@article{fdi:010075583,
  title = {{P}ressure-retaining sampler and high-pressure systems to study deep-sea microbes under in situ conditions},
  author = {{G}arel, {M}. and {B}onin, {P}. and {M}artini, {S}. and {G}uasco, {S}. and {R}oumagnac, {M}. and {B}hairy, {N}. and {A}rmougom, {F}abrice and {T}amburini, {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he pelagic realm of the dark ocean is characterized by high hydrostatic pressure, low temperature, high-inorganic nutrients, and low organic carbon concentrations. {M}easurements of metabolic activities of bathypelagic bacteria are often underestimated due to the technological limitations in recovering samples and maintaining them under in situ environmental conditions. {M}oreover, most of the pressure-retaining samplers, developed by a number of different labs, able to maintain seawater samples at in situ pressure during recovery have remained at the prototype stage, and therefore not available to the scientific community. {I}n this paper, we will describe a ready-to-use pressure-retaining sampler, which can be adapted to use on a {CTD}-carousel sampler. {A}s well as being able to recover samples under in situ high pressure (up to 60 {MP}a) we propose a sample processing in equi-pressure mode. {U}sing a piloted pressure generator, we present how to perform sub-sampling and transfer of samples in equi-pressure mode to obtain replicates and perform hyperbaric experiments safely and efficiently (with <2% pressure variability). {A}s proof of concept, we describe a field application (prokaryotic activity measurements and incubation experiment) with samples collected at 3,000m-depth in the {M}editerranean {S}ea. {S}ampling, sub-sampling, transfer, and incubations were performed under in situ high pressure conditions and compared to those performed following decompression and incubation at atmospheric pressure. {T}hree successive incubations were made for each condition using direct dissolved-oxygen concentration measurements to determine the incubation times. {S}ubsamples were collected at the end of each incubation to monitor the prokaryotic diversity, using 16{S}-r{DNA}/r{RNA} high-throughput sequencing. {O}ur results demonstrated that oxygen consumption by prokaryotes is always higher under in situ conditions than after decompression and incubation at atmospheric pressure. {I}n addition, over time, the variations in the prokaryotic community composition and structure are seen to be driven by the different experimental conditions. {F}inally, within samples maintained under in situ high pressure conditions, the active (16{S} r{RNA}) prokaryotic community was dominated by sequences affiliated with rare families containing piezophilic isolates, such as {O}ceanospirillaceae or {C}olwelliaceae. {T}hese results demonstrate the biological importance of maintaining in situ conditions during and after sampling in deep-sea environments.},
  keywords = {pressure-retaining sampler ; deep sea ; in situ sampling ; prokaryotic activities ; prokaryotic diversity ; {MEDITERRANEE}},
  booktitle = {},
  journal = {{F}rontiers in {M}icrobiology},
  volume = {10},
  numero = {},
  pages = {art. 453 [13 p.]},
  ISSN = {1664-302{X}},
  year = {2019},
  DOI = {10.3389/fmicb.2019.00453},
  URL = {https://www.documentation.ird.fr/hor/fdi:010075583},
}