers (OTCs), irrigation and the organic substrates glucose, glycine and tryptone soy broth (TSB) influence a fungal community inhabiting an oligotrophic maritime Antarctic fellfield soil. In contrast with studies in vegetated soils at lower latitudes, OTCs increased fungal community alpha diversity (Simpson's index and evenness) by 102-142% in unamended soil after 5 years. Conversely, OTCs had few effects on diversity in substrate-amended soils, with their only main effects, in glycine-amended soils, being attributable to an abundance of Pseudogymnoascus. The substrates reduced alpha and beta diversity metrics by 18-63%, altered community composition and elevated soil fungal DNA concentrations by 1-2 orders of magnitude after 5 years. In glycine-amended soil, OTCs decreased DNA concentrations by 57% and increased the relative abundance of the yeast Vishniacozyma by 45-fold. The relative abundance of the yeast Gelidatrema declined by 78% in chambered soil and increased by 1.9-fold in irrigated soil. Fungal DNA concentrations were also halved by irrigation in TSB-amended soils. In support of regional- and continental-scale studies across climatic gradients, the observations indicate that soil fungal alpha diversity in maritime Antarctica will increase as the region warms, but suggest that the accumulation of organic carbon and nitrogen compounds in fellfield soils arising from expanding plant populations are likely, in time, to attenuate the positive effects of warming on diversity.

Temperature and pH Profiling of Extracellular Amylase from Antarctic and Arctic Soil Microfungi

While diversity studies and screening for enzyme activities are important elements of understanding fungal roles in the soil ecosystem, extracting and purifying the target enzyme from the fungal cellular system is also required to characterize the enzyme. This is, in particular, necessary before developing the enzyme for industrial-scale production. In the present study, partially purified α-amylase was obtained from strains of Pseudogymnoascus sp. obtained from Antarctic and Arctic locations. Partially purified α-amylases from these polar fungi exhibited very similar characteristics, including being active at 15 °C, although having a small difference in optimum pH. Both fungal taxa are good candidates for the potential application of cold-active enzymes in biotechnological industries, and further purification and characterization steps are now required. The α-amylases from polar fungi are attractive in terms of industrial development because they are active at lower temperatures and acidic pH, thus potentially creating energy and cost savings. Furthermore, they prevent the production of maltulose, which is an undesirable by-product often formed under alkaline conditions. Psychrophilic amylases from the polar Pseudogymnoascus sp. investigated in the present study could provide a valuable future contribution to biotechnological applications.

Freeze–thaw cycles affecting rheological properties of Antarctic soils

Antarctic soils are heavily affected by climate change in terms of properties and ecosystem functions. With increasing global temperatures, the frequency of freeze and thaw cycles of Antarctic soils will increase, thus affecting their mechanical behavior, with varying responses in erosion. This study quantitatively evaluated the effect of increasing frequency of freezing-thawing (F-T) cycles on rheological properties of four soils from the maritime Antarctica. Using an amplitude sweep test, the effects of 1, 5 and 9F-T cycles on soil micromechanics were evaluated and compared to a reference soil without F-T. These rheological parameters were determined: (i) the linear viscoelastic strain interval (LVR) (γLVR), (ii) the shear stress at the end of the LVR (τLVR), (iii) the maximum shear stress (τmax), (iv) the strain at the yield point (γYP), and (v) the storage and loss modulus at the yield point (G'YP). F-T cycles influenced soil rheological properties. Higher F-T frequency either increased or decreased γLVR and γYP, depending on the soil material. A 35% increase in τLVE occurred after one F-T cycle; however, at the fifth cycle a decrease of approximately 27% occurred, when compared to one cycle treatment, reaching similar values of no F-T. But after nine cycles, τLVE increased again by approximately 29% compared to previous treatment. The resistance and elasticity of the Antarctic soil microstructure showed great variation among the different soils, while soils with different textures behaved similarly for some rheological properties. Rheometry was confirmed as a method with little soil material consumption, however, soil rheology of Antarctic soils requires further studies to disentangle its interactions with soil chemical properties.

