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1.
Environ Microbiol ; 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33621409

RESUMO

Concurrent osmotic and chaotropic stress make MgCl2 -rich brines extremely inhospitable environments. Understanding the limits of life in these brines is essential to the search for extraterrestrial life on contemporary and relict ocean worlds, like Mars, which could host similar environments. We sequenced environmental 16S rRNA genes and quantified microbial activity across a broad range of salinity and chaotropicity at a Mars-analogue salt harvesting facility in Southern California, where seawater is evaporated in a series of ponds ranging from kosmotropic NaCl brines to highly chaotropic MgCl2 brines. Within NaCl brines, we observed a proliferation of specialized halophilic Euryarchaeota, which corresponded closely with the dominant taxa found in salterns around the world. These communities were characterized by very slow growth rates and high biomass accumulation. As salinity and chaotropicity increased, we found that the MgCl2 -rich brines eventually exceeded the limits of microbial activity. We found evidence that exogenous genetic material is preserved in these chaotropic brines, producing an unexpected increase in diversity in the presumably sterile MgCl2 -saturated brines. Because of their high potential for biomarker preservation, chaotropic brines could therefore serve as repositories of genetic biomarkers from nearby environments (both on Earth and beyond) making them prime targets for future life-detection missions.

2.
Annu Rev Biophys ; 50: 343-372, 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33637008

RESUMO

Sampling and genomic efforts over the past decade have revealed an enormous quantity and diversity of life in Earth's extreme environments. This new knowledge of life on Earth poses the challenge of understandingits molecular basis in such inhospitable conditions, given that such conditions lead to loss of structure and of function in biomolecules from mesophiles. In this review, we discuss the physicochemical properties of extreme environments. We present the state of recent progress in extreme environmental genomics. We then present an overview of our current understanding of the biomolecular adaptation to extreme conditions. As our current and future understanding of biomolecular structure-function relationships in extremophiles requires methodologies adapted to extremes of pressure, temperature, and chemical composition, advances in instrumentation for probing biophysical properties under extreme conditions are presented. Finally, we briefly discuss possible future directions in extreme biophysics.

3.
Environ Microbiol ; 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33538392

RESUMO

Deep-sea hypersaline anoxic basins (DHABs) are uniquely stratified polyextreme environments generally found in enclosed seas. These environments select for elusive and widely uncharacterized microbes that may be living below the currently recognized window of life on Earth. Still, there is strong evidence of highly specialized active microbial communities in the Kryos, Discovery, and Hephaestus basins located in the Eastern Mediterranean Sea; the only known athalassohaline DHABs. Life is further constrained in these DHABs as near-saturated concentrations of magnesium chloride significantly reduces water activity (aw ) and exerts extreme chaotropic stress, the tendency of a solution to disorder biomolecules. In this review, we provide an overview of microbial adaptations to polyextremes focusing primarily on chaotropicity, summarize current evidence of microbial life within athalassohaline DHABs and describe the difficulties of life detection approaches and sampling within these environments. We also reveal inconsistent measurements of chaotropic activity in the literature highlighting the need for a new methodology. Finally, we generate recommendations for future investigations and discuss the importance of athalassohaline DHAB research to help inform extraterrestrial life detection missions.

4.
BMC Genomics ; 21(1): 692, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33023469

RESUMO

BACKGROUND: The deep ocean is characterized by low temperatures, high hydrostatic pressures, and low concentrations of organic matter. While these conditions likely select for distinct genomic characteristics within prokaryotes, the attributes facilitating adaptation to the deep ocean are relatively unexplored. In this study, we compared the genomes of seven strains within the genus Colwellia, including some of the most piezophilic microbes known, to identify genomic features that enable life in the deep sea. RESULTS: Significant differences were found to exist between piezophilic and non-piezophilic strains of Colwellia. Piezophilic Colwellia have a more basic and hydrophobic proteome. The piezophilic abyssal and hadal isolates have more genes involved in replication/recombination/repair, cell wall/membrane biogenesis, and cell motility. The characteristics of respiration, pilus generation, and membrane fluidity adjustment vary between the strains, with operons for a nuo dehydrogenase and a tad pilus only present in the piezophiles. In contrast, the piezosensitive members are unique in having the capacity for dissimilatory nitrite and TMAO reduction. A number of genes exist only within deep-sea adapted species, such as those encoding d-alanine-d-alanine ligase for peptidoglycan formation, alanine dehydrogenase for NADH/NAD+ homeostasis, and a SAM methyltransferase for tRNA modification. Many of these piezophile-specific genes are in variable regions of the genome near genomic islands, transposases, and toxin-antitoxin systems. CONCLUSIONS: We identified a number of adaptations that may facilitate deep-sea radiation in members of the genus Colwellia, as well as in other piezophilic bacteria. An enrichment in more basic and hydrophobic amino acids could help piezophiles stabilize and limit water intrusion into proteins as a result of high pressure. Variations in genes associated with the membrane, including those involved in unsaturated fatty acid production and respiration, indicate that membrane-based adaptations are critical for coping with high pressure. The presence of many piezophile-specific genes near genomic islands highlights that adaptation to the deep ocean may be facilitated by horizontal gene transfer through transposases or other mobile elements. Some of these genes are amenable to further study in genetically tractable piezophilic and piezotolerant deep-sea microorganisms.

