Microbial Cell-Surface Phosphatases in Estuarine and CoastalMarine Ecosystems: Regulation and Role in Pi Regeneration

海洋初级生产者每年消耗的氮和磷总量的99%以上最终由再生提供。磷代谢特别依赖于正磷酸盐的快速再生，因为没有类似于固氮的生物磷输入过程。此外，磷再生（与氮再生不同）主要是细胞外过程。微生物细胞表面酶在Pi再生调节中的作用的调查将在实验室进行。海洋细菌的纯培养物将用于根据底物特异性和磷浓度的影响来区分两种酶，5 '-核苷酸酶和碱性磷酸酶。本文尝试用凝胶电泳法分离纯化这两种酶。这些研究将有助于阐明这两种微生物酶在磷再生和正磷酸盐循环中的潜在重要性，并为将来使用分子技术奠定基础。

Over 99% of the total nitrogen and phosphorus consumed each year by oceanic primary producers is ultimately supplied by regeneration. Phosphorus metabolism is particularly dependent on rapid regeneration of orthophosphate, since there is no biological phosphorus input process analogous to nitrogen fixation. Also, phosphorus regeneration (unlike nitrogen regeneration) is largely an extracellular process. An investigation of the role of microbial cell-surface enzymes in the regulation of Pi regeneration will be undertaken in the laboratory. Pure cultures of marine bacteria will be used to distinguish two enzymes, 5'-nucleotidase and alkaline phosphatase, on the basis of substrate specificity and the effect of phosphorus concentration. An attempt will be made to seperate and purify these two enzymes using gel electrophoresis. These studies should help clarify the potential importance of these two microbial enzymes in phosphorus regeneration and orthophosphate cycling, and set the stage for future use of molecular techniques.