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C fix'n by Riftia
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2015
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Atlantis
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Project Title: |
COLLABORATIVE RESEARCH: Environmental and internal influences on the activities of the Calvin- and reductive citric acid cycles in hydrothermal vent symbiosis Riftia pachyptila |
Project Status: |
Submitted |
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Principal Investigator: |
Kathleen Scott, USF_Tampa |
Project Institution: |
USF_Tampa |
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Project ID: |
103490 |
Version #: |
4 |
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Date Submitted: |
8/1/2012 3:58:00 PM |
Created By: |
Kathleen Scott |
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Date Last Modified: |
6/5/2014 9:56:00 AM |
URI Serial #: |
None |
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Funding Agencies: |
NSF/BIO/IOS - 1257532 - Funded |
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Summary of Field Work: |
We are requesting two research cruises (2013 and 2014) to the 9° North Integrated Study Site to collect Riftia pachyptila tubeworms for shipboard experiments to elucidate the pathway of carbon fixation by their chemolithoautotrophic symbionts. Below is our project summary:
PROJECT SUMMARY
Intellectual merit
All life on Earth depends upon the fixation of carbon dioxide to organic carbon by photo- and chemosynthetic macro- and microorganisms. There are four known pathways that catalyze this process. Based on phylogenetic distributions and functional attributes, it has been posited that the Calvin Benson Bassham cycle dominates in aerobic terrestrial and marine aerobic habitats due to its resilience to oxygen, while other “oxygen sensitive” carbon fixation pathways are relegated to hypoxic or anoxic environs like vents and hot springs.
Contrary to this supposition, there are chemoautotrophic symbioses found in hypoxic diffuse flows around hydrothermal vents that use the Calvin Benson Bassham cycle. Vestimentiferan tubeworm-bacterial symbioses, in particular Riftia pachyptila (‘Riftia’), are the dominant keystone species at hydrothermal vents in the Pacific Ocean. These symbiotic systems fix carbon at mass specific rates comparable to the fastest growing photoautotrophs. Surprisingly, recent studies suggest that the symbionts possess and express two carbon fixation pathways, the Calvin Benson Bassham cycle and the reductive tricarboxylic acid cycle. The use of these two pathways by a single organism (the symbiont) to fix carbon is unprecedented, and may represent an evolved strategy to cope with the high variability in environmental conditions encountered by hydrothermal vent organisms.
Here we propose to interrogate carbon fixation by Riftia in conditions that mimic the environmental variations found in situ. Overall, we propose to quantify the relationship between metabolic activity (substrate uptake and mass-balance analyses), pathway flux (metabolite quantification), and enzyme activity to understand how these factors sustain carbon fixation in a dynamic environment. These data will considerably further our understanding of carbon fixation by chemoautotrophic microorganisms, and will represent the most significant physiological and biochemical interrogation of any deep-sea organism or chemoautotrophic symbiosis to date.
Broader impacts
We are equally committed to the proposed scientific research and our proposed education and outreach. We plan to support three major programs: (1) graduate student development (2) undergraduate mentoring, and (3) the design of high-impact educational curricula using real research data and experiences. This study will enable the support and training of undergraduate and graduate students who will be intimately involved in designing and engineering the experiments, analyzing the data, and formally presenting and documenting the work. The proposed research contains significant field and laboratory components, which affords students and teachers the opportunities to participate in this project at a variety of levels.
This proposal is a resubmission of a full proposal that was very favorably reviewed but denied funding due to concerns about previously proposed proteomic analyses and dynamic modeling. In response to the reviews, these aspects have been removed and replaced with more robust approaches to addressing these hypotheses, including enzyme assays diagnostic for the two metabolic pathways under consideration, enhanced respirometric approaches, metabolomic analyses and steady-state mass balance modelling. |
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Summary of Facility Requirements: |
We will need approximately 10 collections of Riftia per cruise, with temperature data collected with the specima.
Cruise duration: In order to undertake the shipboard analyses of these 10 collections (respirometry and symbiont incubations) it would be best for each cruise to last 3 weeks.