Relationships between concentrations of mercury and organic carbon in soils allow the identification of Antarctic ice-free areas with enhanced deposition of the metal

Antarctica is a sink for mercury (Hg) and plays an important role in the global Hg cycle. Knowledge about the environmental fate of Hg in Antarctic terrestrial ecosystems, however, remains highly restricted. In this study, we investigated soil Hg in samples from three areas located across a wide latitudinal range from about 62°S to over 74°S with very different climatic and environmental conditions and different potential (natural and anthropogenic) sources of Hg. The highest Hg levels were found in soils beneath mosses and ornithogenic soils in the Antarctic Peninsula, whereas extremely low values were found in coastal East Antarctica. Total Hg concentrations in soil samples from the three study areas were always closely related to those of organic carbon (OC). In corroborating the results of previous studies, this large-scale survey strongly suggests that OC is a dominant driver affecting Hg distribution in Antarctic soils. The observed linear relationship between Hg and OC concentrations, also supported by available literature data, probably, has a general relevance for Antarctic soils, and allows to identify samples affected by enhanced Hg deposition from anthropogenic or natural sources. In providing a better understanding of the biogeochemical cycle of Hg in Antarctic terrestrial ecosystems, this study suggests that soil OC content must be considered to assess Hg distribution patterns in Antarctic soils. In samples (including those of lacustrine sediments, planktonic, and benthic algal mats) unaffected by an accentuated deposition of Hg, the value of the ratio [Hg ng/g]/[OC %] appears to be less than ∼ 11.

Arthrobacter polaris sp. nov., a new cold-adapted member of the family Micrococcaceae isolated from Antarctic fellfield soil.

An aerobic, Gram-stain-positive and non-spore-forming strain, designated C1-1T, was isolated from a fellfield soil sample collected from frost-sorted polygons on Jane Col, Signy Island, Maritime Antarctic. Cells with a size of 0.65-0.9×1.2-1.7 µm have a flagellar motile apparatus and exhibit a rod-coccus growth cycle. Optimal growth conditions were observed at 15-20 °C, pH 7.0 and NaCl concentration up to 0.5 % (w/v) in the medium. The 16S rRNA gene sequence of C1-1T showed the highest pairwise similarity of 98.77 % to Arthrobacter glacialis NBRC 113092T. Phylogenetic trees based on the 16S rRNA and whole-genome sequences revealed that strain C1-1T belongs to the genus Arthrobacter and is most closely related to members of the 'Arthrobacter psychrolactophilus group'. The G+C content of genomic DNA was 58.95 mol%. The original and orthologous average nucleotide identities between strain C1-1T and A. glacialis NBRC 113092T were 77.15 % and 77.38 %, respectively. The digital DNA-DNA relatedness values between strain C1-1T and A. glacialis NBRC 113092T was 21.6 %. The polar lipid profile was composed mainly of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and an unidentified glycolipid. The predominant cellular fatty acids were anteiso-C15 : 0 (75 %) and anteiso-C17 : 0 (15.2 %). Menaquinone MK-9(H2) (86.4 %) was the major respiratory quinone in strain C1-1T. The peptidoglycan type was determined as A3α (l-Lys-l-Ala3; A11.6). Based on all described phylogenetic, physiological and chemotaxonomic characteristics, we propose that strain C1-1T (=DSM 112353T=CCM 9148T) is the type strain of a novel species Arthrobacter polaris sp. nov.

Knufia obscura sp. nov. and Knufia victoriae sp. nov., two new species from extreme environments.

Six strains of black meristematic fungi were isolated from Antarctic soils, gasoline car tanks and from the marine alga Flabellia petiolata. These fungi were characterized by morphological, physiological and phylogenetic analyses. According to the maximum-likelihood analysis reconstructed with ITS and LSU sequences, these strains belonged to the genus Knufia. Knufia obscura sp. nov. (holotype CBS 148926) and Knufia victoriae sp. nov. (holotype CBS 149015) are proposed as two novel species and descriptions of their morphological, physiological and phylogenetic features are presented. Based on the maximum-likelihood analyses, K. obscura was closely related to Knufia hypolithi (99 % bootstrap support), while K. victoriae clustered in the clade of Knufia cryptophialidica and Knufia perfecta (93 % bootstrap support). Knufia victoriae, recorded in Antarctic soil samples, had a psychrophilic behaviour, with optimal growth between 10 and 15 °C and no growth recorded at 20 °C. Knufia obscura, from a gasoline car tank and algae, displayed optimal growth between 20 and 25 °C and was more tolerant to salinity than K. victoriae.

