scholarly journals Effects of High Hydrostatic Pressure on Coastal Bacterial Community Abundance and Diversity

2014 ◽  
Vol 80 (19) ◽  
pp. 5992-6003 ◽  
Author(s):  
Angeliki Marietou ◽  
Douglas H. Bartlett
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Surface Waters ◽  
Deep Sea ◽  
Sea Surface ◽  
Bacterial Populations ◽  
Content Type ◽  
Microbial Life ◽  
Community Changes ◽  
Abundance And Diversity

ABSTRACTHydrostatic pressure is an important parameter influencing the distribution of microbial life in the ocean. In this study, the response of marine bacterial populations from surface waters to pressures representative of those under deep-sea conditions was examined. Southern California coastal seawater collected 5 m below the sea surface was incubated in microcosms, using a range of temperatures (16 to 3°C) and hydrostatic pressure conditions (0.1 to 80 MPa). Cell abundance decreased in response to pressure, while diversity increased. The morphology of the community also changed with pressurization to a predominant morphotype of small cocci. The pressure-induced community changes included an increase in the relative abundance ofAlphaproteobacteria,Gammaproteobacteria,Actinobacteria, andFlavobacterialargely at the expense ofEpsilonproteobacteria. Culturable high-pressure-surviving bacteria were obtained and found to be phylogenetically similar to isolates from cold and/or deep-sea environments. These results provide novel insights into the response of surface water bacteria to changes in hydrostatic pressure.

Microbial Life in the Trenches

2009 ◽  
Vol 43 (5) ◽  
pp. 128-131 ◽  
Author(s):  
Douglas H. Bartlett
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Deep Sea ◽  
Ocean Engineering ◽  
Deep Trench ◽  
Microbial Life ◽  
Elevated Hydrostatic Pressure ◽  
Pure Cultures ◽  
History Of ◽  
Challenger Deep

AbstractMicrobiologists have been making use of advances in ocean engineering to explore life in deep-sea trenches for decades, including for many years preceding man’s conquest of the Challenger Deep. This has fostered the development of an unusual branch of microbiology, referred to as high-pressure microbiology. Evidence for deep-trench microbes that grow best at elevated hydrostatic pressure was first obtained in the early 1950s, and isolates were obtained in pure cultures beginning in the early 1980s. Here I describe some of the history of deep-trench microbiology and the characteristics of microbial life in the trenches.

scholarly journals FabF Is Required for Piezoregulation ofcis-Vaccenic Acid Levels and Piezophilic Growth of the Deep-Sea Bacterium Photobacterium profundum Strain SS9

2000 ◽  
Vol 182 (5) ◽  
pp. 1264-1271 ◽  
Author(s):  
Eric E. Allen ◽  
Douglas H. Bartlett
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Deep Sea ◽  
Unsaturated Fatty Acids ◽  
Acyl Carrier Protein ◽  
Vaccenic Acid ◽  
Bacterial Species ◽  
Elevated Pressure ◽  
Wild Type ◽  
Photobacterium Profundum

ABSTRACT To more fully explore the role of unsaturated fatty acids in high-pressure, low-temperature growth, the fabF gene from the psychrotolerant, piezophilic deep-sea bacteriumPhotobacterium profundum strain SS9 was characterized and its role and regulation were examined. An SS9 strain harboring a disruption in the fabF gene (strain EA40) displayed growth impairment at elevated hydrostatic pressure concomitant with diminishedcis-vaccenic acid (18:1) production. However, growth ability at elevated pressure could be restored to wild-type levels by the addition of exogenous 18:1 to the growth medium. Transcript analysis did not indicate that the SS9 fabF gene is transcriptionally regulated, suggesting that the elevated 18:1 levels produced in response to pressure increase result from posttranscriptional changes. Unlike many pressure-adapted bacterial species such as SS9, the mesophile Escherichia coli did not regulate its fatty acid composition in an adaptive manner in response to changes in hydrostatic pressure. Moreover, an E. coli fabF strain was as susceptible to elevated pressure as wild-type cells. It is proposed that the SS9 fabF product, β-ketoacyl–acyl carrier protein synthase II has evolved novel pressure-responsive characteristics which facilitate SS9 growth at high pressure.

scholarly journals Updated definitions on piezophily as suggested by hydrostatic pressure dependence on temperature

2020 ◽  
Author(s):  
Alberto Scoma
Keyword(s):  
Hydrostatic Pressure ◽  
Deep Sea ◽  
Ambient Pressure ◽  
Environmental Parameters ◽  
Microbial Life ◽  
Deep Waters ◽  
Microbial Response ◽  
Definition Of ◽  
Substrate Ph ◽  
Cell Functionality

