Production of chromophoric dissolved organic matter fluorescence in marine and estuarine environments: an investigation into the role of phytoplankton
Production of chromophoric dissolved organic matter fluorescence in marine and estuarine environments: an investigation into the role of phytoplankton
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DOI：
10.1016/s0304-4203(01)00072-x
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发表时间：
2002
期刊：
影响因子：
3
通讯作者：
E. Rochelle-Newall;T. Fisher
中科院分区：
文献类型：
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作者：
E. Rochelle-Newall;T. Fisher
我们测试了浮游植物是否是一个直接来源的发色溶解有机物（CDOM）的荧光在一系列的实验。在第一个实验中，超声处理的11个密集的藻类培养物从几个藻类类显示没有立即释放CDOM荧光。在第二个实验中，使用营养素添加生物测定从一系列的网站在大西洋中部地区，我们发现没有增加CDOM荧光营养限制时，尽管叶绿素a在3-5天内大幅增加缓解。在第三个实验中，在28天的时间内，在五个非纯藻类分批培养物中测量CDOM荧光的变化。CDOM荧光几乎没有增加，直到培养物进入稳定期，此时观察到CDOM荧光呈指数增加。在第四组实验中，在一系列中肋骨条藻和最小原甲藻的培养物中检查CDOM荧光的产生。在黑暗中，在没有自养生长的情况下，我们观察到CDOM荧光产生速率缓慢（0.02-0.05 NFlU第-1天）。在平行光照的培养物中（0.1-0.2 NFlu第-1天），发生率要高得多，但与细菌计数的相关性大于与藻类生物量的相关性。在该实验的第三阶段，当光照时，将固定相培养物通过1 μm孔径的过滤器过滤并在黑暗中孵育，CDOM荧光产生继续保持不变。这些结果是一致的假设，浮游植物是不是一个直接的来源，在海洋和河口环境中的CDOM荧光和CDOM荧光产生的细菌使用来自浮游植物的非荧光有机物。
We tested whether phytoplankton are a direct source of chromophoric dissolved organic matter (CDOM) fluorescence in a series of experiments. In the first experiment, sonication of 11 dense algal cultures from several algal classes revealed no immediate release of CDOM fluorescence. In a second experiment, using nutrient addition bioassays from a range of sites in the mid-Atlantic region, we found no increase in CDOM fluorescence when nutrient limitation was alleviated despite large increases in chlorophyll a over 3–5 days. In a third experiment, the change in CDOM fluorescence over a 28-day period in five non-axenic algal batch cultures was measured. There was little or no increase in CDOM fluorescence until the cultures entered the stationary phase, whereupon an exponential increase in CDOM fluorescence was observed. In a fourth set of experiments, the production of CDOM fluorescence was examined in a series of cultures of Skeletonema costatum and Prorocentrum minimum. In the dark, in the absence of autotrophic growth, we observed slow rates of CDOM fluorescence production (0.02–0.05 NFlU day−1). Rates were much higher in parallel lighted cultures (0.1–0.2 NFlU day−1) but were more related to bacterial counts than to algal biomass. In a third phase of this experiment, when illuminated, stationary phase cultures were filtered through 1-μm pore size filters and incubated in the dark, CDOM fluorescence production continued unchanged. These results are consistent with the hypothesis that phytoplankton are not a direct source of CDOM fluorescence in marine and estuarine environments and that CDOM fluorescence is produced by bacteria using non-fluorescent organic matter derived from phytoplankton.