Distribution of major carbon pools in a cyanobacterial mat from Salin de Giraud, Camargue, France


Autoria(s): Wieland, Andrea; Pape, Thomas; Möbius, Jürgen; Klock, Jan-Hendrik; Michaelis, Walter
Cobertura

LATITUDE: 43.399200 * LONGITUDE: 4.756100

Data(s)

17/11/2008

Resumo

The fine-scale depth distribution of major carbon pools and their stable carbon isotopic signatures (d13C) were determined in a cyanobacterial mat (Salin-de-Giraud, Camargue, France) to study early diagenetic alterations and the carbon preservation potential in hypersaline mat ecosystems. Particular emphasis was placed on the geochemical role of extracellular polymeric substances (EPS). Total carbon (Ctot), organic carbon (Corg), total nitrogen (Ntot), total hydrolysable amino acids (THAA), carbohydrates, cyanobacteria-derived hydrocarbons (8-methylhexadecane, n-heptadec-5-ene, n-heptadecane) and EPS showed highest concentrations in the top millimetre of the mat and decreased with depth. The hydrocarbons attributed to cyanobacteria showed the strongest decrease in concentration with depth. This correlated well with the depth profiles of oxygenic photosynthesis and oxygen, which were detected in the top 0.6 and 1.05 mm, respectively, at a high down-welling irradiance (1441 µmol photons m**-2 s**-1). At depths beneath the surface layer, the Corg was composed mainly of amino acids and carbohydrates. A resistance towards microbial degradation could have resulted from interactions with diverse functional groups present in biopolymers (EPS) and with minerals deposited in the mat. A 13C enrichment with depth for the total carbon pool (Ctot) was observed, with d13C values ranging from -16.3 permil at the surface to -11.3 permil at 9-10 mm depth. Total lipids depicted a d13C value of -17.2 permil in the top millimetre and then became depleted in 13C with depth (-21.7 to -23.3 permil). The d13C value of EPS varied only slightly with depth (-16.1 to -17.3 permil) and closely followed the d13C value of Corg at depths beneath 4 mm. The EPS represents an organic carbon pool of preservation potential during early stages of diagenesis in recent cyanobacterial mats as a result of a variety of possible interactions. Their analyses might improve our understanding of fossilized microbial remains from mat ecosystems.

Formato

application/zip, 4 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.771475

doi:10.1594/PANGAEA.771475

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Wieland, Andrea; Pape, Thomas; Möbius, Jürgen; Klock, Jan-Hendrik; Michaelis, Walter (2008): Carbon pools and isotopic trends in a hypersaline cyanobacterial mat (Salin-de-Giraud, France). Geobiology, 6, 171-186, doi:10.1111/j.1472-4669.2007.00138.x

Palavras-Chave #% AA-Corg; % AA-Ntot; %glucose-Corg; % of Ctot; Amino acid, total hydrolysable; Amino acid analyser, Biochrom 30; C/N; C/N-EPS; Calculated; Carbohydrates; Carbohydrates, total; Carbon, inorganic, total; Carbon, organic, total; Carbon, total; Carbon/Nitrogen ratio; Center for Marine Environmental Sciences; C-EPS; CHO; CHO tot; Ctot, dw; Depth; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Depth bot; Depth top; Element analyser CNS, Carlo Erba NA1500; February 2005; Hand corer; HCOR; in glucose equivalents; in glucose equivalents, February 2005; MARUM; N-EPS; Nitrogen, total; Reactivity index of amino acids (Jennerjahn & Ittekkot, 1997); RI; Salin-de-Giraud; Salin de Giraud, Camargue, France; Spectrophotometry; TC; THAA; TIC; TN; TOC
Tipo

Dataset