Release of fixed N2 and C as dissolved compounds by Trichodesmium erythreum and Nodularia spumigena under the influence of high light and high nutrient (P)
Release of fixed N2 and C as dissolved compounds by Trichodesmium erythreum and Nodularia spumigena under the influence of high light and high nutrient (P)
复制标题
在高光和高营养的影响下，红木霉和海绵球藻以溶解化合物形式释放固定的 N2 和 C（P）
DOI：
10.3354/ame01343
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发表时间：
2009
影响因子：
1.4
通讯作者：
M. Voss
中科院分区：
文献类型：
--
作者：
N. Wannicke;B. Koch;M. Voss
测定了赤藓和生泡节球藻固氮和固碳速率的昼夜变化以及随后的总溶解氮（TDN）和溶解有机碳（DOC）释放量。观察到N2和C固定的昼夜节律，以及溶解化合物的计算释放的周期性。从T.在光照条件下，刺桐的TDN和DOC释放量分别为71%和50%，N.我们发现在光照期间，spumigena的释放分别为89%和53%。此外，还研究了光照和营养盐浓度对TDN和DOC释放的影响。这些数据表明，向更高的光强度的快速转变导致了显著的TDN和DOC渗出。在短期基础上（暴露后的前30 min），NH 4+和DON的渗出消耗了瓦尔间相同时间内细胞收集的高达52%的电子。因此，TDN释放作为一个潜在的电子汇，保护细胞免受光破坏。磷浓度对TDN和DOC的释放影响不明显。我们的研究结果表明，TDN和DOC的吸收和随后的分泌可能是由非生物参数诱导，除了由多个反馈回路的内源性调节。
Diel variations of N2 and C fixation rates, as well as subsequent release of total dissolved N (TDN) and dissolved organic carbon (DOC) were determined for Trichodemsium erythreum and Nodularia spumigena. A circadian rhythm of N2 and C fixation, as well as a periodicity in the calcu- lated release of dissolved compounds, was observed. From the amounts of N and inorganic C fixed by T. erythreum during the light period of the experiment, 71 and 50% were released as TDN and DOC, respectively; for N. spumigena we found a release of 89 and 53%, respectively, during the light period. Additionally, 2 controlling factors (light and nutrient concentrations) for the release of TDN and DOC were studied. The data suggest that rapid shifts towards higher light intensity lead to a pro- nounced exudation of TDN and DOC. On a short-term basis (first 30 min after exposure), the exuda- tion of NH4 + and DON consumed up to 52% of electrons harvested by the cells in the same time inter- val. Thus TDN release serves as a potential electron sink and protects cells from photodestruction. On the other hand, there was no clear effect of phosphorus concentration on the release of TDN and DOC. Our results indicate that uptake and subsequent exudation of TDN and DOC might be induced by abiotic parameters, besides being regulated endogenously by multiple feedback loops.