C-DEBI Newsletter – April 15, 2015
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Hot off the press: Data report: dissolved and particulate organic carbon in the deep sediments of IODP Site U1363 near Grizzly Bare seamount (C-DEBI Contribution 236) in Proceedings of the IODP Volume 327
Authors: C-DEBI researchers Lin, Hsieh, Cowen and Rappé. Abstract: Marine sediments are a primary reservoir for the long-term storage of organic matter, and the rate of burial and oxidation of this sedimentary organic material help to regulate both atmospheric oxygen and carbon dioxide concentrations. To evaluate the impact of circulating basement fluid on the preservation of deeply buried organic carbon, sedimentary profiles of dissolved and particulate organic carbon (DOC and POC) near the sediment/basement interface were obtained from sediment coring at Site U1363 during Integrated Ocean Drilling Program Expedition 327. Sedimentary DOC increased from 0.25 mM at 1 m below the seawater/sediment interface to a maximum of 0.86 mM at mid-depth (8–11 meters below seafloor [mbsf]), before subsequently decreasing to a minimum of 0.10 mM at the sediment/basement interface (222.7 mbsf). Thus, the oceanic basement appears to be a net sink for sedimentary DOC. Sedimentary DOC and alkalinity profiles were similar and inversely mirror those of sulfate, suggesting that the buildup of DOC in sediment pore water is related to remineralization of sedimentary POC. The sedimentary POC content at Site U1363 ranged from 47 to 391 µmol-C/g, with δ13C values from –25.3‰ to –22.4‰. The total particulate nitrogen (PN) content ranged from 4.1 to 32.9 µmol-N/g, with δ15N values from 1.8‰ to 7.2‰ and a POC:PN ratio of 12 ± 2 (n = 54). No depth-specific systematic variations in POC, PN, POC:PN ratio, δ13C-POC or δ15N-PN were detected, and no significant correlations between sedimentary DOC and POC concentrations were observed.

Hot off the press: Catabolic rates, population sizes and doubling/replacement times of microorganisms in natural settings (C-DEBI contribution 234) in American Journal of Science
Authors: C-DEBI researcher LaRowe and director Amend. Abstract: Directly assessing the impact of subsurface microbial activity on global element cycles is complicated by the inaccessibility of most deep biospheres and the difficulty of growing representative cultivars in the laboratory. In order to constrain the rates of biogeochemical processes in such settings, a quantitative relationship between rates of microbial catalysis, energy supply and demand and population size has been developed that complements the limited biogeochemical data describing subsurface environments. Within this formulation, rates of biomass change are determined as a function of the proportion of catabolic power that is converted into anabolism—either new microorganisms or the replacement of existing cell components—and the amount of energy that is required to synthesize biomass. Catabolic power is related to biomass through an energy-based yield coefficient that takes into account the constraints that different environments impose on biomolecule synthesis; this method is compared to other approaches for determining yield coefficients. Furthermore, so-called microbial maintenance energies that have been reported in the literature, which span many orders of magnitude, are reviewed. The equations developed in this study are used to demonstrate the interrelatedness of catabolic reaction rates, Gibbs energy of reaction, maintenance energy, biomass yield coefficients, microbial population sizes and doubling/replacement times. The number of microorganisms that can be supported by particular combinations of energy supply and demand is illustrated as a function of the catabolic rates in marine environments. Replacement/doubling times for various population sizes are shown as well. Finally, cell count and geochemical data describing two marine sedimentary environments in the South Pacific Gyre and the Peru Margin are used to constrain in situ metabolic and catabolic rates. The formulations developed in this study can be used to better define the limits and extent of life because they are valid for any metabolism under any set of conditions.

Frontiers in Microbiology: Seeking Contributions for Special Topic on Ocean Crust Geomicrobiology
A special issue of Frontiers in Microbiology journal on the topic of "Recent Advances in Geomicrobiology of the Ocean Crust" is seeking contributions from the C-DEBI community. Articles in the research topic are in tribute to the late Katrina J. Edwards, who was a pioneer in diverse aspects of exploring life in oceanic crust. For more information, contact topic editors Beth Orcutt, Cara Santelli, or Jason Sylvan, or visit the journal webpage. Abstracts due April 16, 2015.