5.
Microb Ecol ; 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32995929

RESUMO

Piezophiles, by the commonly accepted definition, grow faster under high hydrostatic pressure (HHP) than under ambient pressure and are believed to exist only in pressurized environments where life has adapted to HHP during evolution. However, recent findings suggest that piezophiles have developed a common adaptation strategy to cope with multiple types of stresses including HHP. These results raise a question on the ecological niches of piezophiles: are piezophiles restricted to habitats with HHP? In this study, we observed that the bacterial strains Sporosarcina psychrophila DSM 6497 and Lysinibacillus sphaericus LMG 22257, which were isolated from surface environments and then transferred under ambient pressure for half a century, possess moderately piezophilic characteristics with optimal growth pressures of 7 and 20 MPa, respectively. Their tolerance to HHP was further enhanced by MgCl2 supplementation under the highest tested pressure of 50 MPa. Transcriptomic analysis was performed to compare gene expression with and without MgCl2 supplementation under 50 MPa for S. psychrophila DSM 6497. Among 4390 genes or transcripts obtained, 915 differentially expressed genes (DEGs) were identified. These DEGs are primarily associated with the antioxidant defense system, intracellular compatible solute accumulation, and membrane lipid biosynthesis, which have been reported to be essential for cells to cope with HHP. These findings indicate no in situ pressure barrier for piezophile isolation, and cells may adopt a common adaptation strategy to cope with different stresses.

6.
Environ Microbiol ; 22(5): 1829-1846, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31840312

RESUMO

Anaerobic methanotrophic archaea (ANME) consume methane in marine sediments, limiting its release to the water column, but their responses to changes in methane and sulfate supplies remain poorly constrained. To address how methane exposure may affect microbial communities and methane- and sulfur-cycling gene abundances in Arctic marine sediments, we collected sediments from offshore Svalbard that represent geochemical horizons where anaerobic methanotrophy is expected to be active, previously active, and long-inactive based on reaction-transport biogeochemical modelling of porewater sulfate profiles. Sediment slurries were incubated at in situ temperature and pressure with different added methane concentrations. Sediments from an active area of seepage began to reduce sulfate in a methane-dependent manner within months, preceding increased relative abundances of anaerobic methanotrophs ANME-1 within communities. In previously active and long-inactive sediments, sulfur-cycling Deltaproteobacteria became more dominant after 30 days, though these communities showed no evidence of methanotrophy after nearly 8 months of enrichment. Overall, enrichment conditions, but not methane, broadly altered microbial community structure across different enrichment times and sediment types. These results suggest that active ANME populations may require years to develop, and consequently microbial community composition may affect methanotrophic responses to potential large-scale seafloor methane releases in ways that provide insight for future modelling studies.

