Design and Characterization of Cyanobacterial Bioreporters to measure Nutrient Availability in Marine Systems

几十年来，我们对水生生态系统中营养物质有效性的认识主要是通过对溶解元素的化学测量来获得的。虽然提供了一个合理的代理，但它告诉我们的营养物质生物利用度很少，这一特征特别适用于营养微量金属，如铁（Fe），但也与磷(P)等宏量营养素有关。区分一种营养物质的生物可利用形式和难降解形式经常被海洋学界认为是特别具有挑战性的。在这个项目中，鲍灵格林州立大学的研究人员将继续开发和表征发光蓝藻生物报告器，以提供对天然水体养分生物利用度的快速评估。在他们之前由美国国家科学基金会赞助的研究中，他们证明了这种方法在确定淡水系统中铁可用性方面的有效性。现在，他们将采用一种平行的方法来评估海洋系统中的养分可用性。他们最近成功开发了一种发光的全细胞蓝藻生物报告器，用于测量不同海洋环境中铁的可用性（Boyanapalli et al. 2007），这为概念提供了重要的证明。他们现在希望将生物记录器的使用范围扩大到海洋环境。该项目将重点开发铁和磷响应的蓝藻生物报告。承认普遍认识到铁的分布和可得性在水产生产方面具有重要意义，特别是与？高营养，低叶绿素？（HNLC）区域，他们将构建一系列互补的铁响应生物报告器，能够感知广泛的生物可利用铁。同样，他们计划构建具有区分生物可利用DIP和DOP种类的p响应生物报告器。尽管磷限制是现代湖沼学的核心原则，但直到最近才在海洋学家中得到更广泛的关注。然而，表面磷含量低与世界上大部分海洋有关。特别是，北大西洋西部地区和地中海一样，p值是有限的。该提案的一个实地组成部分涉及参加马尾藻海的机会巡航。就更广泛的影响而言，该项目将以特殊的教育外展为特色。自2004年以来，BGSU一直通过创新的大学伙伴关系（UP）计划与洛雷恩县社区学院（LCCC）建立伙伴关系。UP的创建是为了向Lorain及其周边县的居民提供服务，这些县构成了俄亥俄州的一部分。美国经济萧条？铁锈地带?，有机会在LCCC就读期间获得学士学位。通过UP， BGSU等机构通过远程学习提供教师和课程，以增加LCCC的课程设置。为了促进研究，LCCC的学生将与BGSU的教师联合顾问配对，该顾问将与LCCC的同行合作，以便学生可以使用LCCC的实验室设施进行他/她的项目。

For decades, our ideas on nutrient availability in aquatic ecosystems have been informed largely by chemical measurement of dissolved elements. While providing a reasonable proxy, it tells us little about nutrient bioavailability, a feature particularly applicable to nutritive trace metals such as iron (Fe) but also relevant to macronutrients like phosphorus (P). Distinguishing between biologically available and refractory forms of a nutrient is often cited as particularly challenging by the oceanographic community.In this project, researchers at Bowling Green State University will continue the development and characterization of luminescent cyanobacterial bioreporters to offer a rapid assessment of nutrient bioavailability from natural waters. In their previous NSF-sponsored research, they demonstrated the efficacy of this approach toward determining Fe availability in freshwater systems. Now, they will apply a parallel approach to assess nutrient availability in marine systems. Their recent success in developing a luminescent whole-cell cyanobacterial bioreporter for measuring Fe availability in diverse marine environments (Boyanapalli et al. 2007) has provided important proof of concept. They now hope to expand the use of bioreporters to the ocean milieu. The project will focus on the development of Fe- and P-responsive cyanobacterial bioreporters. Acknowledging widespread recognition that Fe distribution and availability is significant in terms of aquatic production, especially associated with ?high nutrient, low chlorophyll? (HNLC) regions of the ocean, they will construct a series of complementary Fe-responsive bioreporters capable of sensing a broad range of bioavailable Fe. Similarly, they plan to construct P-responsive bioreporters having the ability to discriminate between species of bioavailable DIP and DOP. Whereas P limitation is a central tenet of modern day limnology, it has only recently been afforded more widespread attention among oceanographers. Yet, low surface levels of P are associated with much of the world oceans. In particular, the western regions of the North Atlantic Ocean are P-limited as is the Mediterranean Sea. A field component of this proposal involves participation on a cruise of opportunity in the Sargasso Sea. . In terms of broader impacts, the project will feature a special educational outreach . Since 2004, BGSU has been involved in a partnership with Lorain County Community College (LCCC) through their innovative University Partnership (UP) program. The UP was created to provide the residents of Lorain and surrounding counties, which form part of Ohio?s economically-depressed ?rust belt?, an opportunity to receive bachelors degrees while attending LCCC. Through the UP, institutions such as BGSU provide faculty and curriculum to augment course offerings at LCCC through distance learning. To facilitate research, LCCC students will be paired with a BGSU faculty co-advisor who works with a counterpart at LCCC so that the student can conduct his/her project using LCCC lab facilities.