title: A new tool for long-term studies of POM-bacteria interactions: overcoming the century-old Bottle Effect.
abstract: Downward fluxes of particulate organic matter (POM) are the major process for sequestering atmospheric CO2 into aquatic sediments for thousands of years. Budget calculations of the biological carbon pump are heavily based on the ratio between carbon export (sedimentation) and remineralization (release to the atmosphere). Current methodologies determine microbial dynamics on POM using closed vessels, which are strongly biased towards heterotrophy due to rapidly changing water chemistry (Bottle Effect). We developed a flow-through rolling tank for long term studies that continuously maintains POM at near in-situ conditions. There, bacterial communities resembled in-situ communities and greatly differed from those in the closed systems. The active particle-associated community in the flow-through system was stable for days, contrary to hours previously reported for closed incubations. In contrast to enhanced respiration rates, the decrease in photosynthetic rates on particles throughout the incubation was much slower in our system than in traditional ones. These results call for reevaluating experimentally-derived carbon fluxes estimated using traditional methods.
authors.affiliation: Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhuette 2, OT Neuglobsow, 16775, Stechlin, Germany.
authors.forename: Danny
authors.initials: D
authors.lastname: Ionescu
authors.affiliation: Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhuette 2, OT Neuglobsow, 16775, Stechlin, Germany.
authors.forename: Mina
authors.initials: M
authors.lastname: Bizic-Ionescu
authors.affiliation: Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, 28359, Bremen, Germany.
authors.forename: Arzhang
authors.initials: A
authors.lastname: Khalili
authors.affiliation: Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, 28359, Bremen, Germany.
authors.forename: Reza
authors.initials: R
authors.lastname: Malekmohammadi
authors.affiliation: Sharif University of Technology, Azadi str', 1458889694, Teheran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Morad
authors.affiliation: Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, 28359, Bremen, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: de Beer
authors.affiliation: Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhuette 2, OT Neuglobsow, 16775, Stechlin, Germany.|Institute for Biochemistry and Biology, Potsdam University, Maulbeerallee 2, 14469,10 Potsdam, Germany.
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Grossart
mesh_terms: D001429:Bacteriochlorophylls / Q000737:chemistry; D046508:Culture Techniques; D000458:Cyanobacteria / Q000502:physiology*; D059014:High-Throughput Nucleotide Sequencing; D064307:Microbiota; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry*; D010788:Photosynthesis; D014871:Water Microbiology
chemical_list: D001429:Bacteriochlorophylls; D052638:Particulate Matter