Proposal Calls

IODP: Apply to sail on Expedition 364 Chicxulub Impact Crater
The deadline to apply is May 08, 2015. To learn more about the scientific objectives of this expedition, life at sea, and how to apply to sail, please join the ECORD Science Operator for a web-based seminar on Tuesday, April 21, 2015 at 9am EDT. To register, please visit:

DCO: Deep Life Community Call for Proposals 
Application deadline: May 01, 2015.

National Academies: Research Associateships for Graduate, Postdoctoral and Senior Researchers
There are four annual review cycles and the next closes May 01, 2015.

IODP-USSSP: Proposals for Pre-Drilling Activities and Workshops
The U.S. Science Support Program (USSSP) accepts proposals on a rolling basis for pre-drilling activities and semi-annually for workshops, next submission deadline May 15, 2015, related to the International Ocean Discovery Program (IODP).

DCO: Call for Proposals Census of Deep Life Sequencing Opportunities
Application deadline: June 01, 2015.

Education & Outreach

Meetings, Workshops and Activities

DCO: Second DCO Early Career Scientist Workshop, August 31 - September 5, 2015, São Miguel, Portugal
Applications are encouraged from senior graduate students, postdoctoral researchers, fellows, and newly appointed assistant professors, due May 01, 2015.

Gordon Research Seminar on Applied and Environmental Microbiology: Solving Important Microbiological Questions in the "Omics" Era; July 11-12, Mt. Holyoke College, South Hadley, MA
Deadline for oral abstracts is closed. Meeting application due June 13, 2015.


C-DEBI: Education, Outreach, and Diversity Manager
The Center for Dark Energy Biosphere Investigations (C-DEBI) is seeking a Program Manager to join its team. C-DEBI is a multi-institutional research and education center funded by the National Science Foundation with USC as its headquarters. In addition to the science of exploring microbial life beneath the seafloor, education and diversity are priorities to the Center's efforts to strengthen the STEM pipeline by integrating research and educational programs for diverse future generations. The full-time Program Manager will serve as Education, Outreach, and Diversity Manager, helping to create, coordinate, and lead our education, outreach, and diversity efforts to serve our students, postdocs, faculty, and other participants at USC and across the nation. The Program Manager will also direct day-to-day project operations and administrative activities of C-DEBI at USC. The ideal candidate for the position of C-DEBI Education, Outreach, and Diversity Manager has:

  • 5 years of experience developing and managing educational STEM programs with multiple institutions
  • Leadership and strong oral and written communication skills
  • Experience using social media for professional outreach
  • Research experience at Ph.D. level

See the USC jobs website for more information on this posting ID 1003195:

Texas A&M, College Station: Postdoctoral research associate, Microbiology/Molecular Biology
The position will be filled as soon as possible, but by July 2015 at the latest.

MBARI: Principle Investigator
The Monterey Bay Aquarium Research Institute (MBARI) seeks a Principal Investigator (PI) to develop and direct a marine carbon cycle research team.

Bermuda Institute of Ocean Sciences: Chemical/Physical/Biological Oceanographer
Review of applications will begin April 15, 2015.

UTK: Professor and Head Department of Microbiology, The College of Arts & Sciences
Review of applications will begin on March 31, 2015 and will continue until the position is filled.

University of Nevada, Las Vegas: Postdoctoral Fellow in microbiology (“microbial dark matter” biology)
The review of materials will begin December 01, 2014, and will continue until the position is filled.

Skidaway Institute of Oceanography: Two Tenure Track Faculty Positions in Oceanography
The committee will begin to review applications on October 24, 014 and will continue until the positions are filled.

Don’t forget to email me with any items you'd like to share in future newsletters! You are what makes our deep biosphere community!
Matthew Janicak
Data Manager
Center for Dark Energy Biosphere Investigations (C-DEBI)
University of Southern California
3616 Trousdale Pkwy, AHF 209, Los Angeles, CA 90089-0371
Phone: 708-691-9563, Fax: 213-740-2437

Exploring life beneath the seafloor and making transformative discoveries that advance science, benefit society, and inspire people of all ages and origins.

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