Preservation of dissoloved organic matter in the Ocean

1. 最近的研究表明，来自细菌的有机聚合物在海水中积聚，然而，人们对这一巨大的溶解有机物池的动力学知之甚少。本研究考察了海水中溶解有机氮的主要成分肽聚糖的周转和转化。建立了一种从海洋细菌中分离纯化树突聚糖的新方法。成功制备了放射性标记肽聚糖。利用该材料，建立了一种检测天然海水中肽聚糖转化的新方法。在各种海洋环境中对肽聚糖降解的测量表明，肽聚糖的水解和摄取是不耦合的。测定了亚北极太平洋地区的外酶（肽酶和葡萄糖苷酶）活性。结果显示，在研究区域的东西轴线上，活动比的垂直剖面发生了戏剧性的变化。在中深海和深海环境中测定了细菌的生物量和活性。我们的研究结果表明，下沉颗粒在深海环境中被积极溶解，释放出溶解的胶体聚合物。开发了一个描述性模型来解释源自细菌的有机聚合物的释放和积累。

1. Recent studies have demonstrated that organic polymers derived from bacteria accumulate in seawater, yet the dynamics of this large pool of dissolved organic matter has been poorly understood. This study examined the turnover and transformation of peptidoglycan-a major constituent of dissolved organic nitrogen in oceanic waters.2. A new methodology was developed to isolate and purify paptidoglycan from marine bacteria.3. It was succeeded in preparing radio-labeled peptidoglycan. By using this material, a new assay technique was developed to examine turnover and transformation of peptidoglycan in natural seawater.4. The measurements of peptidoglycan degradation in a wide variety of marine environments demonstrated the uncoupling of hydrolysis and uptake of peptidoglycan.5. Ectoenzyme activities (peptidase and glucosidase) were determined in the subarctic Pacific. Results revealed a dramatic shift in the vertical profile of activity ratios along the east-west axis of the investigated region.6. Bacterial biomass and activity were determined in meso-and bathypalagic environments. Our results suggested that sinking particles are actively solubilized to release dissolved and colloidal polymers in deep oceanic environments.7. A descriptive model was developed to explain the release and accumulation of organic polymers derived from bacteria.