7.
ISME J ; 13(12): 3067-3079, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31462715

RESUMO

Thaumarchaeota are responsible for a significant fraction of ammonia oxidation in the oceans and in soils that range from alkaline to acidic. However, the adaptive mechanisms underpinning their habitat expansion remain poorly understood. Here we show that expansion into acidic soils and the high pressures of the hadopelagic zone of the oceans is tightly linked to the acquisition of a variant of the energy-yielding ATPases via horizontal transfer. Whereas the ATPase genealogy of neutrophilic Thaumarchaeota is congruent with their organismal genealogy inferred from concatenated conserved proteins, a common clade of V-type ATPases unites phylogenetically distinct clades of acidophilic/acid-tolerant and piezophilic/piezotolerant species. A presumptive function of pumping cytoplasmic protons at low pH is consistent with the experimentally observed increased expression of the V-ATPase in an acid-tolerant thaumarchaeote at low pH. Consistently, heterologous expression of the thaumarchaeotal V-ATPase significantly increased the growth rate of E. coli at low pH. Its adaptive significance to growth in ocean trenches may relate to pressure-related changes in membrane structure in which this complex molecular machine must function. Together, our findings reveal that the habitat expansion of Thaumarchaeota is tightly correlated with extensive horizontal transfer of atp operons.


Assuntos
Adenosina Trifosfatases/genética , Archaea/genética , Proteínas Arqueais/genética , Transferência Genética Horizontal , Óperon , Adenosina Trifosfatases/metabolismo , Compostos de Amônio/metabolismo , Archaea/classificação , Archaea/enzimologia , Archaea/isolamento & purificação , Proteínas Arqueais/metabolismo , Ecossistema , Escherichia coli/metabolismo , Concentração de Íons de Hidrogênio , Oxirredução , Filogenia , Microbiologia do Solo
8.
Extremophiles ; 23(4): 421-433, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31049708

RESUMO

The deep biosphere is often characterized by multiple extreme physical-chemical conditions, of which pressure is an important parameter that influences life but remains less studied. This geomicrobiology study was designed to understand the response of a subterranean microbial community of the Deccan traps to high-pressure conditions and to elucidate their genomic properties. Groundwater from a deep basaltic aquifer of the Deccan traps was used to ascertain the community response to 25 MPa and 50 MPa pressure following enrichment in high-salt and low-salt organic media. Quantitative PCR data indicated a decrease in bacterial and archaeal cell numbers with increasing pressure. 16S rRNA gene sequencing displayed substantial changes in the microbial community in which Acidovorax appeared to be the most dominant genus in the low-salt medium and Microbacteriaceae emerged as the major family in the high-salt medium under both pressure conditions. Genes present in metagenome-associated genomes which have previously been associated with piezotolerance include those related to nutrient uptake and extracytoplasmic stress (omp, rseC), protein folding and unfolding (dnaK, groEL and others), and DNA repair mechanisms (mutT, uvr and others). We hypothesize that these genes facilitate tolerance to high pressure by certain groups of microbes residing in subsurface Deccan traps.


Assuntos
Água Subterrânea/microbiologia , Pressão Hidrostática , Metagenoma , Microbiota , Tolerância ao Sal , Comamonadaceae/isolamento & purificação , Genes Arqueais , Genes Bacterianos
9.
Front Microbiol ; 10: 347, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30930856

RESUMO

Hadal ocean sediments, found at sites deeper than 6,000 m water depth, are thought to contain microbial communities distinct from those at shallower depths due to high hydrostatic pressures and higher abundances of organic matter. These communities may also differ from one other as a result of geographical isolation. Here we compare microbial community composition in surficial sediments of two hadal environments-the Mariana and Kermadec trenches-to evaluate microbial biogeography at hadal depths. Sediment microbial consortia were distinct between trenches, with higher relative sequence abundances of taxa previously correlated with organic matter degradation present in the Kermadec Trench. In contrast, the Mariana Trench, and deeper sediments in both trenches, were enriched in taxa predicted to break down recalcitrant material and contained other uncharacterized lineages. At the 97% similarity level, sequence-abundant taxa were not trench-specific and were related to those found in other hadal and abyssal habitats, indicating potential connectivity between geographically isolated sediments. Despite the diversity of microorganisms identified using culture-independent techniques, most isolates obtained under in situ pressures were related to previously identified piezophiles. Members related to these same taxa also became dominant community members when native sediments were incubated under static, long-term, unamended high-pressure conditions. Our results support the hypothesis that there is connectivity between sediment microbial populations inhabiting the Mariana and Kermadec trenches while showing that both whole communities and specific microbial lineages vary between trench of collection and sediment horizon depth. This in situ biodiversity is largely missed when incubating samples within pressure vessels and highlights the need for revised protocols for high-pressure incubations.

