Project: Collaborative Research: Underexplored Connections between Nitrogen and Trace Metal Cycling in Oxygen Minimum Zones Mediated by Metalloenzyme Inventories

Acronym/Short Name:CliOMZ
Project Duration:2019-11 - 2025-10
Geolocation:Eastern Tropical Pacific

Description

NSF abstract:
Though scarce and largely insoluble, trace metals are key components of sophisticated enzymes (protein molecules that speed up biochemical reactions) involved in biogeochemical cycles in the dark ocean (below 1000m). For example, metalloenzymes are involved in nearly every reaction in the nitrogen cycle. Yet, despite direct connections between trace metal and nitrogen cycles, the relationship between trace metal distributions and biological nitrogen cycling processes in the dark ocean have rarely been explored, likely due to the technical challenges associated with their study. Availability of the autonomous underwater vehicle (AUV) Clio, a sampling platform capable of collecting high-resolution vertical profile samples for biochemical and microbial measurements by large volume filtration of microbial particulate material, has overcome this challenge. Thus, this research project plans an interdisciplinary chemistry, biology, and engineering effort to test the hypothesis that certain chemical reactions, such as nitrite oxidation, could become limited by metal availability within the upper mesopelagic and that trace metal demands for nitrite-oxidizing bacteria may be increased under low oxygen conditions. Broader impacts of this study include the continued development and application of the Clio Biogeochemical AUV as a community resource by developing and testing its high-resolution and adaptive sampling capabilities. In addition, metaproteomic data will be deposited into the recently launched Ocean Protein Portal to allow oceanographers and the metals in biology community to examine the distribution of proteins and metalloenzymes in the ocean. Undergraduate students will be supported by this project at all three institutions, with an effort to recruit minority students. The proposed research will also be synergistic with the goals of early community-building efforts for a potential global scale microbial biogeochemistry program modeled after the success of the GEOTRACES program, provisionally called "Biogeoscapes: Ocean metabolism and nutrient cycles on a changing planet".

The proposed research project will test the following three hypotheses: (1) the microbial metalloenzyme distribution of the mesopelagic is spatially dynamic in response to environmental gradients in oxygen and trace metals, (2) nitrite oxidation in the Eastern Tropical Pacific Ocean can be limited by iron availability in the upper mesopelagic through an inability to complete biosynthesis of the microbial protein nitrite oxidoreductase, and (3) nitrite-oxidizing bacteria increase their metalloenzyme requirements at low oxygen, impacting the distribution of both dissolved and particulate metals within oxygen minimum zones. One of the challenges to characterizing the biogeochemistry of the mesopelagic ocean is an inability to effectively sample it. As a sampling platform, we will use the novel biogeochemical AUV Clio that enables high-resolution vertical profile samples for biochemical and microbial measurements by large volume filtration of microbial particulate material on a research expedition in the Eastern Tropical Pacific Ocean. Specific research activities will be orchestrated to test the hypotheses. Hypothesis 1 will be explored by comparison of hydrographic, microbial distributions, dissolved and particulate metal data, and metaproteomic results with profile samples collected by Clio. Hypothesis 2 will be tested by incubation experiments using 15NO2- oxidation rates on Clio-collected incubation samples. Hypothesis 3 will be tested by dividing targeted nitrite oxidoreductase protein copies by qPCR (quantitative polymerase chain reaction)-based nitrite oxidizing bacteria abundance (NOB) to determine if cellular copy number varies with oxygen distributions, and by metalloproteomic analyses of NOB cultures. The demonstration of trace metal limitation of remineralization processes, not just primary production, would transform our understanding of the role of metals in biogeochemical cycling and provide new ways with which to interpret sectional data of dissolved and particulate trace metal distributions in the ocean. The idea that oxygen may play a previously underappreciated role in controlling trace metals due not just to metals' physical chemistry, but also from changing biological demand, will improve our ability to predict trace metal distributions in the face of decreasing ocean oxygen content.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.


