Draft Genome Sequence of
            <i>Williamsia</i>
            sp. Strain D3, Isolated From the Darwin Mountains, Antarctica

Guerrero, Leandro D.; Makhalanyane, Thulani P.; Aislabie, Jackie; Cowan, Don A.

doi:10.1128/genomea.01230-13

Cited by 10 publications

(8 citation statements)

References 10 publications

(9 reference statements)

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“…and Microbacterium sp.. Representatives of Williamsia are known to inhabit arid environments such as Antarctic desert soils (Guerrero et al, 2014 ) and have been previously isolated from BSCs (Gundlapally and Garcia-Pichel, 2006 ) as have Microbacterium sp. (Gundlapally and Garcia-Pichel, 2006 ).…”

Section: Discussionmentioning

confidence: 99%

Isolation of a significant fraction of non-phototroph diversity from a desert Biological Soil Crust

et al. 2015

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Biological Soil Crusts (BSCs) are organosedimentary assemblages comprised of microbes and minerals in topsoil of terrestrial environments. BSCs strongly impact soil quality in dryland ecosystems (e.g., soil structure and nutrient yields) due to pioneer species such as Microcoleus vaginatus; phototrophs that produce filaments that bind the soil together, and support an array of heterotrophic microorganisms. These microorganisms in turn contribute to soil stability and biogeochemistry of BSCs. Non-cyanobacterial populations of BSCs are less well known than cyanobacterial populations. Therefore, we attempted to isolate a broad range of numerically significant and phylogenetically representative BSC aerobic heterotrophs. Combining simple pre-treatments (hydration of BSCs under dark and light) and isolation strategies (media with varying nutrient availability and protection from oxidative stress) we recovered 402 bacterial and one fungal isolate in axenic culture, which comprised 116 phylotypes (at 97% 16S rRNA gene sequence homology), 115 bacterial and one fungal. Each medium enriched a mostly distinct subset of phylotypes, and cultivated phylotypes varied due to the BSC pre-treatment. The fraction of the total phylotype diversity isolated, weighted by relative abundance in the community, was determined by the overlap between isolate sequences and OTUs reconstructed from metagenome or metatranscriptome reads. Together, more than 8% of relative abundance of OTUs in the metagenome was represented by our isolates, a cultivation efficiency much larger than typically expected from most soils. We conclude that simple cultivation procedures combined with specific pre-treatment of samples afford a significant reduction in the culturability gap, enabling physiological and metabolic assays that rely on ecologically relevant axenic cultures.

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Section: Discussionmentioning

confidence: 99%

Isolation of a significant fraction of non-phototroph diversity from a desert Biological Soil Crust

et al. 2015

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“…There are currently no available cyanobacterial genomes from Arctic and Antarctic habitats, although we are aware of two draft genomes of isolates from Antarctic cyanobacterial mats Reddy et al 2013). Such genome data may be crucial in revealing mechanistic insights of polar cyanobacterial isolates as has been done very recently with other phyla Ferreras et al 2014;Guerrero et al 2014;Ronca et al 2015). There is also a general lack of publicly available cyanobacterial virome data, which may lead to poor representation and potential underestimation of cyanophages in Antarctic environments (Zablocki et al 2014).…”

Section: Discussionmentioning

confidence: 99%

Ecology and biogeochemistry of cyanobacteria in soils, permafrost, aquatic and cryptic polar habitats

et al. 2015

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Polar Regions (continental Antarctica and the Arctic) are characterized by a range of extreme environmental conditions, which impose severe pressures on biological life. Polar cold-active cyanobacteria are uniquely adapted to withstand the environmental conditions of the high latitudes. These adaptations include high ultra-violet radiation and desiccation tolerance, and mechanisms to protect cells from freeze-thaw damage. As the most widely distributed photoautotrophs in these regions, cyanobacteria are likely the dominant contributors of critically essential ecosystem services, particularly carbon and nitrogen turnover in terrestrial polar habitats. These habitats include soils, permafrost, cryptic niches (including biological soil crusts, hypoliths and endoliths), ice and snow, and a range of aquatic habitats. Here we review current literature on the ecology, and the functional role played by cyanobacteria in various Arctic and Antarctic environments. We focus on the ecological importance of cyanobacterial communities in Polar Regions and assess what is known regarding the toxins they produce. We also review the responses and adaptations of cyanobacteria to extreme environments.