Influence of marine vertebrates on organic matter, phosphorus and other chemical element levels in Antarctic soils

The presence of marine vertebrates in dense reproductive colonies and other aggregations contributes to the input of organic matter and nutrients into the local environment and it is believed that chemical elements are subsequently remobilized from the excreta of these animals. In this study, we investigated the influence of marine vertebrates on trace elements levels (As, Cd, Co, Cu, Fe, Li, Lu, Mg, Mn, Ni, Pb, Sb, Sc, Se, Sm, Sn, Sr, Tb, U and Zn), nutrient (total phosphorus) and soil organic matter (SOM) content from five locations with and without the presence of seabirds and marine mammals in Admiralty Bay, King George Island, South Shetland Islands, Antarctica. Soils were acid digested using a microwave digestion system, elements were quantified using inductively coupled plasma mass spectrometry and SOM was calculated by loss-on-ignition. The non-influenced and vertebrate-influenced soils had similar concentrations of most of the trace elements assessed, however, we observed a significant increase in SOM and P that was positively correlated with the concentrations of As, Cd, Se, Sr and Zn. Although marine vertebrates did not appear to significantly increase the elemental concentrations in the soils examined here, there is a clear evidence of selective enrichment indicating a zoogenic influence. Comparing our results with other studies, we conclude that soil elemental levels are result from an interplay between local geology, vertebrate diet and colony size. Further studies with increased sample size are required to obtain a better understanding of the influence of marine vertebrates on chemical element levels in Antarctic soils.

A Draft Mitogenome of Plectus Murrayi.

Plectus murrayi is a free-living microbivorous nematode endemic to Antarctic soils. Our draft assembly of its mitogenome was 15,656 bp long, containing 12 protein-coding, eight transfer RNA (tRNA), and two ribosomal RNA (rRNA) genes. Mitophylogenomic analyses extend our understanding of mitochondrial evolution in Nematoda.

Biomarkers in the Atacama Desert along the moisture gradient and the depth in the hyperarid zone: Phosphatase activity as trace of microbial activity

AbstractMicrobiological activities can be detected in various extreme environments on Earth, which suggest that extraterrestrial environments, such as on Mars, could host life. There have been proposed a number of biomarkers to detect extant life mostly based on specific molecules. Because terrestrial organisms have catalytic proteins (enzymes), enzymatic activity may also be a good indicator to evaluate biological activities in extreme environments. Phosphatases are essential for all terrestrial organisms because phosphate esters are ubiquitously used in genetic molecules (DNA/RNA) and membranes. In this study, we evaluated microbial activity in soils of the Atacama Desert, Chile, by analysing several biomarkers, including phosphatase activity. Phosphatases extracted with Tris buffer were assayed fluorometrically using 4-methylumbelliferyl phosphate as a substrate. The horizontal distribution of phosphatase activity and other parameters in soils from the Atacama Desert showed that phosphatase activity was positively correlated with amino acid concentration and colony-forming units and negatively correlated with precipitation amount. We found consistent that biochemical indicators including phosphatase significantly decreased in the extreme hyper-arid zone where rainfall of <25 mm year−1. The results were compared with phosphatase activities detected in extreme environments, such as submarine hydrothermal systems and Antarctic soils, as well as soils from ordinary environments. Overall, our results suggested that phosphatase activity could be a good indicator for evaluating biological activities in extreme environments.