10.
Artigo em Inglês | MEDLINE | ID: mdl-30533830

RESUMO

Metagenomic sequencing of fracture fluid from South Africa recovered a nearly complete "Candidatus Bathyarchaeota" archaeon genome. The metagenome-assembled genome of BE326-BA-RLH contains genes involved in methane metabolism and dissimilatory nitrate reduction. This study presents the first genomic evidence for potential anaerobic methane oxidation in the phylum "Ca. Bathyarchaeota."

12.
Front Microbiol ; 9: 808, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29755436

RESUMO

The Deepwater Horizon oil spill was one of the largest and deepest oil spills recorded. The wellhead was located at approximately 1500 m below the sea where low temperature and high pressure are key environmental characteristics. Using cells collected 4 months following the Deepwater Horizon oil spill at the Gulf of Mexico, we set up Macondo crude oil enrichments at wellhead temperature and different pressures to determine the effect of increasing depth/pressure to the in situ microbial community and their ability to degrade oil. We observed oil degradation under all pressure conditions tested [0.1, 15, and 30 megapascals (MPa)], although oil degradation profiles, cell numbers, and hydrocarbon degradation gene abundances indicated greatest activity at atmospheric pressure. Under all incubations the growth of psychrophilic bacteria was promoted. Bacteria closely related to Oleispira antarctica RB-8 dominated the communities at all pressures. At 30 MPa we observed a shift toward Photobacterium, a genus that includes piezophiles. Alphaproteobacterial members of the Sulfitobacter, previously associated with oil-degradation, were also highly abundant at 0.1 MPa. Our results suggest that pressure acts synergistically with low temperature to slow microbial growth and thus oil degradation in deep-sea environments.

13.
PLoS One ; 13(4): e0195102, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29621268

RESUMO

Hadal trenches, oceanic locations deeper than 6,000 m, are thought to have distinct microbial communities compared to those at shallower depths due to high hydrostatic pressures, topographical funneling of organic matter, and biogeographical isolation. Here we evaluate the hypothesis that hadal trenches contain unique microbial biodiversity through analyses of the communities present in the bottom waters of the Kermadec and Mariana trenches. Estimates of microbial protein production indicate active populations under in situ hydrostatic pressures and increasing adaptation to pressure with depth. Depth, trench of collection, and size fraction are important drivers of microbial community structure. Many putative hadal bathytypes, such as members related to the Marinimicrobia, Rhodobacteraceae, Rhodospirilliceae, and Aquibacter, are similar to members identified in other trenches. Most of the differences between the two trench microbiomes consists of taxa belonging to the Gammaproteobacteria whose distributions extend throughout the water column. Growth and survival estimates of representative isolates of these taxa under deep-sea conditions suggest that some members may descend from shallower depths and exist as a potentially inactive fraction of the hadal zone. We conclude that the distinct pelagic communities residing in these two trenches, and perhaps by extension other trenches, reflect both cosmopolitan hadal bathytypes and ubiquitous genera found throughout the water column.


Assuntos
Sedimentos Geológicos/microbiologia , Microbiota , Oceanos e Mares , Microbiologia da Água , Adaptação Biológica , Biodiversidade , Pressão Hidrostática , Metagenoma , Metagenômica/métodos
14.
Microb Biotechnol ; 10(6): 1454-1456, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29027382
15.
Environ Microbiol ; 19(7): 2769-2784, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28474498

RESUMO

Candidate phyla (CP) are broad phylogenetic clusters of organisms that lack cultured representatives. Included in this fraction is the candidate Parcubacteria superphylum. Specific characteristics that have been ascribed to the Parcubacteria include reduced genome size, limited metabolic potential and exclusive reliance on fermentation for energy acquisition. The study of new environmental niches, such as the marine versus terrestrial subsurface, often expands the understanding of the genetic potential of taxonomic groups. For this reason, we analyzed 12 Parcubacteria single amplified genomes (SAGs) from sediment samples collected within the Challenger Deep of the Mariana Trench, obtained during the Deepsea Challenge (DSC) Expedition. Many of these SAGs are closely related to environmental sequences obtained from deep-sea environments based on 16S rRNA gene similarity and BLAST matches to predicted proteins. DSC SAGs encode features not previously identified in Parcubacteria obtained from other habitats. These include adaptation to oxidative stress, polysaccharide modification and genes associated with respiratory nitrate reduction. The DSC SAGs are also distinguished by relative greater abundance of genes for nucleotide and amino acid biosynthesis, repair of alkylated DNA and the synthesis of mechanosensitive ion channels. These results present an expanded view of the Parcubacteria, among members residing in an ultra-deep hadal environment.


