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Transformation of bio-polymers into dissolved and colloidal organic matters in the ocean

将生物聚合物转化为海洋中溶解的和胶体的有机物

基本信息

批准号：
11304039
负责人：
KOIKE Isao
金额：
$ 19.1万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

In the ocean, biochemical characters of bio-polymers produced by various planktonic assemblages are modified through the interaction with microbes and abiotic processes such as UV-radiation, and are believed to obtain their refractory characters. At the same time, aggregation of modified bio-polymeis into suspended or settling particle size would occur. In this project, fate of bio-polymers in the upper layer of the ocean was chased through extensive field process studies together with simple model experiments in the laboratory. One of the focus of the project is to determine biological and physico-chemical factors controlling aggregation of colloidal and submicron organic particles into large aggregates having enough settling velocities. Following findings and interpretation were obtained from this project. 1) Determination of submicron sized TEP concentration in environmental gradient from coastal waters to oligotrophic open waters prevailed that, irrespective of the depth and areas, … More some 70-80% of total TEP concentrations were located in the submicron-sized fraction, suggesting importance of colloidal sized TEP to form TEP of suspended dimension. 2) Production of semi-refractory organic carbon and nitrogen through microbial uptake and subsequent metabolisms of simple organic matters such as amino acids and glucose was observed within 10-15 days. There is striking similarities of biochemical characters between those freshly formed semi-refractory organic matters and those obtained in open ocean samples, suggesting that microbial processes are a possible factor for the formation of semi-refractory organic matters in the ocean.. 3) Significant contribution of attached micro-flagellates on the aggregation of submicron particles into large aggregates in the upper ocean. The above possibility was tested by an experimental approach using artificial submicron particles, and we obtained significant stimulation of aggregation processes by feeding current of attached microflagellates at least in coastal marine environments. 4) Detection of 100-150 micron sized aggregates within thermocline of coastal waters, sensed by in situ particle size counter. Using a newly developed sensor, clear difference of size distribution of suspended particles between in the mixing layer and within theirmocline was observed, which is direct evidence of active aggregation processes in the upper water column. Less

在海洋中，各种浮游生物组合产生的生物聚合物的生化特性通过与微生物和非生物过程（例如紫外线辐射）的相互作用而改变，并且被认为获得了其难熔特性。同时，改性生物聚合物会聚集成悬浮或沉降的颗粒尺寸。在该项目中，通过广泛的现场过程研究以及实验室的简单模型实验，追踪了海洋上层生物聚合物的命运。该项目的重点之一是确定控制胶体和亚微米有机颗粒聚集成具有足够沉降速度的大聚集体的生物和物理化学因素。从该项目中获得了以下发现和解释。 1) 从沿海水域到贫营养开放水域的环境梯度中亚微米级 TEP 浓度的测定普遍表明，无论深度和面积如何，总 TEP 浓度的约 70-80% 位于亚微米级部分，这表明胶体级 TEP 对形成悬浮尺寸的 TEP 的重要性。 2）在10-15天内观察到通过微生物摄取和随后的氨基酸和葡萄糖等简单有机物的代谢产生半耐火有机碳和氮。这些新形成的半难熔有机物与在开放海洋样品中获得的生物化学特征存在惊人的相似性，这表明微生物过程是海洋中半难熔有机物形成的可能因素。3）附着的微鞭毛虫对上层海洋中亚微米颗粒聚集成大聚集体的显着贡献。通过使用人造亚微米颗粒的实验方法测试了上述可能性，并且至少在沿海海洋环境中，我们通过附着的微鞭毛虫的馈送流获得了对聚集过程的显着刺激。 4) 检测沿海水域温跃层内 100-150 微米大小的聚集体，通过原位粒度计数器感测。使用新开发的传感器，可以观察到混合层和斜层内悬浮颗粒尺寸分布的明显差异，这是上部水柱中活跃聚集过程的直接证据。较少的