The Bacteriohopanepolyol Inventory of Novel Aerobic Methane Oxidising Bacteria Reveals New Biomarker Signatures of Aerobic Methanotrophy in Marine Systems.
Aerobic methane oxidation (AMO) is one of the primary biologic pathways regulating the amount of methane (CH4) released into the environment. AMO acts as a sink of CH4, converting it into carbon dioxide before it reaches the atmosphere. It is of interest for (paleo)climate and carbon cycling studies to identify lipid biomarkers that can be used to trace AMO events, especially at times when the role of methane in the carbon cycle was more pronounced than today. AMO bacteria are known to synthesise bacteriohopanepolyol (BHP) lipids. Preliminary evidence pointed towards 35-aminobacteriohopane-30,31,32,33,34-pentol (aminopentol) being a characteristic biomarker for Type I methanotrophs. Here, the BHP compositions were examined for species of the recently described novel Type I methanotroph bacterial genera Methylomarinum and Methylomarinovum, as well as for a novel species of a Type I Methylomicrobium. Aminopentol was the most abundant BHP only in Methylomarinovum caldicuralii, while Methylomicrobium did not produce aminopentol at all. In addition to the expected regular aminotriol and aminotetrol BHPs, novel structures tentatively identified as methylcarbamate lipids related to C-35 amino-BHPs (MC-BHPs) were found to be synthesised in significant amounts by some AMO cultures. Subsequently, sediments and authigenic carbonates from methane-influenced marine environments were analysed. Most samples also did not contain significant amounts of aminopentol, indicating that aminopentol is not a useful biomarker for marine aerobic methanotophic bacteria. However, the BHP composition of the marine samples do point toward the novel MC-BHPs components being potential new biomarkers for AMO.
School of Civil Engineering & Geosciences, Newcastle University, Drummond Building, Newcastle upon Tyne, NE1 7RU, Newcastle-upon-Tyne, United Kingdom.
Darci
http://orcid.org/0000-0002-6567-4116
D
Rush
School of Civil Engineering & Geosciences, Newcastle University, Drummond Building, Newcastle upon Tyne, NE1 7RU, Newcastle-upon-Tyne, United Kingdom.
Kate A
KA
Osborne
Institute of Geology, University of Hamburg, Hamburg, Germany.
Daniel
D
Birgel
Center for Applied Geoscience, University of Tübingen, Tübingen, Germany.|Center for Geomicrobiology, Department of Bioscience, Ny Munkegade 116, 8000, Aarhus C, Denmark.
Andreas
A
Kappler
Department of Subsurface Geobiological Analysis and Research, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), Yokosuka, Japan.
Hisako
H
Hirayama
Institute of Geology, University of Hamburg, Hamburg, Germany.|Department of Geodynamics and Sedimentology, University of Vienna, 1090, Vienna, Austria.
Jörn
J
Peckmann
School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom.
Simon W
SW
Poulton
GFZ German Research Centre for Geosciences, Telegrafenberg, D-14473, Potsdam, Germany.
Julia C
JC
Nickel
GFZ German Research Centre for Geosciences, Telegrafenberg, D-14473, Potsdam, Germany.
Kai
K
Mangelsdorf
Faculty of Biology, San Diego State University, 5500 Campanile Drive, San Diego, 92182, United States of America.
Marina
M
Kalyuzhnaya
School of Civil Engineering & Geosciences, Newcastle University, Drummond Building, Newcastle upon Tyne, NE1 7RU, Newcastle-upon-Tyne, United Kingdom.
Frances R
FR
Sidgwick
School of Civil Engineering & Geosciences, Newcastle University, Drummond Building, Newcastle upon Tyne, NE1 7RU, Newcastle-upon-Tyne, United Kingdom.
Helen M
HM
Talbot
D000332:Aerobiosis; D059001:Aquatic Organisms / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D002264:Carboxylic Acids / Q000378:metabolism; D017753:Ecosystem; D019015:Geologic Sediments / Q000032:analysis / Q000382:microbiology; D008055:Lipids / Q000032:analysis; D008697:Methane / Q000378:metabolism; D008772:Methylococcaceae / Q000378:metabolism*
D015415:Biomarkers; D002264:Carboxylic Acids; D008055:Lipids; C110744:aminopentol; D008697:Methane