Department of Microbiology and Institute of Ecology, University of Georgia, Athens, Georgia 30602.
Appl Environ Microbiol. 1991 Nov;57(11):3135-43. doi: 10.1128/aem.57.11.3135-3143.1991.
The sugar contents of emergent macrophytes from a freshwater lake, a freshwater swamp, and a salt marsh in the southeastern United States were examined together with the dissolved free sugars produced during macrophyte degradation and in natural water samples collected adjacent to macrophyte stands. Simultaneous separation of up to 13 neutral and 2 amino sugars together with 3 uronic acids and muramic acid was achieved by anion-exchange high-performance ion chromatography. As little as 10 pmol or a concentration of 20 nM sugar can be detected by pulsed amperometry, a greater sensitivity for sugar quantification than that of previously reported detection techniques used in conjunction with either gas or liquid chromatographic systems. Optimum conditions for hydrolysis of plant material by using trifluoroacetic acid were determined, and internal standards were used to quantify losses due to matrix effects and solid-phase extraction of samples. Our data demonstrate that ratios of certain indicator sugars in undegraded macrophytes differ significantly from ratios of dissolved free sugars formed during macrophyte degradation, reflecting the complex processes (biological and physical) involved in vascular plant degradation in aquatic ecosystems. Natural water samples collected adjacent to macrophyte beds contained dissolved free sugars at concentrations of 620 nM (lake), 890 nM (freshwater swamp), and 2,300 nM (salt marsh). Sugar signatures of these natural water samples were similar to those of macrophyte degradation products.
我们检测了美国东南部淡水湖、淡水沼泽和盐沼中水生大型植物的糖含量，以及水生大型植物降解过程中产生的溶解游离糖和在水生大型植物生长地附近采集的天然水样中的溶解游离糖。通过阴离子交换高效离子色谱法，最多可同时分离 13 种中性糖和 2 种氨基糖以及 3 种糖醛酸和 muramic 酸。采用脉冲安培检测法，检测灵敏度可达 10 pmol（浓度为 20 nM 糖），比以前报道的与气相或液相色谱系统联用的检测技术的检测灵敏度更高。我们还确定了使用三氟乙酸水解植物材料的最佳条件，并使用内标来量化由于基质效应和样品固相萃取造成的损失。我们的数据表明，未降解的水生大型植物中某些指示糖的比例与水生大型植物降解过程中形成的溶解游离糖的比例有显著差异，这反映了水生生态系统中维管束植物降解过程中涉及的复杂过程（生物和物理过程）。在水生大型植物生长地附近采集的天然水样中，溶解游离糖的浓度分别为 620 nM（湖泊）、890 nM（淡水沼泽）和 2300 nM（盐沼）。这些天然水样的糖特征与水生大型植物降解产物的糖特征相似。
