海洋浮游植物生长过程中溶解有机物质的三维荧光光谱研究

利用三维激发-发射矩阵荧光光谱技术,监测了赤潮异弯藻和中肋骨条藻培养过程中产生的溶解有机物,分析了三维荧光光谱图中的荧光峰位置、数量及荧光强度的变化情况.结果表明,微藻生长过程中会产生类蛋白和类腐殖质两类荧光有机物质,这两类有机物的荧光峰的位置及荧光强度有较大差异.在不同生长期,两类荧光有机物的产生机制不同.在指数生长期,两类有机物的荧光强度与藻密度成正相关,说明浮游植物释放了一定量的荧光物质;在平稳期和衰亡期,两类有机物的荧光强度迅速增加,这可能由于衰老、死亡藻细胞的破碎释放出大量的荧光有机物质所致,此外细菌对非荧光有机物进一步降解,也可能是产生该现象的一个原因.

Research on fluorescence excitation and emission matrix spectra of dissolved organic matter in phytoplankton growth process

The three-dimensional fluorescence excitation-emission matrix spectrum was used to detect the changes of dissolved organic substances from the cultured Heterosigma akashiwo and Skeletonema costatum. The peak, peak number and intensity of fluorescence in the spectra plots were analyzed. It is showed that two kinds of fluorescence dissolved organic substances, protein-like and humic-like, appeared during the algal growth process. The peaks and intensities of proteinlike and humic-like fluorescence were not consistent with the two algal biomasses from the culturing. The mechanisms of yielding the two kinds of fluorescence were different in each growth stage, and the contributions of phytoplankton to the fluorescence were also different. In the exponential phase, the positive relationships between the protein-like, humic-like fluorescence intensities and cell densities were observed. It implied phytoplankton released some fluorescence substances into water solution. In the stationary and decadency phases, the protein-like and humic-like fluorescence intensities increased quickly, which suggested that the two kinds of fluorescence were produced by the broken algal cells and the degradation of non-fluorescence organic substances derived by marine bacteria.