期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 102, 期 37, 页码 13023-13028出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.0506455102
关键词
marine biogeochemistry; nutrient limitation; phosphorus cycle
We show that the isotopic composition of oxygen (delta O-18) in dissolved inorganic phosphate (P-i) reveals the balance between P-i transport and biological turnover rates in marine ecosystems. Our delta(18)Op of P-i (delta(80)Op) measurements herein indicate the importance of cell lysis in the regeneration of P-i in the euphotic zone. Depth profiles of the delta(18)Op in the Atlantic and Pacific Oceans are near a temperature-dependent isotopic equilibrium with water. Small deviations from equilibrium below the thermocline suggest that P remineralization in the deep ocean is a byproduct of microbial carbon and energy requirements. However, isotope effects associated with phosphohydrolase enzymes involved in P remineralization are quite large and could potentially lead to significant disequilibration of P-i oxygen. The observed near equilibration of deep water P-i likely calls for continued slow rates of microbial uptake and release of P-i and/or extracellular pyrophosphatase-mediated oxygen exchange between water and P-i along the deep water flow path.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据