title: Measuring bacterial activity and community composition at high hydrostatic pressure using a novel experimental approach: a pilot study.
abstract: In this pilot study, we describe a high-pressure incubation system allowing multiple subsampling of a pressurized culture without decompression. The system was tested using one piezophilic (Photobacterium profundum), one piezotolerant (Colwellia maris) bacterial strain and a decompressed sample from the Mediterranean deep sea (3044 m) determining bacterial community composition, protein production (BPP) and cell multiplication rates (BCM) up to 27 MPa. The results showed elevation of BPP at high pressure was by a factor of 1.5 ± 1.4 and 3.9 ± 2.3 for P. profundum and C. maris, respectively, compared to ambient-pressure treatments and by a factor of 6.9 ± 3.8 fold in the field samples. In P. profundum and C. maris, BCM at high pressure was elevated (3.1 ± 1.5 and 2.9 ± 1.7 fold, respectively) compared to the ambient-pressure treatments. After 3 days of incubation at 27 MPa, the natural bacterial deep-sea community was dominated by one phylum of the genus Exiguobacterium, indicating the rapid selection of piezotolerant bacteria. In future studies, our novel incubation system could be part of an isopiestic pressure chain, allowing more accurate measurement of bacterial activity rates which is important both for modeling and for predicting the efficiency of the oceanic carbon pump.
authors: Leibniz Institute for Baltic Sea Research, Seestrasse 15, 18119 Rostock, Germany Leibniz Institute of Freshwater Ecology and Inland Fisheries, Dept. of Experimental Limnology, Alte Fischerhuette 2, D-16775 Stechlin, Germany nicola.wannicke@io-warnemuende.de.
authors: Nicola
authors: N
authors: Wannicke
authors: Department of Soil Science, Institute for Crop Science and Resource Conservation (INRES), Bonn University, Nussallee 13, D-53115 Bonn, Germany.
authors: Katharina
authors: K
authors: Frindte
authors: Hamburg University of Technology, Institute for Product Development and Mechanical Engineering Design, Denickestrasse 17, D-21073 Hamburg, Germany.
authors: Giselher
authors: G
authors: Gust
authors: Leibniz Institute for Baltic Sea Research, Seestrasse 15, 18119 Rostock, Germany.
authors: Iris
authors: I
authors: Liskow
authors: Institute for Biochemistry and Biology, Potsdam University, Am Neuen Palais 10, D-14469 Potsdam, Germany.
authors: Alexander
authors: A
authors: Wacker
authors: Technik Service A. Meyer, Sanderweg 7a, D-24214 Lindau, Germany.
authors: Andreas
authors: A
authors: Meyer
authors: Leibniz Institute of Freshwater Ecology and Inland Fisheries, Dept. of Experimental Limnology, Alte Fischerhuette 2, D-16775 Stechlin, Germany Institute for Biochemistry and Biology, Potsdam University, Am Neuen Palais 10, D-14469 Potsdam, Germany.
authors: Hans-Peter
authors: HP
authors: Grossart
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D034241:Alteromonadaceae / Q000378:metabolism* / Q000502:physiology*; D018533:Biomass; D005227:Fatty Acids / Q000378:metabolism; D006874:Hydrostatic Pressure; D007553:Isotope Labeling; D009792:Oceans and Seas; D010743:Phospholipids / Q000378:metabolism; D010776:Photobacterium / Q000378:metabolism* / Q000502:physiology*; D010865:Pilot Projects; D011312:Pressure
chemical_list: D005227:Fatty Acids; D010743:Phospholipids
keywords: bacterial production; deep-sea bacterial community; hydrostatic pressure; membrane fatty acids; piezophilic bacteria; pressure chamber; stable isotopes