Major biochemical composition of dissolved high molecular weight organic matter in seawater
- 標題
- Major biochemical composition of dissolved high molecular weight organic matter in seawater
- 作者
- Matthew McCarthy, John Hedges, Ronald Benner
- 文件屬性
- 國外期刊
- 知識分類
- 基礎研究
- 出版年
- 1996
- 刊名
- Marine Chemistry
- 點閱數
- 2604
摘要
Ultrafiltered dissolved organic matter (UDOM) was isolated from surface, oxygen minimum, and deep waters of three ocean basins and its elemental as well as molecular-level aldose and amino acid compositions were determined. Surface concentrations account for 23–33% of total dissolved organic carbon, and are a factor of 2–3 greater than those in deeper waters. Oceanic UDOM has an extremely characteristic organic composition, clearly distinct from other marine materials such as fresh plankton, sinking particles or humic substances. Polysaccharides appear to be the major reactive component of UDOM. They have a distinctive aldose distribution rich in galactose and deoxy sugar that is almost ubiquitous regardless of depth or location, suggesting that UDOM carbohydrate is dominated by a very similar suite of polysaccharide throughout the ocean. In contrast, amino acids account for a relatively minor component of both total UDOM and of its organic nitrogen component. Amino acid distributions are similar to those from unfractionated seawater, and are not preferentially remineralized.