AbstractMicrobial preference for elevated hydrostatic pressure (HP) is a recognized key feature of environmental and industrial processes. HP effects on macromolecules and, consequently, cell functionality has been accurately described in the last decades. While there is little debate about the importance of HP in shaping microbial life, a systematic definition of microbial preference for increased HP is missing. The lack of a consensus about ‘true’ piezophiles, and ‘low’ or ‘high’ HP levels, has deleterious repercussions on microbiology and biotechnology. As certain levels are considered ‘low’ they are not applied to assess microbial activity. Most microorganisms collected in deep waters or sediments have not been tested (nor isolated) using the corresponding HP at which they were captured. Microbial response to HP is notoriously dependent on other environmental parameters, most notably temperature, but also on availability of nutrients, growth substrate, pH and salinity. This implies that countless isolates retrieved from ambient pressure conditions may very well require increased HP to grow optimally, as already demonstrated in both Archaea and Bacteria.In the present study, I collected the data from described piezophilic isolates and used the fundamental correlation existing between HP and temperature, as first suggested in seminal works by Yayanos, to update the definition of piezophiles. Thanks to the numerous new piezophilic isolates available since such seminal studies, the present analysis brings forward updated definitions which concern 1) the actual beginning of the piezosphere, the area in the deep sea where piezophiles thrive; 2) the HP thresholds which should be considered low, medium and high HP, and their implications for experimental design in Microbiology; and 3) the nature of obligate piezophiles and their location in the deep sea.

scholarly journals Distinctive Microbial Community Structure in Highly Stratified Deep-Sea Brine Water Columns

2013 ◽  
Vol 79 (11) ◽  
pp. 3425-3437 ◽  
Author(s):  
S. Bougouffa ◽  
J. K. Yang ◽  
O. O. Lee ◽  
Y. Wang ◽  
Z. Batang ◽  
...  
Keyword(s):  
Deep Sea ◽  
Sea Water ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Bacterial Populations ◽  
Content Type ◽  
Deep Sea Water ◽  
Cell Counts ◽  
Red Sea Rift ◽  
Group I

ABSTRACTAtlantis II and Discovery are two hydrothermal and hypersaline deep-sea pools in the Red Sea rift that are characterized by strong thermohalo-stratification and temperatures steadily peaking near the bottom. We conducted comprehensive vertical profiling of the microbial populations in both pools and highlighted the influential environmental factors. Pyrosequencing of the 16S rRNA genes revealed shifts in community structures vis-à-vis depth. High diversity and low abundance were features of the deepest convective layers despite the low cell density. Surprisingly, the brine interfaces had significantly higher cell counts than the overlying deep-sea water, yet they were lowest in diversity. Vertical stratification of the bacterial populations was apparent as we moved from theAlphaproteobacteria-dominated deep sea to thePlanctomycetaceae- orDeferribacteres-dominated interfaces to theGammaproteobacteria-dominated brine layers. Archaeal marine group I was dominant in the deep-sea water and interfaces, while several euryarchaeotic groups increased in the brine. Across sites, microbial phylotypes and abundances varied substantially in the brine interface of Discovery compared with Atlantis II, despite the near-identical populations in the overlying deep-sea waters. The lowest convective layers harbored interestingly similar microbial communities, even though temperature and heavy metal concentrations were very different. Multivariate analysis indicated that temperature and salinity were the major influences shaping the communities. The harsh conditions and the low-abundance phylotypes could explain the observed correlation in the brine pools.

scholarly journals Hydrogen Does Not Appear To Be a Major Electron Donor for Symbiosis with the Deep-Sea Hydrothermal Vent Tubeworm Riftia pachyptila

2019 ◽  
Vol 86 (1) ◽  
Author(s):  
Jessica H. Mitchell ◽  
Juliana M. Leonard ◽  
Jennifer Delaney ◽  
Peter R. Girguis ◽  
Kathleen M. Scott
Keyword(s):  
High Pressure ◽  
Electron Donor ◽  
Deep Sea ◽  
Symbiotic Association ◽  
Omics Data ◽  
Riftia Pachyptila ◽  
Free Living ◽  
Content Type ◽  
Genes Encoding ◽  
Chemolithoautotrophic Bacteria

