C-DEBI Newsletter – February 15, 2019

Publications & Press

The ISME Journal
Carboxydotrophy potential of uncultivated Hydrothermarchaeota from the subseafloor crustal biosphere – NEW!
Stephanie A. Carr*, Sean P. Jungbluth, Emiley A. Eloe-Fadrosh, Ramunas Stepanauskas, Tanja Woyke, Michael S. Rappé, Beth N. Orcutt*
*C-DEBI Contribution 451

The exploration of Earth’s terrestrial subsurface biosphere has led to the discovery of several new archaeal lineages of evolutionary significance. Similarly, the deep subseafloor crustal biosphere also harbors many unique, uncultured archaeal taxa, including those belonging to Candidatus Hydrothermarchaeota, formerly known as Marine Benthic Group-E. Recently, Hydrothermarchaeota was identified as an abundant lineage of Juan de Fuca Ridge flank crustal fluids, suggesting its adaptation to this extreme environment. Through the investigation of single-cell and metagenome-assembled genomes, we provide insight into the lineage’s evolutionary history and metabolic potential. Phylogenomic analysis reveals the Hydrothermarchaeota to be an early-branching archaeal phylum, branching between the superphylum DPANN, Euryarchaeota, and Asgard lineages. Hydrothermarchaeota genomes suggest a potential for dissimilative and assimilative carbon monoxide oxidation (carboxydotrophy), as well as sulfate and nitrate reduction. There is also a prevalence of chemotaxis and motility genes, indicating adaptive strategies for this nutrient-limited fluid-rock environment. These findings provide the first genomic interpretations of the Hydrothermarchaeota phylum and highlight the anoxic, hot, deep marine crustal biosphere as an important habitat for understanding the evolution of early life.

Microbiology Resource Announcements
Draft Genome Sequences of Penicillium spp. from Deeply Buried Oligotrophic Marine Sediments – NEW!
Morgan S. Sobol, Tatsuhiko Hoshino, Taiki Futagami, Fumio Inagaki, Brandi Kiel Reese*
*C-DEBI Contribution 458

Here, we report genome sequences of two Penicillium isolates from below the seafloor of the oligotrophic South Pacific Gyre. These genomes are the first reported for fungi from deeply buried marine sediment. Both genomes will provide valuable information regarding the role of fungi and carbon cycling in the energy-limited subsurface biosphere.

Geobiology
The kinetics of siderophore-mediated olivine dissolution – NEW!
Mark A. Torres*, Sijia Dong, Kenneth H. Nealson, A. Joshua West
*C-DEBI Contribution 460

Silicate minerals represent an important reservoir of nutrients at Earth's surface and a source of alkalinity that modulates long‐term geochemical cycles. Due to the slow kinetics of primary silicate mineral dissolution and the potential for nutrient immobilization by secondary mineral precipitation, the bioavailability of many silicate‐bound nutrients may be limited by the ability of micro‐organisms to actively scavenge these nutrients via redox alteration and/or organic ligand production. In this study, we use targeted laboratory experiments with olivine and the siderophore deferoxamine B to explore how microbial ligands affect nutrient (Fe) release and the overall rate of mineral dissolution. Our results show that olivine dissolution rates are accelerated in the presence of micromolar concentrations of deferoxamine B. Based on the non‐linear decrease in rates with time and formation of a Fe³⁺‐ligand complex, we attribute this acceleration in dissolution rates to the removal of an oxidized surface coating that forms during the dissolution of olivine at circum‐neutral pH in the presence of O₂ and the absence of organic ligands. While increases in dissolution rates are observed with micromolar concentrations of siderophores, it remains unclear whether such conditions could be realized in natural environments due to the strong physiological control on microbial siderophore production. So, to contextualize our experimental results, we also developed a feedback model, which considers how microbial physiology and ligand‐promoted mineral dissolution kinetics interact to control the extent of biotic enhancement of dissolution rates expected for different environments. The model predicts that physiological feedbacks severely limit the extent to which dissolution rates may be enhanced by microbial activity, though the rate of physical transport modulates this limitation.
 

Scientific American's "The Artful Amoeba" Blog: Inside Earth, Microbes Approach Immortality – NEW!
Earth’s crust appears to be simply lousy with idling, ancient bacteria parked in power-save mode, ready at nearly a moment’s notice to throw the gearshift into drive. But what a life! Eons spent entombed in a dark, airless, silent matrix, barely eating, barely breathing, barely moving, barely living. But not dead. Not dead. Featuring the modeling study from C-DEBI Contribution 438 (Bradley et al., 2018 in Geobiology).

Proposal Calls

Frontier Research in Earth Sciences (FRES)
Full proposal deadline date: February 21, 2019 .

IODP-USSSP: Apply to Sail on Expedition 387: Amazon Margin
The deadline to apply is March 1, 2019.

AGU: Submit a nomination for the Taira Prize
Deadline to nominate: March 15, 2019.

IODP-USSSP: Apply to Sail on Expedition 388: Equatorial Atlantic Gateway
The deadline to apply is April 1, 2019.

NSF: Opportunities for Promoting Understanding through Synthesis (OPUS)
Full proposal deadline: August 5, 2019.

NSF: Biological Oceanography
Full proposal deadline date: August 15, 2019.

NSF: Chemical Oceanography
Full proposal deadline date: August 15, 2019.

NSF: Physical Oceanography
Full proposal deadline date: August 15, 2019.

NSF: Accelerating Research through International Network-to-Network Collaborations (AccelNet) – NEW!
This solicitation invites proposals for the creation of international networks of networks in research areas aligned either with one of the NSF Big Ideas or a community-identified scientific challenge with international dimensions. AccelNet awards are meant to support the connections among research networks, rather than supporting fundamental research as the primary activity.  Each network of networks is expected to engage in innovative collaborative activities that promote synergy of efforts across the networks and provide professional development for students, postdoctoral scholars, and early-career researchers. There are two proposal categories covered by this solicitation: Catalytic and Full-Scale Implementation. Letter of intent due date: October 30, 2019.

NSF: Research Traineeship (NRT) Program
Next letter of intent window: November 25, 2019 – December 6, 2019.

Rolling Calls:

• C-DEBI: Rolling call for Research Exchange proposals
• DCO: Deep Life Cultivation Internship Program
• IODP-USSSP: Proposals for Pre-Drilling Activities
• NSF: Arctic Sciences Program Solicitation
• NSF: Division of Environmental Biology (core programs) (DEB)
• NSF: Infrastructure Innovation for Biological Research (IIBR)
• NSF: Instrument Capacity for Biological Research (ICBR)
• NSF: Non-Academic Research Internships for Graduate Students (INTERN) Supplemental Funding Opportunity
• NSF: Research Assistantships for High School Students (RAHSS): Funding to Broaden Participation in the Biological Sciences
• NSF: Research Experience for Teachers (RET): Funding Opportunity in the Biological Sciences
• NSF: Tribal Colleges and Universities Program (TCUP)

Employment

MBL: Faculty Position in Evolutionary Genomics and Molecular Evolution
For full consideration applications should be submitted by March 1, 2019.

MSU: Assistant/Associate Professor of Environmental Microbiology

Princeton University: Assistant Professor

U Toronto: Postdoctoral Positions in Fluid-Rock Interactions and Deep Subsurface Life

TAMU: Instructional Assistant Professor