Measurement of Enzymatic Hydrolysis Rates of Organic Macromolecules in Seawater and Sediments: Development of a Technique Using FLA-Polysaccharides

小行星9503487 有机大分子矿化的速率以及降解速率随位置、深度和季节的变化是计算海洋有机碳周转率的关键方面。最近的研究表明，大型溶解聚合物，特别是多糖，可能会在海洋上层迅速循环。然而，目前很少有直接测量海洋环境中有机大分子水解的方法。该试验项目的目的是测试和应用一种新的方法来测量海洋环境中多糖的水解速率。 该方法是基于荧光标记的多糖（弗拉-多糖），可以添加到海水或沉积物的合成。 FLA-polysaccharides的酶促水解产生较低分子量的标记片段。用凝胶渗透色谱法测定了FLA-polysaccharide的分子量变化。最终结果是显示弗拉-多糖分子量随时间变化的曲线。

9503487 ARNOSTI The rates at which organic macromolecules are mineralized, and variations in degradation rates with location, depth, and season are critical aspects in calculating the turnover rates of oceanic organic carbon. Recent studies have suggested that large dissolved polymers, particularly polysaccharides, may be rapidly cycled within the upper ocean. There are currently few methods, however, to directly measure the hydrolysis of organic macromolecules in marine environments. The objective of this pilot project is to test and apply a new method to measure hydrolysis rates of polysaccharides in marine environments. The method is based on synthesis of fluorescent-labeled polysaccharides (FLA- polysaccharides) which can be added to seawater or sediments. Enzymatic hydrolysis of FLA-polysaccharides yields labeled fragments of lower molecular weight. The molecular weight changes of FLA-polysaccharide are determined using gel permeation chromatography. The end result is a profile showing changes in FLA- polysaccharides molecular weight vs. time.