Nitrate Kinetics of Oceanic Ultraphytoplankters in Response to Transient Nanomolar Substrate Perturbations

向真光层提供的硝酸盐在海洋(因此也是全球)碳通量中起着关键作用。由于超浮游植物在这些水域占据主导地位，它们对硝酸盐的吸收可以说控制着这些过程。然而，现在人们认为，零星的硝酸盐脉冲提供了中央环流年总初级生产力的很大一部分，但超浮游植物对硝酸盐浓度的生态显著扰动的反应可能是海洋超浮游植物物种成功的一个因素。格洛弗和加赛德博士将使用化学发光方法表征超植物的海洋藻类和聚球藻克隆对生态意义上显著的(纳摩尔)硝酸盐增加的动力学反应。实验将包括测量硝酸盐限制的恒化器培养物的一个子样本上的硝酸盐吸收，这些培养物暴露在不同的硝酸盐浓度下，但与亲本培养物在相同的温度和光照条件下。他们的研究将有助于理解物理、化学和生理相互作用，这些相互作用综合在一起，调节以硝酸盐为基础的“新”生产，并最终作为二氧化碳汇控制海洋。

The nitrate supply to the euphotic layer plays a key role in oceanic (and therefore global) carbon fluxes. Since ultraphytoplankton dominate these waters, their nitrate uptake arguably controls these processes. However, it is now believed that episodic nitrate pulses provide a significant fraction of the total annual primary productivity in the central gyres, yet the response of ultraphytoplankters to ecologically significant nitrate perturbations in nitrate concentration is likely to be a factor in species success of oceanic ultraphytoplankters. Drs Glover and Garside will characterize the kinetic response of oceanic algal and Synechococcus clones of ultraphytoplanton to ecologically significant (Nanomolar) increases in nitrate, using the chemiluminescent method. Experiments will involve measuring nitrate uptake, on a subsample of a nitrate-limited chemostat culture, exposed to different nitrate concentrations, but under the same temperature and light conditions as the parent culture. Their studies will contribute to understanding physical, chemical and physiological interactions that integrate to mediate 'new' nitrate-based production and ultimately control the oceans as a CO2 sink.