A comparison of the chemical characteristics of oceanic DOM and extracellular DOM produced by marine algae
A comparison of the chemical characteristics of oceanic DOM and extracellular DOM produced by marine algae
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DOI：
10.3354/meps186105
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发表时间：
1999-01-01
影响因子：
2.5
通讯作者：
Repeta, DJ
中科院分区：
文献类型：
--
作者：
Aluwihare, LI;Repeta, DJ
比较了3种海洋浮游植物胞外高分子量溶解有机物（HMW DOM）与海水中HMW DOM的化学特征。海链藻、埃米利藻和棕囊藻，在事先经过超滤以去除高分子量溶解有机质的富营养海水中生长。在这些文化中产生的细胞外高分子量DOM分离超滤，其特征在于使用核磁共振（NMR）光谱，和分子水平的分析。所有物种都分泌富含多糖的DOM，而T. weissflocker和E. huxleyi密切类似酰基杂多糖（APS）以前确定为天然存在的海洋HMW DOM的主要成分。降解T. weissflocculus渗出物改变了DOM的化学组成，我们归因于特定多糖的反应性的差异。渗出液中最类似于海水DOM的组分相对于总多糖级分具有较慢的降解速率。我们的研究表明，从表层海洋中分离的APS可以有一个直接的藻类来源，APS可能会积累在海水中作为其代谢阻力的结果。
The chemical characteristics of extracellular high molecular weight (HMW) dissolved organic matter (DOM) from 3 species of marine phytoplankton were compared to HMW DOM in seawater. Thalassiosira weissflogii, Emiliania huxleyi and Phaeocystis sp., were grown in nutrient enriched seawater that had been previously ultrafiltered to remove HMW DOM. The extracellular HMW DOM produced in these cultures was isolated by ultrafiltration and characterized using nuclear magnetic resonance (NMR) spectroscopy, and molecular level analyses. All species exude DOM rich in polysaccharides, and the exudates of T. weissflogii and E. huxleyi closely resemble acyl heteropolysaccharides (APS) previously identified as major constituents of naturally occurring marine HMW DOM. Degradation of the T. weissflogii exudate alters the chemical composition of the DOM, which we attribute to differences in the reactivity of specific polysaccharides. The component within the exudate that most resembles seawater DOM has a slower degradation rate relative to the total polysaccharide fraction. Our study indicates that APS isolated from the surface ocean can have a direct algal source and that APS may accumulate in seawater as a result of its metabolic resistance.