Assuntos
Bactérias/genética , Genoma Bacteriano/genética , Sedimentos Geológicos/microbiologia , Análise de Célula Única/métodos , Aminoácidos/biossíntese , Bactérias/metabolismo , Reparo do DNA/genética , Ecossistema , Meio Ambiente , Tamanho do Genoma/genética , Nitrato Redutases/genética , Nitratos/metabolismo , Oceanos e Mares , Filogenia , Polissacarídeos/metabolismo , RNA Ribossômico 16S/genética
16.
Mol Ecol ; 26(14): 3732-3743, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28429829

RESUMO

The Challenger Deep in the Mariana Trench is the deepest point in the oceans of our planet. Understanding how animals adapt to this harsh environment characterized by high hydrostatic pressure, food limitation, dark and cold is of great scientific interest. Of the animals dwelling in the Challenger Deep, amphipods have been captured using baited traps. In this study, we sequenced the transcriptome of the amphipod Hirondellea gigas collected at a depth of 10,929 m from the East Pond of the Challenger Deep. Assembly of these sequences resulted in 133,041 contigs and 22,046 translated proteins. Functional annotation of these contigs was made using the go and kegg databases. Comparison of these translated proteins with those of four shallow-water amphipods revealed 10,731 gene families, of which 5659 were single-copy orthologs. Base substitution analysis on these single-copy orthologs showed that 62 genes are positively selected in H. gigas, including genes related to ß-alanine biosynthesis, energy metabolism and genetic information processing. For multiple-copy orthologous genes, gene family expansion analysis revealed that cold-inducible proteins (i.e., transcription factors II A and transcription elongation factor 1) as well as zinc finger domains are expanded in H. gigas. Overall, our results indicate that genetic adaptation to the hadal environment by H. gigas may be mediated by both gene family expansion and amino acid substitutions of specific proteins.


Assuntos
Adaptação Fisiológica/genética , Anfípodes/genética , Transcriptoma , Substituição de Aminoácidos , Animais , Meio Ambiente , Família Multigênica , Oceanos e Mares
17.
Int J Syst Evol Microbiol ; 67(4): 824-831, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27902293

RESUMO

An obligately piezophilic strain was isolated from an amphipod crustacean obtained in the Challenger Deep region of the Mariana Trench during the DEEPSEA CHALLENGE expedition. The strain, MTCD1T, grew at extremely high hydrostatic pressures, with a growth range of 80-140 MPa (optimum, 120 MPa) at 6 °C. Phylogenetic analyses based on the 16S rRNA gene sequence indicate that it is closely affiliated with the genus Colwellia. Comparative 16S rRNA gene sequence analyses revealed 95.7, 95.5 and 95.2 % similarity to Colwellia maris ABE-1T, Colwellia piezophila Y233GT and Colwellia psychrerythraea ATCC 27364T, respectively. The major cellular fatty acids were C16 : 1, C16 : 0 and C22 : 6 (docosahexaenoic acid), and the sole isoprenoid quinone produced was ubiqinone-8. DNA G+C content was 48.6 mol%. The strain was positive for oxidase and catalase activities. Based on the results from this study, strain MTCD1T is a novel Gram-negative species of the genus Colwellia, and the name Colwellia marinimaniae sp. nov. (type strain MTCD1T=ATCC TSD-5T=JCM 30270T) is proposed. It is the most piezophilic organism yet described.


Assuntos
Alteromonadaceae/classificação , Anfípodes/microbiologia , Filogenia , Alteromonadaceae/genética , Alteromonadaceae/isolamento & purificação , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , DNA Ribossômico/genética , Ácidos Graxos/química , Pressão Hidrostática , Hibridização de Ácido Nucleico , Oceano Pacífico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
18.
Front Microbiol ; 7: 665, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27242695