ABSTRACT Use of hydrogen gas (H2) as an electron donor is common among free-living chemolithotrophic microorganisms. Given the presence of this dissolved gas at deep-sea hydrothermal vents, it has been suggested that it may also be a major electron donor for the free-living and symbiotic chemolithoautotrophic bacteria that are the primary producers at these sites. Giant Riftia pachyptila siboglinid tubeworms and their symbiotic bacteria (“Candidatus Endoriftia persephone”) dominate many vents in the Eastern Pacific, and their use of sulfide as a major electron donor has been documented. Genes encoding hydrogenase are present in the “Ca. Endoriftia persephone” genome, and proteome data suggest that these genes are expressed. In this study, high-pressure respirometry of intact R. pachyptila and incubations of trophosome homogenate were used to determine whether this symbiotic association could also use H2 as a major electron donor. Measured rates of H2 uptake by intact R. pachyptila in high-pressure respirometers were similar to rates measured in the absence of tubeworms. Oxygen uptake rates in the presence of H2 were always markedly lower than those measured in the presence of sulfide, as was the incorporation of 13C-labeled dissolved inorganic carbon. Carbon fixation by trophosome homogenate was not stimulated by H2, nor was hydrogenase activity detectable in these samples. Though genes encoding [NiFe] group 1e and [NiFe] group 3b hydrogenases are present in the genome and transcribed, it does not appear that H2 is a major electron donor for this system, and it may instead play a role in intracellular redox homeostasis. IMPORTANCE Despite the presence of hydrogenase genes, transcripts, and proteins in the “Ca. Endoriftia persephone” genome, transcriptome, and proteome, it does not appear that R. pachyptila can use H2 as a major electron donor. For many uncultivable microorganisms, omic analyses are the basis for inferences about their activities in situ. However, as is apparent from the study reported here, there are dangers in extrapolating from omics data to function, and it is essential, whenever possible, to verify functions predicted from omics data with physiological and biochemical measurements.

scholarly journals Rupture of the Cell Envelope by Decompression of the Deep-Sea Methanogen Methanococcus jannaschii

2002 ◽  
Vol 68 (3) ◽  
pp. 1458-1463 ◽  
Author(s):  
Chan Beum Park ◽  
Douglas S. Clark
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Hydrostatic Pressure ◽  
Deep Sea ◽  
Cell Envelope ◽  
Cell Lysis ◽  
Methanococcus Jannaschii ◽  
Hyperbaric Pressure ◽  
High Pressure High Temperature ◽  
Rapid Decompression

ABSTRACT The effect of decompression on the structure of Methanococcus jannaschii, an extremely thermophilic deep-sea methanogen, was studied in a novel high-pressure, high-temperature bioreactor. The cell envelope of M. jannaschii appeared to rupture upon rapid decompression (ca. 1 s) from 260 atm of hyperbaric pressure. When decompression from 260 atm was performed over 5 min, the proportion of ruptured cells decreased significantly. In contrast to the effect produced by decompression from hyperbaric pressure, decompression from a hydrostatic pressure of 260 atm did not induce cell lysis.

scholarly journals Deep Sea Microbes Probed by Incoherent Neutron Scattering Under High Hydrostatic Pressure

2014 ◽  
Vol 228 (10-12) ◽  
Author(s):  
Judith Peters ◽  
Nicolas Martinez ◽  
Grégoire Michoud ◽  
Anaïs Cario ◽  
Bruno Franzetti ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Neutron Scattering ◽  
Deep Sea ◽  
High Hydrostatic Pressure ◽  
Deep Biosphere ◽  
Incoherent Neutron Scattering ◽  
Incoherent Neutron ◽  
High Pressure Environment ◽  
Marine Biosphere

AbstractThe majority of the biosphere is a high pressure environment. Around 70% of the marine biosphere lies at depths below 1000 m, i.e. at pressures of 100 bars or higher. To survive in these environments, deep-biosphere organisms have adapted to life at high pressure.

scholarly journals Research and Analysis of Pressure-Maintaining Trapping Instrument for Macro-Organisms in Hadal Trenches

2020 ◽  
Vol 8 (8) ◽  
pp. 596
Author(s):  
Hao Wang ◽  
Jiawang Chen ◽  
Yuhong Wang ◽  
Jiasong Fang ◽  
Yuping Fang
Keyword(s):  
High Pressure ◽  
Hydrostatic Pressure ◽  
Deep Sea ◽  
High Hydrostatic Pressure ◽  
Explicit Method ◽  
Working Process ◽  
Ecosystem Research ◽  
Factors Affecting ◽  
Pressure Tests ◽  
Orthogonal Tests

The ecosystem of the abyss is one of the fields that humans hardly know. The ultra-high hydrostatic pressure makes it very difficult to obtain abyssal organisms. Samples are often severely broken during recovery due to changes in environmental pressure, temperature, and other factors. Currently, there are no macro-organism samplers suitable for the abyss. The development of a pressure-maintaining sampler for the abyss is a prerequisite for abyssal ecosystem research. This paper mainly proposed a pressure-maintaining trapping instrument (PMTI) designed to work at a depth above 10,000 m. Unlike typical deep-sea equipment, this instrument is lightweight (about 65 kg in water). The instrument adopts a new structure, using a hollow piston as the sampling space and sealing the mechanism with O-rings at both ends of the piston, thus avoiding sealing methods such as ball valves and greatly reducing the weight of the equipment. The structure and working process of the instrument are described in detail in this paper. Meanwhile, in this paper, the movement resistance of the piston (mainly the resistance of the O-ring) is analyzed using a dynamic explicit method in Abaqus. The factors affecting the friction of the O-rings are analyzed via the method of orthogonal tests and ANOVA. In addition, high-pressure tests were conducted on key parts of the instrument, and the results showed that the instrument works well at 100 MPa.

