High molecular weight (HMW) dissolved organic matter (DOM) in seawater : chemical structure, sources and cycling

Aluwihare, Lihini I.

doi:10.1575/1912/4715

Cited by 7 publications

(4 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other calibration studies with 1000 Da polysulfone cartridges (Guo & Santschi 1996) have found lower absorption losses and better retention characteristics for Vitamin B-12 (80%) and for various proteins (between 93 and 97%). Aluwihare (1999) reported retention of 80 ± 10% for carbohydrate and 50% for protein. Retention of carbohydrate and protein of the cartridge used in our study was 53 and 14%, respectively, suggesting that more protein than carbohydrate was lost to the cartridge membrane.…”

Section: Possible Factors Contributing To Differences In Reported C:nmentioning

confidence: 97%

“…However, analyses of the composition of Phaeocystis extracellular polymers without the inclusion of cells are few (Biersmith & Benner 1998, Aluwihare 1999, Aluwihare & Repeta 1999, and are available for only 2 strains of P. globosa in bacterized cultures. In this study, we examined the chemical composition of axenic and bacterized extracellular polymers from another strain of P. globosa and from P. antarctica, which has not been previously characterized.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of extracellular polymers of Phaeocystis globosa and P. antarctica

Solomon¹,

Lessard²,

Keil³

et al. 2003

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Extracellular polymers of Phaeocystis globosa and P. antarctica were characterized by elemental analysis, X-ray photoelectron spectroscopy (XPS), and matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis. The 2 species were grown in axenic and bacterized cultures to examine the effect of bacterial degradation on the composition of the extracellular polymers. The C:N ratios for extracellular polymers from P. globosa and P. antarctica grown under these conditions were lower (< 9) than in previous reports (>12). P. antarctica polymer C:N was significantly lower than that of P. globosa. Contrary to expectations, the polymer C:N from bacterized cultures was slightly lower than from axenic cultures. XPS analysis indicated that the polymers are carbohydrate-rich, and MALDI-TOF-MS analysis showed that the nitrogen was not proteinaceous, but probably originated from low molecular weight compounds such as amino sugars. The low C:N ratios suggest that extracellular polymers may directly provide a substrate for bacteria and heterotrophic protists without the need for other sources of nitrogen.

show abstract

Section: Possible Factors Contributing To Differences In Reported C:nmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Characterization of extracellular polymers of Phaeocystis globosa and P. antarctica

Solomon¹,

Lessard²,

Keil³

et al. 2003

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…Santschi et aI., 1995;Bauer et al, 1998;Aluwihare, 1999), in which DOC consists of a portion of recently-synthesized algal exudate (probably a carbohydrate polymer, Aluwihare et aI., 1997) combined with a refractory, 14C_poor, component. We do not have a complete 14C data set with which to apply this model to analysis of our 5MB and SBB data; however, with some reasonable approximations, the following analysis is possible.…”

Section: Doc Incorporation Modelmentioning

confidence: 99%

“…Aluwihare (1999) estimates this component comprises 2-3% of the total DOC, while Santschi et al (1995) reported the modern component is 3-5% of total DOC. A mass balance calculation using 3% modern 14C leaves the 97% (refractory) component These results indicate DOC incorporation is an unlikely mechanism to explain the "old" archaeal 14C concentrations for three reasons.…”

Section: Doc Incorporation Modelmentioning

confidence: 99%

Biogeochemical applications of compound-specific radiocarbon analysis

Pearson¹

1999

View full text Add to dashboard Cite

Compound-specific carbon isotopic (013C and !J.14C) data are reported for lipid biomarkers isolated from Santa Monica Basin (SMB) and Santa Barbara Basin (SBB) surface sediments. These organic compounds represent phytoplanktonic, zooplanktonic, bacterial, archaeal, terrestrial, and fossil carbon sources. The lipids include long-chain n-alkanes, fatty acids (as FAMEs), n-alcohols, C 30 mid-chain ketols and diols, sterols, hopanols, and ether-linked C4o-biphytanes of Archaea.The data show that the carbon source for most of the biomarkers is marine euphotic zone primary production or subsequent heterotrophic consumption of this biomass. Two lipid classes represent exceptions to this finding. !J.14C values for the n-alkanes are consistent with mixed fossil and contemporary terrestrial plant sources.The archaeal isoprenoid data reflect chemoautotrophic growth below the euphotic zone.The biomarker class most clearly representing marine phytoplanktonic production is the sterols. It is suggested, therefore, that the sterols could serve as paleoceanographic tracers for surface-water DIC.The isotopic data are used to construct two algebraic models. The first calculates the contributions of fossil and modem vascular plant carbon to 5MB n-alkanes. This model indicates that the !J.14C of the modern component is +235%0 (post-bomb) or 0%0 (pre-bomb). The second model uses these values to determine the origin of sedimentary TOe. The results are comparable to estimates based on other approaches and suggest that -60% of 5MB TOC is of marine origin, modern terrestrial and fossil sources contribute -10% each, and the remaining -20% is of unknown origin.iii For all of our mothers.iv ACKNOWLEDGEMENTS

show abstract

Single Compound Radiocarbon Measurements

Eglinton¹,

Pearson²

2001

Encyclopedia of Ocean Sciences

View full text Add to dashboard Cite

High molecular weight (HMW) dissolved organic matter (DOM) in seawater : chemical structure, sources and cycling

Cited by 7 publications

References 63 publications

Characterization of extracellular polymers of Phaeocystis globosa and P. antarctica

Characterization of extracellular polymers of Phaeocystis globosa and P. antarctica

Biogeochemical applications of compound-specific radiocarbon analysis

Single Compound Radiocarbon Measurements

Contact Info

Product

Resources

About