Comparison of the effects of water-soluble (EDTA) and particulate (Chelex-100) synthetic ligands on the growth of phytoplankton population in the disphotic zone seawater
Comparison of the effects of water-soluble (EDTA) and particulate (Chelex-100) synthetic ligands on the growth of phytoplankton population in the disphotic zone seawater
复制标题
水溶性（EDTA）和颗粒（Chelex-100）合成配体对弱光带海水中浮游植物种群生长影响的比较
DOI：
10.1007/bf02744378
复制
发表时间：
1998
影响因子：
2.3
通讯作者：
T. Nakashima
中科院分区：
文献类型：
--
作者：
Takayoshi Toyota;T. Nakashima
为了阐明天然有机配体对新上涌水中浮游植物生长的有利作用，进行了浮游植物养殖实验，以区分EDTA对某些有毒金属离子的解毒作用和增加必需金属的有效性。将EDTA和CHILEX-100分别或联合添加到去光区水样中，制成培养液。我们提出的工作假设是，通过使用CHILEX-100去除培养液中的有毒金属离子，以及通过EDTA对有毒金属离子进行解毒或增加必需金属的可用性，可以促进浮游植物的生长。添加了CHELEX-100和EDTA后，明显缩短了滞留期，提高了比种群增长率。与EDTA相比，EDTA的效果更为显著；在缩短滞后期方面，EDTA的效果为17%~44%，生长速度提高35%~56%。CHILEX-100对有毒金属离子的去除效果与EDTA解毒的效果相似，表明EDTA不仅具有解毒作用，还具有提高必需金属利用率的作用。目前的研究表明，Barber和Ryther(1969)在新上涌水中观察到的低生产力可以归因于有毒金属离子和缺乏有效形式的必需金属，因为它们的游离天然有机配体含量很低。
To clarify the beneficial roles of naturally occurring organic ligands on the growth of phytoplankton in newly upwelled water, phytoplankton culture experiments using disphotic zone water were conducted to discriminate between the effects of EDTA in the detoxification of certain toxic metal ions and increasing the availability of essential metals. Culture media were prepared by adding EDTA and Chelex-100, separately or in combination, to disphotic zone water samples. Our proposed working hypothesis is that phytoplankton growth can be enhanced by removing toxic metal ions from culture media by Chelex-100 and by detoxification of toxic metal ions or increasing the availability of essential metals by EDTA. A shortening of the lag period and an increase of the specific population growth rate were clearly observed after the addition of Chelex-100; nd EDTA. The effects of EDTA were more considerable than those of Chelex-100; a 17 to 44% in shortening the lag period and a 35 to 56% increase in the growth rate, when comparing the effects of Chelex-100 with those of EDTA. The similar effects of removing toxic metal ion by Chelex-100 as those of detoxification by EDTA suggested that EDTA has a role not only of detoxification but also of increasing the availability of essential metals. The present study suggests that the low productivity in newly upwelled water observed by Barber and Ryther (1969) can be ascribed to both toxic metal ions and a lack of available forms of essential metals because of their low contents of free natural organic ligands.