DatasetLatest Version DateCurrent State
2025-01-14Preliminary and in progress
Dark DIC Fixation Rates collected from CliOMZ AT50-10 in the Eastern Pacific Ocean from May to June 2023 (CliOMZ project)2025-01-13Preliminary and in progress
Heterotrophic Production Rates collected from CliOMZ AT50-10 in the Eastern Pacific Ocean from May to June 2023 (CliOMZ project)2025-01-13Preliminary and in progress
Processed first profiles of sensor data from AUV Clio taken on R/V Atlantis (CliOMZ AT50-10 expedition) from Golfito Costa Rica to San Diego USA in May-June 2023.2024-09-09Final no updates expected
Summaries of tigerclaw and bushbaby tracers from AUV Clio taken on R/V Atlantis (CliOMZ AT50-10 expedition) from Golfito Costa Rica to San Diego USA in May-June 2023.2024-09-09Final no updates expected
Raw Sensor files from AUV Clio taken on R/V Atlantis (CliOMZ AT50-10 expedition) from Golfito Costa Rica to San Diego USA in May-June 2023.2024-09-09Final no updates expected
Log file from AUV Clio taken on R/V Atlantis (CliOMZ AT50-10 expedition) from Golfito Costa Rica to San Diego USA in May-June 2023.2024-09-09Final no updates expected
Trace metal rosette log of samples taken on board of the R/V Atlantis during the CliOMZ AT50-10 expedition from Golfito, Costa Rica to San Diego, USA that occurred in May - June of 2023.2024-06-13Final no updates expected
McLane pumps log deployed on the R/V Atlantis CliOMZ AT50-10 expedition from Golfito Costa Rica to San Diego USA that occurred in May - June of 2023. 2024-04-30Final no updates expected
Amended Rolling Deck to Repository (R2R) event log application (ELOG) taken on the R/V Atlantis CliOMZ AT50-10 expedition from Golfito Costa Rica to San Diego USA that occurred in May - June of 20232024-04-30Final no updates expected
Log for the samples taken using the Underway system on board of the R/V Atlantis during the CliOMZ AT50-10 expedition from Golfito, Costa Rica to San Diego, USA that occurred in May - June of 2023.2024-04-30Final no updates expected
Cellular carbon (C) and nitrogen (N) measurements of marine nitrifiers2022-03-11Final no updates expected
Dissolved inorganic carbon (DIC) fixation and dissolved organic carbon (DOC) release measurements of marine nitrifier cultures grown under different culture conditions2022-03-09Final no updates expected
Global proteome analyses of the nitrite-oxidizing bacterium Nitrospira marina grown under atmospheric and low oxygen concentrations2021-04-02Final no updates expected
Targeted proteome analyses of the nitrite-oxidizing bacterium Nitrospira marina grown under atmospheric and low oxygen concentrations2021-04-02Final no updates expected
Nitrite Oxidoreductase targeted metaproteomics from R/V Kilo Moana cruise KM1128 and R/V Falkor cruise FK160115 in the Central Pacific Ocean in 2011 and 20162020-04-21Final no updates expected
Whole cellular metal quotas, metal to phosphorous ratios, and metal to carbon ratios of Pseudoalteromonas sp. strain BB2-AT2 cultures originally collected from Scripps Pier, California coast in 19952020-04-20Preliminary and in progress
Cytosolic metallome data of the metalloproteome of Pseudoalteromonas sp. strain BB2-AT2 cultures originally collected from Scripps Pier, California coast in 19952020-04-08Preliminary and in progress
Metalloproteome protein data of the metalloproteome of Pseudoalteromonas sp. strain BB2-AT2 cultures originally collected from Scripps Pier, California coast in 19952020-04-08Data not available

People

Lead Principal Investigator: Mak A. Saito
Woods Hole Oceanographic Institution (WHOI)

Principal Investigator: John Breier
University of Texas Rio Grande Valley

Principal Investigator: Alyson E. Santoro
University of California-Santa Barbara (UCSB)

Co-Principal Investigator: Michael Jakuba
Woods Hole Oceanographic Institution (WHOI)

Contact: Mak A. Saito
Woods Hole Oceanographic Institution (WHOI)


Data Management Plan

Data Management Plan (82.54 KB)
12/04/2023