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“…Recent draft genomes of Actinobacterial isolates from cold soil environments have provided some new insights into the metabolic adaptation of these bacteria to cold environments [32,33]. Actinobacteria are capable of maintaining metabolic activity and DNA repair processes [34] at low temperatures, critical adaptations to survival in polar soil habitats where the seasonal metabolic window is limited [7] and DNA damage from freeze-thaw, desiccation and associated oxidative processes and radiation damage is all thought to be one of the major impositions on survival [35].…”

Section: Microbial Diversity In Cold Environmentsmentioning

confidence: 99%

Microbial diversity and functional capacity in polar soils

Makhalanyane

Goethem

Cowan

2016

Current Opinion in Biotechnology

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Global change is disproportionately affecting cold environments (polar and high elevation regions), with potentially negative impacts on microbial diversity and functional processes. In most cold environments the combination of low temperatures, and physical stressors, such as katabatic wind episodes and limited water availability result in biotic systems, which are in trophic terms very simple and primarily driven by microbial communities. Metagenomic approaches have provided key insights on microbial communities in these systems and how they may adapt to stressors and contribute towards mediating crucial biogeochemical cycles. Here we review, the current knowledge regarding edaphic-based microbial diversity and functional processes in Antarctica, and the Artic. Such insights are crucial and help to establish a baseline for understanding the impact of climate change on Polar Regions. AddressCentre for Microbial Ecology and Genomics, Department of Genetics, University of Pretoria, Pretoria 0028, South Africa Corresponding author: Cowan, Don Arthur (don.cowan@up.ac.za) IntroductionThe Congress of Parties (COP) 21 meeting in Paris (November 2015) highlighted the urgency of global climate change, and the critical need to reduce global average temperatures through curbing greenhouse gas emissions [1]. Nowhere are the effects of global change more apparent than in cold environments (polar and alpine regions), which are subject to accelerated rates of warming compared to other ecosystems [2 ,3]. Climatic models have predicted that temperatures in high latitude regions of the Northern Hemisphere are likely to increase by between 0.38C and 4.88C before the end of the twenty first century [4]. There is also evidence that regions in the Southern Hemisphere have experienced the fastest warming globally, with average increases of as much as 2.48C in the last fifty years [5].A major consequence of climate change in cold environments is the thawing of submerged and surface ice, which alters the hydrology of the systems and may have adverse effects on microbial processes [6 ]. In cold environments, microorganisms (bacteria, archaea and fungi) are major constituents of the total biomass, and are estimated to mediate the cycling of key biogeochemical elements such as nitrogen and carbon, with potentially important implications for the productivity of these systems [7]. Although the precise contribution of microbial processes to global change processes are not well known, there are efforts to incorporate biological processes into Earth systems models with the realization that they may be crucial in regulating soil organic matter (SOM) [8 ]. For instance, permafrost (defined as ground which remains frozen for at least two years) in cold environments stores roughly 1600 Pg of carbon, which if released would significantly contribute towards increasing global CO 2 levels [9]. The current contribution of microbial communities to constraining carbon losses in permafrost and the influence on CO 2 levels remains virtually unknown. In ...

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Draft Genome Sequence of Williamsia sp. Strain D3, Isolated From the Darwin Mountains, Antarctica

Cited by 10 publications

References 10 publications

Isolation of a significant fraction of non-phototroph diversity from a desert Biological Soil Crust

Isolation of a significant fraction of non-phototroph diversity from a desert Biological Soil Crust

Ecology and biogeochemistry of cyanobacteria in soils, permafrost, aquatic and cryptic polar habitats

Microbial diversity and functional capacity in polar soils

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