scholarly journals Abundance and Genetic Diversity of Aerobic Anoxygenic Phototrophic Bacteria of Coastal Regions of the Pacific Ocean

2012 ◽  
Vol 78 (8) ◽  
pp. 2858-2866 ◽  
Author(s):  
Anna E. Ritchie ◽  
Zackary I. Johnson
Keyword(s):  
Genetic Diversity ◽  
Pacific Ocean ◽  
Environmental Variables ◽  
Anoxygenic Phototrophic Bacteria ◽  
Bacterial Populations ◽  
Content Type ◽  
The Pacific ◽  
Near Shore ◽  
The Pacific Ocean ◽  
Abundance And Diversity

ABSTRACTAerobic anoxygenic phototrophic (AAP) bacteria are photoheterotrophic microbes that are found in a broad range of aquatic environments. Although potentially significant to the microbial ecology and biogeochemistry of marine ecosystems, their abundance and genetic diversity and the environmental variables that regulate these properties are poorly understood. Using samples along nearshore/offshore transects from five disparate islands in the Pacific Ocean (Oahu, Molokai, Futuna, Aniwa, and Lord Howe) and off California, we show that AAP bacteria, as quantified by thepufMgene biomarker, are most abundant near shore and in areas with high chlorophyll orSynechococcusabundance. These AAP bacterial populations are genetically diverse, with most members belonging to the alpha- or gammaproteobacterial groups and with subclades that are associated with specific environmental variables. The genetic diversity of AAP bacteria is structured along the nearshore/offshore transects in relation to environmental variables, and unculturedpufMgene libraries suggest that nearshore communities are distinct from those offshore. AAP bacterial communities are also genetically distinct between islands, such that the stations that are most distantly separated are the most genetically distinct. Together, these results demonstrate that environmental variables regulate both the abundance and diversity of AAP bacteria but that endemism may also be a contributing factor in structuring these communities.

scholarly journals Pressure-Induced Endocytic Degradation of the Saccharomyces cerevisiae Low-Affinity Tryptophan Permease Tat1 Is Mediated by Rsp5 Ubiquitin Ligase and Functionally Redundant PPxY Motif Proteins

2013 ◽  
Vol 12 (7) ◽  
pp. 990-997 ◽  
Author(s):  
Asaha Suzuki ◽  
Takahiro Mochizuki ◽  
Satoshi Uemura ◽  
Toshiki Hiraki ◽  
Fumiyoshi Abe
Keyword(s):  
Saccharomyces Cerevisiae ◽  
High Pressure ◽  
Hydrostatic Pressure ◽  
Ubiquitin Ligase ◽  
High Hydrostatic Pressure ◽  
Intracellular Localization ◽  
Normal Growth ◽  
Growth Conditions ◽  
Content Type ◽  
Genes Encoding

ABSTRACT Cells of Saccharomyces cerevisiae express two tryptophan permeases, Tat1 and Tat2, which have different characteristics in terms of their affinity for tryptophan and intracellular localization. Although the high-affinity permease Tat2 has been well documented in terms of its ubiquitin-dependent degradation, the low-affinity permease Tat1 has not yet been characterized fully. Here we show that a high hydrostatic pressure of 25 MPa triggers a degradation of Tat1 which depends on Rsp5 ubiquitin ligase and the EH domain-containing protein End3. Tat1 was resistant to a 3-h cycloheximide treatment, suggesting that it is highly stable under normal growth conditions. The ubiquitination of Tat1 most likely occurs at N-terminal lysines 29 and 31. Simultaneous substitution of arginine for the two lysines prevented Tat1 degradation, but substitution of either of them alone did not, indicating that the roles of lysines 29 and 31 are redundant. When cells were exposed to high pressure, Tat1-GFP was completely lost from the plasma membrane, while substantial amounts of Tat1 K29R-K31R -GFP remained. The HPG1-1 (Rsp5 P514T ) and rsp5-ww3 mutations stabilized Tat1 under high pressure, but any one of the rsp5-ww1 , rsp5-ww2 , and bul1 Δ bul2 Δ mutations or single deletions of genes encoding arrestin-related trafficking adaptors did not. However, simultaneous loss of 9-arrestins and Bul1/Bul2 prevented Tat1 degradation at 25 MPa. The results suggest that multiple PPxY motif proteins share some essential roles in regulating Tat1 ubiquitination in response to high hydrostatic pressure.

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