Marine Biotechnology Fellowship: Development of Molecular Tools for the Investigation of Urea Utilization by Marine Cyanobacteria in the Field

9321535由于每种氮源有不同的可利用模式，因此氮营养的科里尔差异可能会影响浮游植物的分布。铵是大多数浮游植物的首选氮源，但往往没有足够的量来支持浮游植物的生长。因此，尿素和硝酸盐是浮游植物的重要氮源。因为像铵一样的尿素是在浮游生物中产生的，而硝酸盐是从更深的水中供应的，各种氮源的相对有效性在空间和时间上都会发生变化。目前正在培养的海洋蓝藻能够以氨氮或硝酸盐作为唯一的氮源生长，但只有大约一半的海洋蓝藻能够利用尿素。这表明尿素可能影响海洋蓝藻的生长速度和分布。该项目将开发蓝藻尿素酶的分子探针，然后用于实地研究，以检查蓝藻尿素酶利用与基本海洋学参数之间的关系。将使用分子探针，因为任何其他技术都不太可能提供理解这些关系所需的灵敏度和分辨率。***

9321535 COLLIER Differences in nitrogen nutrition might affect the distribution of phyoplankters because each nitrogen source has different patterns of availability. Ammonium, which is the preferred nitrogen source of most phytoplankton, is often not available in sufficient quantities to support phytoplankton growth. Therefore urea and nitrate are important nitrogen sources for the phytoplankton. Because urea like ammonium is produced within the plankton, while nitrate is supplied from deeper water, the relative availability of the various nitrogen sources changes both in space and in time. Marine cyanobacteria currently in culture are able to grow with ammonium or nitrate as sole nitrogen source, but only about half of them are able to utilize urea. This suggest that urea may affect the growth rate and distribution of marine cyanobacteria. This project, will develop molecular probes to cyanobacterial ureases which will then be used in field studies to examine the relationships between cyanobacterial urease utilization and basic oceanographic parameter. Molecular probes will be used because it is unlikely that any other techniques can provide the sensitivity and resolution required to understand these relationships. ***