RESUMO

Relatively few studies have described the microbial populations present in ultra-deep hadal environments, largely as a result of difficulties associated with sampling. Here we report Illumina-tag V6 16S rRNA sequence-based analyses of the free-living and particle-associated microbial communities recovered from locations within two of the deepest hadal sites on Earth, the Challenger Deep (10,918 meters below surface-mbs) and the Sirena Deep (10,667 mbs) within the Mariana Trench, as well as one control site (Ulithi Atoll, 761 mbs). Seawater samples were collected using an autonomous lander positioned ~1 m above the seafloor. The bacterial populations within the Mariana Trench bottom water samples were dissimilar to other deep-sea microbial communities, though with overlap with those of diffuse flow hydrothermal vents and deep-subsurface locations. Distinct particle-associated and free-living bacterial communities were found to exist. The hadal bacterial populations were also markedly different from one another, indicating the likelihood of different chemical conditions at the two sites. In contrast to the bacteria, the hadal archaeal communities were more similar to other less deep datasets and to each other due to an abundance of cosmopolitan deep-sea taxa. The hadal communities were enriched in 34 bacterial and 4 archaeal operational taxonomic units (OTUs) including members of the Gammaproteobacteria, Epsilonproteobacteria, Marinimicrobia, Cyanobacteria, Deltaproteobacteria, Gemmatimonadetes, Atribacteria, Spirochaetes, and Euryarchaeota. Sequences matching cultivated piezophiles were notably enriched in the Challenger Deep, especially within the particle-associated fraction, and were found in higher abundances than in other hadal studies, where they were either far less prevalent or missing. Our results indicate the importance of heterotrophy, sulfur-cycling, and methane and hydrogen utilization within the bottom waters of the deeper regions of the Mariana Trench, and highlight novel community features of these extreme habitats.

19.
Appl Environ Microbiol ; 81(24): 8265-76, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26386059

RESUMO

Hadal ecosystems are found at a depth of 6,000 m below sea level and below, occupying less than 1% of the total area of the ocean. The microbial communities and metabolic potential in these ecosystems are largely uncharacterized. Here, we present four single amplified genomes (SAGs) obtained from 8,219 m below the sea surface within the hadal ecosystem of the Puerto Rico Trench (PRT). These SAGs are derived from members of deep-sea clades, including the Thaumarchaeota and SAR11 clade, and two are related to previously isolated piezophilic (high-pressure-adapted) microorganisms. In order to identify genes that might play a role in adaptation to deep-sea environments, comparative analyses were performed with genomes from closely related shallow-water microbes. The archaeal SAG possesses genes associated with mixotrophy, including lipoylation and the glycine cleavage pathway. The SAR11 SAG encodes glycolytic enzymes previously reported to be missing from this abundant and cosmopolitan group. The other SAGs, which are related to piezophilic isolates, possess genes that may supplement energy demands through the oxidation of hydrogen or the reduction of nitrous oxide. We found evidence for potential trench-specific gene distributions, as several SAG genes were observed only in a PRT metagenome and not in shallower deep-sea metagenomes. These results illustrate new ecotype features that might perform important roles in the adaptation of microorganisms to life in hadal environments.


Assuntos
Archaea/classificação , Archaea/genética , Genoma Arqueal/genética , Metagenoma/genética , Água do Mar/microbiologia , Aclimatação , Archaea/isolamento & purificação , Sequência de Bases , DNA Arqueal/genética , Ecossistema , Metabolismo Energético/fisiologia , Ácidos Graxos/metabolismo , Lipídeos/biossíntese , Dados de Sequência Molecular , Oceanos e Mares , Porto Rico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Enxofre/metabolismo , Microbiologia da Água
20.
Curr Opin Biotechnol ; 33: 157-64, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25776196

RESUMO

A key aspect of marine environments is elevated pressure; for example, ∼70% of the ocean is at a pressure of at least 38MPa. Many types of Bacteria and Archaea reside under these high pressures, which drive oceanic biogeochemical cycles and catalyze reactions among rocks, sediments and fluids. Most marine prokaryotes are classified as piezotolerant or as (obligate)-piezophiles with few cultivated relatives. The biochemistry and physiology of these organisms are largely unknown. Recently, high-pressure cultivation technology has been combined with omics and DNA recombination methodologies to examine the physiology of piezophilic marine microorganisms. We are now beginning to understand the adaptive mechanisms of these organisms, along with their ecological functions and evolutionary processes. This knowledge is leading to the further development of high-pressure-based biotechnology.


Assuntos
Bactérias/genética , Biotecnologia , Adaptação Fisiológica , Animais , Archaea/genética , Biotecnologia/métodos , Engenharia Genética , Oceanos e Mares , Pressão
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