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.
