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

氮营养的差异可能会影响浮游植物的分布，因为每种氮源具有不同的有效模式。铵是大多数浮游植物首选的氮源，但通常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重要的氮源。因为尿素和铵是在浮游生物体内产生的，而硝酸盐是由较深的水提供的，所以各种氮源的相对可用性在空间和时间上都是变化的。目前在培养的海洋蓝藻能够以铵或硝酸盐作为唯一的氮源生长，但只有大约一半的蓝藻能够利用尿素。这表明尿素可能会影响海洋蓝藻的生长速度和分布。该项目将开发蓝藻脲酶的分子探针，然后将用于实地研究，以检查蓝藻脲酶利用与基本海洋参数之间的关系。分子探针将被使用，因为任何其他技术都不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. ***