Atmospheric chemosynthesis is phylogenetically and geographically widespread and contributes significantly to carbon fixation throughout cold deserts

Cold desert soil microbiomes thrive despite severe moisture and nutrient limitations. In Eastern Antarctic soils, bacterial primary production is supported by trace gas oxidation and the light-independent RuBisCO form IE. This study aims to determine if atmospheric chemosynthesis is widespread within Antarctic, Arctic and Tibetan cold deserts, to identify the breadth of trace gas chemosynthetic taxa and to further characterize the genetic determinants of this process. H2 oxidation was ubiquitous, far exceeding rates reported to fulfill the maintenance needs of similarly structured edaphic microbiomes. Atmospheric chemosynthesis occurred globally, contributing significantly (p < 0.05) to carbon fixation in Antarctica and the high Arctic. Taxonomic and functional analyses were performed upon 18 cold desert metagenomes, 230 dereplicated medium-to-high-quality derived metagenome-assembled genomes (MAGs) and an additional 24,080 publicly available genomes. Hydrogenotrophic and carboxydotrophic growth markers were widespread. RuBisCO IE was discovered to co-occur alongside trace gas oxidation enzymes in representative Chloroflexota, Firmicutes, Deinococcota and Verrucomicrobiota genomes. We identify a novel group of high-affinity [NiFe]-hydrogenases, group 1m, through phylogenetics, gene structure analysis and homology modeling, and reveal substantial genetic diversity within RuBisCO form IE (rbcL1E), and high-affinity 1h and 1l [NiFe]-hydrogenase groups. We conclude that atmospheric chemosynthesis is a globally-distributed phenomenon, extending throughout cold deserts, with significant implications for the global carbon cycle and bacterial survival within environmental reservoirs.

Characterization of Humic Acids Isolated from Selected Soils of Livingston Island by CP/MAS 13C NMR and ESR Spectroscopy

The tundra and tundra barrens of the maritime Antarctica represent a unique type of terrestrial ecosystem, geographically confined to the region of the Antarctic Peninsula and a number of surrounding archipelagos. Antarctic soils are underestimated in the quantity of organic matter (OM) pools, organic remnant humification/mineralization rates, and biogenic-abiogenic interactions. The structure of reserves for humic substances within the permafrost zone, as well as the role of the molecular composition of organic substances, are still poorly understood. In this study, we investigate humic acids of selected sub-Antarctic soils in terms of elemental and structural composition to evaluate OM stabilization degree and to assess carbon distributions in the molecules by solid-state CP/MAS 13C NMR and ESR spectroscopy. The results obtained show that the studied humic acids consist mainly of aliphatic structural fragments. According to ESR spectroscopy, it was noted that the most stable molecules by the data of ESR spectroscopy are formed in postornithogenic soils. In contrast, the average portion of the aromatic compounds is about 30% in humic acids, extracted from soils with evident ornithogenic effect.

Cyclic heptapeptides with metal binding properties isolated from the fungus Cadophora malorum from Antarctic soil

The Antarctic fungus Cadophora malorum produces previously undescribed cyclic heptapeptides (cadophorin A and B) containing an anthranilic acid residue. The planar structure of these peptides was determined by high-resolution mass spectrometry combined with extensive 1D and 2D NMR spectroscopy. The absolute configuration of the amino acids was determined by Marfey’s method, with HPLC analysis of FDVA (Nα-(2,4-dinitro-5-fluorphenyl)-l-valinamide) derivatives making use of a PFP column. Remarkably, cadophorin 2 possesses both the uncommon d-Ile and d-allo-Ile in its structure. The peptides have metal binding properties as shown by LCMS with post column addition of metal salt solutions. These results were supported by DFT calculations.Graphical

The intricate molecular identification of Streptomyces: a case study on Antarctic soil isolates.

Despite the worldwide use of 16S rRNA to identify bacterial species, the use of this gene does not discriminate the 750 species in the genus Streptomyces. A MLST scheme was constructed with rpoB, gyrB, recA, trpB and atpD genes to access the genomic variances in Streptomyces species evolution. We analyze the housekeeping genes in 49 Streptomyces isolates from Antarctic soil. It was used two different databases, GenBank and EzBioCloud to compare the 16S sequences. The species founded in both databases are not the same, but in both cases, a few isolates achieve the necessary high percentage to consider the identification. There is a lack of deposited sequences in the other genes, as the data in GenBank proved to be insufficient. Isolate LMA323St_9 has the potential to be studied as a novel species. Besides that, the use of housekeeping genes gives robust phylogenetic information to understand in group relationships.

