Table of Contents

• Coverage
• Dataset Description
  • Data Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Project Information
• Program Information
• Funding

Processing Notes from Researcher:

Sequence data were processed according to Wetmore et al (2015). Following quality control, an average of 35,090 unique barcodes mapped to insertions that fell within the interior 10 to 90% of R. pomeroyi coding sequences. In total, 55 million reads were mapped to insertions in 3,570 genes (out of 4,469 protein-encoding genes in the R. pomeroyi genome) with a median of 404,513 mapped reads per sample. Reads mapping to different insertion sites within the same coding sequence were pooled.

BCO-DMO Processing Notes:

• Removed spaces and special characters from column header names (replaced with underscores "_")

Project:

Observing expression of marine bacterial transporter systems with transcriptomic or proteomic tools can provide valuable information about the metabolomic environment. However, these ‘omics approaches are limited by the low rate of transporter gene annotation. Here, a barcoded, arrayed, mutant library of the marine bacterium Ruegeria pomeroyi DSS-3 is employed in high throughput screens to identify the target substrates of 13 transporter systems. A set of 156 isolated putative transporter mutants were screened for growth on minimal medium with 63 substrates, each as a sole carbon source. Mutants that demonstrated a growth defect on a specific substrate were selected for secondary, higher resolution, growth screening. Mutants that continued to demonstrate growth defect relative to the pooled-mutant library (pooled-BarSeq, used as an analog for wildtype) were screened for their ability to drawdown the target substate. Gene annotations were made when mutants of the given transporter demonstrated both growth and drawdown defects on the target substrate.

In addition to the isolated mutant screens, the pooled barcoded transposon mutant library (pooled-BarSeq) was grown on minimal medium with selected substrates, each as sole carbon source, such that the relative enrichment or depletion of each mutant could demonstrate its fitness cost associated with the loss of each disrupted gene when grown on each substrate. The results of pooled-BarSeq screens had mixed consistency with the isolated mutant screens, demonstrating the value of isolated mutants for transporter annotation.

Program:

The Center for Chemical Currencies of a Microbial Planet (C-CoMP) integrates research, education and knowledge transfer activities to develop a mechanistic understanding of surface ocean carbon flux within the context of a changing ocean and through increased participation in ocean sciences. C-CoMP supports science teams that merge biology, chemistry, modeling, and informatics to close long-standing knowledge gaps in the identities and dynamics of organic molecules that serve as the currencies of elemental transfer between the ocean and atmosphere.

Functions carried out by microscopic inhabitants of the surface ocean affect every aspect of life on our planet, regardless of distance from the coast. Ocean phytoplankton are responsible for half of the photosynthesis on Earth, the first step in a complex system that annually withdraws 50 billion metric tons of carbon from the atmosphere to sustain their growth. Of this, 25 billion metric tons participate in a rapid cycle in which biologically reactive material is released into seawater and converted back into carbon dioxide by marine bacteria within hours to days. The chemical-microbe network at the heart of this fast cycle remains poorly constrained; consequently, its primary currencies and controls remain elusive; its sensitivities to changing ocean conditions are unknown; and its responses to future climate scenarios are not predictable. The Center for Chemical Currencies of a Microbial Planet (C-CoMP) integrates research, education and knowledge transfer activities to develop a mechanistic understanding of surface ocean carbon flux within the context of a changing ocean and through increased participation in ocean sciences. C-CoMP supports science teams that merge biology, chemistry, modeling, and informatics to close long-standing knowledge gaps in the identities and dynamics of organic molecules that serve as the currencies of elemental transfer between the ocean and atmosphere. C-CoMP fosters education, outreach, and knowledge transfer activities that engage students of all ages, broaden participation in the next generation of ocean scientists, and extend novel open-science approaches into complementary academic and industrial communities. The Center framework is critical to this mission, uniquely facilitating an open exchange of experimental and computational science, methodological and conceptual challenges, and collaborations that establish integrated science and education partnerships. With expanded participation in ocean science research and ocean literacy across the US society, the next generation of ocean scientists will better reflect the diverse US population.

Climate-carbon feedbacks on the marine carbon reservoir are major uncertainties for future climate projections, and the trajectory and rate of ocean changes depend directly on microbial responses to temperature increases, ocean acidification, and other perturbations driven by climate change. C-CoMP research closes an urgent knowledge gap in the mechanisms driving carbon flow between ocean and atmosphere, with global implications for predictive climate models. The Center supports interdisciplinary science teams following open and reproducible science practices to address: (1) the chemical currencies of surface ocean carbon flux; (2) the structure and regulation of the chemical-microbe network that mediates this flux; and (3) sensitivity of the network and its feedbacks on climate. C-CoMP leverages emerging tools and technologies to tackle critical challenges in these themes, in synergy with existing ocean programs and consistent with NSF’s Big Ideas. C-CoMP education and outreach activities seek to overcome barriers to ocean literacy and diversify participation in ocean research. The Center is developing (1) initiatives to expand ocean literacy in K-12 and the broader public, (2) ocean sciences undergraduate curricula and research opportunities that provide multiple entry points into research experiences, (3) post-baccalaureate programs to transition undergraduates into graduate education and careers in ocean science, and (4) interdisciplinary graduate student and postdoctoral programs that prepare the next generation of ocean scientists. The C-CoMP team includes education faculty who evaluate the impacts of education and outreach activities and export successful STEM initiatives to the education community. C-CoMP is revolutionizing the technologies for studying chemical transformations in microbial systems to build understanding of the outsized impact of microbes on elemental cycles. Open science, cross-disciplinary collaborations, community engagement, and inclusive practices foster strategic advances in critical science problems and STEM initiatives. C-CoMP science, education, and knowledge-transfer themes are efficiently addressed through a sustained network of scientists addressing critical research challenges while broadening the workforce that will tackle multi-disciplinary problems with academic, industrial and policy partners.

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.

The Program's Data Management Plan (DMP) is available as a PDF document.