DSRV preference: Due to the necessity for careful habitat characterization before specima collection, the necessity to prevent injury to Riftia during collection, and the necessity for sample retrieval as soon as possible after Riftia collection, we feel it best for ALVIN to be used for these collections. |
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Summary of other requirements and comments: |
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Type of Request: |
Collaborative Ship Use |
Request Status: |
Submitted |
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Request ID: |
1005520 |
Created By: |
Kathleen Scott |
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Date Last Modified: |
6/5/2014 9:13:00 AM |
Date Submitted: |
8/1/2012 3:58:00 PM |
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Year: |
2015
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Ship/Facility: |
Atlantis
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Optimum Start Date:
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8/1/2015 |
Dates to Avoid: |
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Earliest Start Date: |
8/1/2015 |
Multi-Ship Op: |
No |
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Latest Start Date: |
12/31/2015 |
Other Ship(s): |
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Operating Days Needed: |
Science Days |
Mob Days |
De-Mob Days |
Estimated Transit Days |
Total Days |
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2 |
0 |
0 |
0 |
2 |
Repeating Cruise?
(within same year) |
No |
Interval: |
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# of Cruises: |
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Description of Repeating cruise requirements: |
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Justification/Explanation for ship choice, dates,
conflicts, number of days & multi-ship operations: |
We are requesting two research cruises (2014 and 2015) to the 9° North Integrated Study Site to collect Riftia pachyptila tubeworms for shipboard experiments to elucidate the pathway of carbon fixation by their chemolithoautotrophic symbionts.
We will need approximately 10 collections of Riftia per cruise, with temperature data collected with the specima.
Cruise duration: In order to undertake the shipboard analyses of these 10 collections (respirometry and symbiont incubations) it would be best for each cruise to last 3 weeks.
DSRV preference: Due to the necessity for careful habitat characterization before specima collection, the necessity to prevent injury to Riftia during collection, and the necessity for sample retrieval as soon as possible after Riftia collection, we feel it best for ALVIN to be used for these collections. |
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Short Description of Op Area
for use in schedules: |
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| Description of Op Area: |
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| Op Area Size/Dia.: |
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Lat/Long |
Marsden Grid |
Navy Op Area |
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Beginning
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Ending
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Show Degrees Minutes |
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Foreign Clearance Required? |
No |
Coastal States:
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 Important Info on Foreign Research Clearances
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Are you or any member in your science party bringing in any science equipment items which are regulated for export by the International Traffic in Arms Regulations (ITAR) and/or the Export Administration Regulations (EAR)?
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No |
If yes, have you applied for the necessary permits through your export control office?
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No |
| Questions about ITAR/EAR regulations?
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Comments about foreign clearance requirements or
description of any other special permitting requirements
(e.g., MMPA, ESA, IHA, Marine Sanctuaries, etc.) |
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Requested Start Port |
Intermediate Port(s) |
Requested End Port |
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Manzanillo, Mexico |
None |
Manzanillo, Mexico |
Explanation/justification for requested
ports and dates of intermediate stops
or to list additional port stops |
Manzanillo is near our study site and minimizes our transit times. |
Important Info on Working in Foreign Ports
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Chief Scientist: |
Kathleen Scott, USF_Tampa |
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# in Science Party |
5 |
# of different science teams |
2 |
# Marine Technicians to be
provided by ship operator:
(include in science party total)
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1 |
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Explanation of Science Party Requirements and Technician Requirements |
The PI and co-PI for this project would each like to bring a graduate student to assist with the sample analyses at sea. |
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 Dynamic Positioning | ADCP | Multibeam | Seismic |
| Dredging/Coring/Large Dia. Trawl Wire | Stern A-frame | Fiber Optic (.681) | 0.680 Coax Wire |
| SCUBA Diving |  Radioisotope use - briefly describe | NO Radioisotope use/Natural level work | Other Operator Provided Inst. - Describe |
| 0 PI-Provided Vans - briefly describe | MOCNESS | | |
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Explain Instrumentation or Capability
requirements that could affect choice
of ship in scheduling. |
14C-bicarbonate would be used in on-board, sealed incubations to track carbon fixation by bacterial endosymbionts from Riftia tubeworms. The PI has extensive experience with conducting these experiments at sea.
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Explain Major Ancillary Facilities
Requirements and list description
and provider for "other" systems. |
We would like to use ALVIN for this work.
Due to the necessity for careful habitat characterization before specima collection, the necessity to prevent injury to Riftia during collection, and the necessity for sample retrieval as soon as possible after Riftia collection, we feel it best for ALVIN to be used for these collections.
We will also be doing some 14C incubations critical for the work and the radioisotope van would facilitate this. |
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