Biogeochemical cycling in an organic-rich coastal marine basin. 10. The role of amino acids in sedimentary carbon and nitrogen cycling

Journal Article · Wed Jun 01 04:00:00 EDT 1988 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(88)90226-8· OSTI ID:5399031

Burdige, D J; Martens, C S ^[1]

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1. Univ. of North Carolina, Chapel Hill (USA)

Hydrolyzable amino acids were measured in cores and surface sediment samples collected over a 14 month period from the rapidly accumulating, anoxic sediments of Cape Lookout Bight, NC. The concentration of total hydrolyzable amino acids (THAAs) shows an exponential decrease with depth, in a manner similar to total organic carbon and total nitrogen. Carbon and nitrogen in THAAs averages 10-15% of the total organic carbon and 30-40% of the total nitrogen in these sediments. In surface sediments the concentration of THAAs do not show strong seasonal variations, with the exception of a small apparent decrease during the winter months. Aspartic acid, glutamic acid, glycine and alanine are the most abundant individual amino acids in Cape Lookout Bight sediments. The distribution of individual amino acids in these sediments is very similar to that observed in the two major sources of organic matter, vascular salt marsh plants and marine plankton. The mole fractions of most amino acids show no depth variation in Cape Lookout Bight sediments. Kinetic modeling of these data indicates that the deposition of amino acids to the surface of these sediments is 5.8 {plus minus} 1.0 mol{center dot}m{sup {minus}2}{center dot}yr{sup {minus}1}. Approximately 46 {plus minus} 16% of this input is remineralized in the upper 40 cm. The recycling of amino acids accounts for 82 {plus minus} 43% of the total nitrogen regeneration and 27 {plus minus} 11% of the regeneration of total organic carbon in these sediments. The mean residence time of metabolizable amino acids is approx. 9 months, a value which is comparable to the mean residence time of both metabolizable organic carbon and nitrogen in these sediments.

• OSTI ID: 5399031
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 52:6; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580400* -- Geochemistry-- (-1989)
AGE ESTIMATION
AMINO ACIDS
ATLANTIC OCEAN
BIOGEOCHEMISTRY
CARBON
CARBOXYLIC ACIDS
CHEMICAL COMPOSITION
CHEMISTRY
CONCENTRATION RATIO
DRILL CORES
ELEMENTS
FEDERAL REGION IV
GEOCHEMISTRY
GEOLOGIC STRUCTURES
KINETICS
MATHEMATICAL MODELS
MINERAL CYCLING
NITROGEN
NONMETALS
NORTH AMERICA
NORTH CAROLINA
OFFSHORE SITES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC MATTER
PARTICLE MODELS
PRECIPITATION
REACTION KINETICS
SEAS
SEASONAL VARIATIONS
SEDIMENTARY BASINS
SEDIMENTS
SEPARATION PROCESSES
STATISTICAL MODELS
SURFACE WATERS
THERMODYNAMIC MODEL
USA
VARIATIONS