Optimizing sample pretreatment for compound-specific stable carbon isotopic analysis of amino sugars in marine sediment

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doi: 10.5194/bg-11-4869-2014
Author(s): Zhu, R.; Lin, Y. S.; Lipp, J. S.; Meador, T. B.; Hinrichs, K. U.
Author Affiliation(s): Primary:
University of Bremen, MARUM-Center for Marine Environmental Sciences, Bremen, Germany
Volume Title: Biogeosciences
Source: Biogeosciences, 11(17), p.4869-4880. Publisher: Copernicus GmbH on behalf of the European Union, Katlenburg-Lindau, International. ISSN: 1726-4170
Note: In English. 49 refs.; illus., incl. 4 tables
Summary: Amino sugars are quantitatively significant constituents of soil and marine sediment, but their sources and turnover in environmental samples remain poorly understood. The stable carbon isotopic composition of amino sugars can provide information on the lifestyles of their source organisms and can be monitored during incubations with labeled substrates to estimate the turnover rates of microbial populations. However, until now, such investigation has been carried out only with soil samples, partly because of the much lower abundance of amino sugars in marine environments. We therefore optimized a procedure for compound-specific isotopic analysis of amino sugars in marine sediment, employing gas chromatography-isotope ratio mass spectrometry. The whole procedure consisted of hydrolysis, neutralization, enrichment, and derivatization of amino sugars. Except for the derivatization step, the protocol introduced negligible isotopic fractionation, and the minimum requirement of amino sugar for isotopic analysis was 20 ng, i.e., equivalent to ∼8 ng of amino sugar carbon. Compound-specific stable carbon isotopic analysis of amino sugars obtained from marine sediment extracts indicated that glucosamine and galactosamine were mainly derived from organic detritus, whereas muramic acid showed isotopic imprints from indigenous bacterial activities. The δ13C analysis of amino sugars provides a valuable addition to the biomarker-based characterization of microbial metabolism in the deep marine biosphere, which so far has been lipid oriented and biased towards the detection of archaeal signals.
Year of Publication: 2014
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; Amino acids; Asia; Biomarkers; Black Sea; C-13/C-12; Carbohydrates; Carbon; Central Europe; Chemical analysis; Chromatograms; Chromatography; Composition; Concentration; Data processing; Depositional environment; Derivatization; Desalinization; East Mediterranean; Europe; Experimental studies; Gas chromatograms; Gas chromatography; Germany; Hydrolysis; Indian Peninsula; Instruments; Isotope fractionation; Isotopes; Leg 201; Liquid chromatography; Marine environment; Marine sediments; Mass spectroscopy; Mathematical methods; Mediterranean Sea; Metabolism; Methods; Microorganisms; Middle East; Neutralization; Ocean Drilling Program; Optimization; Organic acids; Organic compounds; Pakistan; Peru; Purification; Sample preparation; Sampling; Sea of Marmara; Sediments; Separation; South America; Spectroscopy; Stable isotopes; Sugars; Techniques; Turkey; Wadden Sea; Western Europe; Wremen Germany
Coordinates: N533800 N533800 E0082930 E0082930
S120500 N035000 W0775500 W1103500
N233500 N373000 E0751500 E0601500
N410000 N470000 E0420000 E0280000
N401500 N410500 E0300000 E0264000
Record ID: 2017017402
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Copernicus Gesellschaft, Katlenburg-Lindau, Germany