The biotechnological potential of microbial communities from Antarctic soils and sediments: Application to low temperature biogenic methane production

Anaerobic digestion (AD) is an attractive bioprocess for waste treatment and energy recovery through methane-rich biogas production. Under temperate to cold climate, the implementation of AD for low-organic load wastewater treatment has been limited to date, due to the energetic and economic cost of maintaining optimal mesophilic temperature. Hence, we aim at (i) exploring the biotechnological potential of a microbial inoculum from Antarctic soils and sediments to run AD at low temperatures; and (ii) evaluating the effect of temperature over a psychrophilic-mesophilic range on both methane production rates and microbial community composition. Methane production stimulated by acetate amendment was detected from 5 to 37 °C, with a maximum at 25 °C, corresponding to the highest relative abundance of methanogenic archaea (c. 21.4% of the total community). From 5 to 25 °C, the predominant methanogen was Methanosaeta, while it shifted to Methanocorpusculum at 30 °C. Compared with an industrial mesophilic sludge, the relative methane production rate at 5 °C (compared to the maximum) was 40% greater in the Antarctic inoculum. Microbial communities from permanently cold Antarctic sediments efficiently produce methane at low temperatures revealing a biotechnological potential for the treatment of low-organic load residues in cold regions.

Biodegradation of Naphthalene and Anthracene by Aspergillus glaucus Strain Isolated from Antarctic Soil

Biotechnologies based on microbial species capable of destroying harmful pollutants are a successful way to solve some of the most important problems associated with a clean environment. The subject of investigation is the Antarctic fungal strain Aspergillus glaucus AL1. The culturing of the examined strain was performed with 70 mg of wet mycelium being inoculated in a Czapek Dox liquid medium containing naphthalene, anthracene, or phenanthrene (0.3 g/L) as the sole carbon source. Progressively decreasing naphthalene and anthracene concentrations were monitored in the culture medium until the 15th day of the cultivation of A. glaucus AL1. The degradation was determined through gas chromatography–mass spectrometry. Both decreased by 66% and 44%, respectively, for this period. The GC-MS analyses were applied to identify salicylic acid, catechol, and ketoadipic acid as intermediates in the naphthalene degradation. The intermediates identified in anthracene catabolism are 2-hydroxy-1-naphthoic acid, o-phthalic acid, and protocatechuic acid. The enzyme activities for phenol 2-monooxygenase (1.14.13.7) and catechol 1,2-dioxygenase (1.13.11.1) were established. A gene encoding an enzyme with catechol 1,2-dioxygenase activity was identified and sequenced (GeneBank Ac. No KM360483). The recent study provides original data on the potential of an ascomycete’s fungal strain A. glaucus strain AL 1 to degrade naphthalene and anthracene.

Atmospheric CCl4 degradation in Antarctic tundra soils and the evaluation on its partial atmospheric lifetime with respect to soil

Carbon tetrachloride (CCl4) is an anthropogenic gas with a long atmospheric lifetime and can catalyze the destruction of stratospheric ozone. Natural soils are believed to be important and widespread sinks of atmospheric CCl4, although poorly characterized due to a limited number of measurements. In this study, for the first time in situ static-chamber measurements and laboratory-based incubations for CCl4 fluxes were conducted at coastal Antarctic tundra. Results showed that soil in remote Antarctica is also acting as a CCl4 sink, with an average uptake rate of −2.2 ± 0.6 nmol m−2 d−1, which is comparable to the reported soil sinks in other regions of the world. No significant difference (p > 0.05) was found across different types of tundra, such normal upland tundra, coastal marsh tundra, and tundra in the sea animal colonies. Soil CCl4 fluxes did not show significant correlations (p > 0.05) with soil moisture, pH, TOC, TN, TP and Cl contents. Laboratory-based anoxic incubations showed that the uptake rates of CCl4 in tundra soil were suppressed; post-thermal sterilization incubations showed that soil CCl4 sink was enhanced; these results suggested that CCl4 degradation in tundra soil was likely an abiotic process preferring oxic environments. A rough extrapolation suggested that Antarctic tundra may degrade about 2.4 metric tons of atmospheric CCl4 each year. Combining soil CCl4 fluxes from this study and other literature reports, CCl4 partial lifetime with respect to the soil sink was evaluated to be 354 (235–474) years, which supported the recent viewpoint that the soil sink of CCl4 is smaller than previously thought.

