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 Picoplankton Distribution and Activity in the Deep Waters of the Southern Adriatic Sea

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1655 ◽  
Author(s):  
Danijela Šantić ◽  
Vedrana Kovačević ◽  
Manuel Bensi ◽  
Michele Giani ◽  
Ana Vrdoljak Tomaš ◽  
...  
Keyword(s):  
Deep Sea ◽  
Large Scale ◽  
Heterotrophic Bacteria ◽  
Eastern Mediterranean ◽  
Environmental Parameters ◽  
Anoxygenic Phototrophic Bacteria ◽  
Heterotrophic Nanoflagellates ◽  
Nucleic Acid Content ◽  
Viral Lysis ◽  
Deep Waters

Southern Adriatic (Eastern Mediterranean Sea) is a region strongly dominated by large-scale oceanographic processes and local open-ocean dense water formation. In this study, picoplankton biomass, distribution, and activity were examined during two oceanographic cruises and analyzed in relation to environmental parameters and hydrographic conditions comparing pre and post-winter phases (December 2015, April 2016). Picoplankton density with the domination of autotrophic biomasses was higher in the pre-winter phase when significant amounts of picoaoutotrophs were also found in the meso-and bathy-pelagic layers, while Synechococcus dominated the picoautotrophic group. Higher values of bacterial production and domination of High Nucleic Acid content bacteria (HNA bacteria) were found in deep waters, especially during the post-winter phase, suggesting that bacteria can have an active role in the deep-sea environment. Aerobic anoxygenic phototrophic bacteria accounted for a small proportion of total heterotrophic bacteria but contributed up to 4% of bacterial carbon content. Changes in the picoplankton community were mainly driven by nutrient availability, heterotrophic nanoflagellates abundance, and water mass movements and mixing. Our results suggest that autotrophic and heterotrophic members of the picoplankton community are an important carbon source in the food web in the deep-sea, as well as in the epipelagic layer. Besides, viral lysis may affect the activity of the picoplankton community and enrich the water column with dissolved organic carbon.

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 Enhanced Hydrocarbons Biodegradation at Deep-Sea Hydrostatic Pressure with Microbial Electrochemical Snorkels

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 263
Author(s):  
Federico Aulenta ◽  
Enza Palma ◽  
Ugo Marzocchi ◽  
Carolina Cruz Viggi ◽  
Simona Rossetti ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Deep Sea ◽  
Sulfide Oxidation ◽  
Contaminated Sediments ◽  
Sulfide Concentration ◽  
Deep Sea Sediments ◽  
Toxicity Factor ◽  
Remote Environment ◽  
Additional Limitation ◽  
Oxide Sulfate

In anaerobic sediments, microbial degradation of petroleum hydrocarbons is limited by the rapid depletion of electron acceptors (e.g., ferric oxide, sulfate) and accumulation of toxic metabolites (e.g., sulfide, following sulfate reduction). Deep-sea sediments are increasingly impacted by oil contamination, and the elevated hydrostatic pressure (HP) they are subjected to represents an additional limitation for microbial metabolism. While the use of electrodes to support electrobioremediation in oil-contaminated sediments has been described, there is no evidence on their applicability for deep-sea sediments. Here, we tested a passive bioelectrochemical system named ”oil-spill snorkel” with two crude oils carrying different alkane contents (4 vs. 15%), at increased or ambient HP (10 vs. 0.1 MPa). Snorkels enhanced alkanes biodegradation at both 10 and 0.1 MPa within only seven weeks, as compared to nonconductive glass controls. Microprofiles in anaerobic, contaminated sediments indicated that snorkels kept sulfide concentration to low titers. Bulk-sediment analysis confirmed that sulfide oxidation by snorkels largely regenerated sulfate. Hence, the sole application of snorkels could eliminate a toxicity factor and replenish a spent electron acceptor at increased HP. Both aspects are crucial for petroleum decontamination of the deep sea, a remote environment featured by low metabolic activity.

scholarly journals Effect of Harvest Date on Mango (Mangifera Indica L. Cultivar Osteen) Fruit’s Qualitative Development, Shelf Life and Consumer Acceptance

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 811
Author(s):  
Giuseppe Gianguzzi ◽  
Vittorio Farina ◽  
Paolo Inglese ◽  
Maria Gloria Lobo Rodrigo
Keyword(s):  
Management Practices ◽  
Mangifera Indica ◽  
Storage Period ◽  
Environmental Parameters ◽  
Internal Quality ◽  
Harvest Management ◽  
Post Harvest ◽  
Full Flowering ◽  
Constant Quality ◽  
Definition Of

The qualitative characteristics of mango fruits change throughout their development process and are also influenced by their duration. Harvesting at different times after the fruit set affects external and internal quality and the post-harvest behavior and management possibilities of the fruits. The objective of this study was to assess the evolution of the most important physicochemical and organoleptic parameters of cv. Osteen fruits concern the length of their stay on the plant and also to their post-harvest management. For this reason, fruits were harvested progressively in ten pickings. The study showed that mango fruits that are kept on the tree reach the best quality traits, corresponding to their physiological maturation. The length of the storage period needed to reach the consumption point varies greatly according to the harvesting moment and to the different environmental parameters, which also affect the organoleptic and physicochemical quality of the fruits. The number of days after full flowering were confirmed to be the primary information to consider when planning harvest with commercial use of the fruit, but interesting indications can be acquired through the definition of non-destructive (hardness, color) or destructive (dry matter) parameters. The data collected help improve mango fruit′s post-harvest management practices, to provide a product with constant quality and homogeneity to the consumer.

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 Ultra-small cells and DPANN genome unveiled inside an extinct vent chimney

2021 ◽  
Author(s):  
Hinako Takamiya ◽  
Mariko Kouduka ◽  
Hitoshi Furutani ◽  
Hiroki Mukai ◽  
Takushi Yamamoto ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Grain Boundaries ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
Single Gene ◽  
Metal Sulfide ◽  
Small Cells ◽  
Acid Fermentation ◽  
Microbial Life ◽  
Fluid Venting

AbstractChemosynthetic organisms flourish around deep-sea hydrothermal vents where energy-rich fluids are emitted from metal sulfide chimneys. In contrast to actively venting chimneys, the nature of microbial life in extinct chimneys without fluid venting remains largely unknown. Here, the occurrence of ultra-small cells in silica-filled grain boundaries inside an extinct chimney is demonstrated by high-resolution bio-signature mapping. The ultra-small cells are associated with extracellularly precipitated Cu2O nanocrystals. Single-gene analysis shows that the chimney interior is dominated by a member of Pacearchaeota known as a major phylum of DPANN. Genome-resolved metagenomic analysis reveals that the chimney Pacearchaeota member is equipped with a nearly full set of genes for fermentation-based energy generation from nucleic acids, in contrast to previously characterized Pacearchaeota members lacking many genes for nucleic acid fermentation. We infer that the ultra-small cells associated with silica and extracellular Cu2O nanocrystals in the grain boundaries are Pacearchaeota, on the basis of the experimentally demonstrated capability of silica to concentrate nucleic acids from seawater and the presence of Cu-exporting genes in a reconstructed Pacearchaeota genome. Given the existence of ~3-billion-year-old submarine hydrothermally deposited silica, proliferation of microbial life using silica-bound nucleic acids might be relevant to the primitive vent biosphere.

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