Isolated indigenous yeasts from Antarctica with the ability to remove toxic hexavalent chromium

ABSTRACT Seven chromate-reducing yeasts isolated from Antarctic soils (with no history of Cr(VI) contamination) were evaluated as promising candidates for alleviating Cr(VI)-contamination. These yeast species have not been extensively studied regarding Cr(VI) tolerance and reduction abilities. Based on their tolerance (up to 2 mM) and ability to remove Cr(VI) from culture media, two representative isolates of Candida sake #14 and Debaryomyces hansenii #35 were chosen. The resistant yeasts were cultivated in YM medium plus 1 mM Cr(VI) at 25°C, causing a removal of ∼90 and ∼70% hexavalent chromium before reaching 96 h of culture according to growth curves of C. sake #14 and D. hansenii #35, respectively. Cr(VI) removal kinetic analysis indicated that both isolates removed Cr(VI) by reduction to Cr(III), and incorporated a small portion into the biomass. Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX) confirms the biosorption process, indicating the existence of a complex remediation mechanism. In conclusion, Antarctica is an extreme environment with a potential to discover promising new candidates for the removal of Cr(VI). These results are interesting from a biotechnological point of view since psychrotolerant yeasts could be involved in the design of a profitable technology for the elimination of the toxic form of Cr.

Microbial oxidation of atmospheric trace gases.

The atmosphere has recently been recognized as a major source of energy sustaining life. Diverse aerobic bacteria oxidize the three most abundant reduced trace gases in the atmosphere, namely hydrogen (H2), carbon monoxide (CO) and methane (CH4). This Review describes the taxonomic distribution, physiological role and biochemical basis of microbial oxidation of these atmospheric trace gases, as well as the ecological, environmental, medical and astrobiological importance of this process. Most soil bacteria and some archaea can survive by using atmospheric H2 and CO as alternative energy sources, as illustrated through genetic studies on Mycobacterium cells and Streptomyces spores. Certain specialist bacteria can also grow on air alone, as confirmed by the landmark characterization of Methylocapsa gorgona, which grows by simultaneously consuming atmospheric CH4, H2 and CO. Bacteria use high-affinity lineages of metalloenzymes, namely hydrogenases, CO dehydrogenases and methane monooxygenases, to utilize atmospheric trace gases for aerobic respiration and carbon fixation. More broadly, trace gas oxidizers enhance the biodiversity and resilience of soil and marine ecosystems, drive primary productivity in extreme environments such as Antarctic desert soils and perform critical regulatory services by mitigating anthropogenic emissions of greenhouse gases and toxic pollutants.

Arthrobacter terrae sp. nov., a psychrophilic actinobacterium with multi copies of capA gene isolated from Antarctic soil.

A Gram-staining-positive, non-spore-forming, non-flagellated, ellipsoidal, strain Z1-20T belonging to the genus Arthrobacter was isolated from a soil sample collected from the Zhongshan station, Antarctic. Phylogenetic analysis of the 16S rRNA gene sequences and phylogenetic analysis revealed that strain Z1-20T formed a unique single cluster in the genus Arthrobacter and shared high 16S rRNA sequence similarities of 97.1% and 96.9% with A. glacialis HLT2-12-2T and A. psychrochitiniphilus GP3T, respectively. Values of Digital DNA-DNA hybridization (dDDH) between strain Z1-20T against A. glacialis HLT2-12-2T and A. psychrochitiniphilus GP3T were 20.3% and 13.8%, respectively. Average nucleotide identity (ANI) score between strain Z1-20T against A. glacialis HLT2-12-2T and A. psychrochitiniphilus GP3T were 72.5% and 72.1%, respectively. Genes for the synthesis of the osmoprotectant glycine betaine and higher copies of capA gene encoding cold shock protein were found in genome of Z1-20T that may help Z1-20T in cold-adaptation. Strain Z1-20T comprised lysine as the diagnostic diamino acid. Based on the results of phylogenetic, phenotypic and chemotaxonomic features, strain Z1-20T represents a novel species of a novel taxon of genus Arthrobacter, for which the name Arthrobacter terrae gen. nov., sp. nov. is proposed.