News from Department of Energy, Office of Science

Yongqin Jiao: Then and Now / 2011 Early Career Award Winner

I won the Early Career Research Program Award shortly after I transitioned from postdoc to staff scientist at Lawrence Livermore National Laboratory (LLNL). The award accelerated my growth towards scientific independence by providing five years of stable funding. It also gave me the confidence that I could achieve my goals.

The goal of my grant was to understand how a common freshwater bacterium often used in laboratory studies as a model organism, Caulobacter crescentus, survives under high levels of uranium. What was its potential use for bioremediation, to clean up soil and groundwater contaminated with uranium?

I wanted to build a systems-level understanding of Caulobacter physiology that focused on its ability to utilize the formation of uranium phosphate minerals. 

The project was highly interdisciplinary. I worked with a team of microbiologists, systems biologists, cell biologists, and geochemists. This early exposure to interdisciplinary research had a profound impact on my ability to incorporate diverse expertise into my approach to solving complex problems. I rely heavily on that ability today. 

The idea for my Early Career grant came from a comment made by Prof. Lucy Shapiro at Stanford University. She noted that there were limitations to working with uranium on the Stanford campus. This was the kind of mission-relevant research that was more suited to a national lab setting. This project helped me identify a career niche that aligns my research interest with LLNL’s capabilities and strengths. 

In addition, the elegant and fascinating Caulobacter cell cycle captivated my curiosity and passion; it highlighted the utility of systems biology research. 

Building on our deep understanding of Caulobacter physiology, my team was able to apply and develop two innovative Caulobacter-based biotechnologies. One was a uranium biosensor that can detect the presence of uranium from contaminated groundwater. The other was biosorption technology for rare earth recovery through ligand display on Caulobacter’s surface layer.

The systems biology expertise that I gained from this project established a strong science foundation for my career growth. 

Yongqin Jiao is a scientist and Group Leader in the Biosciences and Biotechnology Division at Lawrence Livermore National Laboratory.

The Early Career Research Program provides financial support that is foundational to early career investigators, enabling them to define and direct independent research in areas important to DOE missions. The development of outstanding scientists and research leaders is of paramount importance to the Department of Energy Office of Science. By investing in the next generation of researchers, the Office of Science champions lifelong careers in discovery science.

For more information, please go to the Early Career Research Program.

Systems Level Investigation of Uranium Resistance and Regulation by Caulobacter Crescentus

Microbes are known to play a major role in influencing the movement of uranium and other environmental contaminants. In addition to simply surviving exposure to radionuclides, some microbes can use these compounds to promote their growth, altering their chemical state to restrict their movement in the environment. However, understanding of the basic mechanisms that microbes use to perform these metabolic reactions is limited, especially in environments exposed to oxygen. In this research project, the biological systems of the bacterium Caulobacter crescentus that allow it to detect uranium in the environment, accumulate the metal at the cell's surface, and use it to generate energy via respiratory metabolism (essentially "breathing" uranium) will be examined. The long term goal of the project is to develop a conceptual model of uranium cycling that could be used to understand processes occurring at contaminated sites and inform potential bioremediation strategies.

D.M. Park, K.W. Overton, M. Liou, and Y. Jiao, “Identification of a U/Zn/Cu responsive global regulatory two-component system in Caulobacter crescentus.”  Molecular Microbiology 104, 46 (2017). [DOI:10.1111/mmi.13615]

K.W. Overton, D.M. Park, M.C. Yung, J. Smit, and Y. Jiao, “Two outer membrane proteins contribute to cellular fitness in Caulobacter crescentus by preventing intracellular S-layer protein accumulation.”  Appl Environ Microbiol 82, 6961 (2016). [DOI: 10.1128/AEM.02479-16]

M.C. Yung, D.M. Park, K.W. Overton, M.J. Blow, C.A. Hoover, J. Smit, S.R. Murray, D.P. Ricci, B. Christen, G.R. Bowman, and Y. Jiao, “Transposon mutagenesis paired with deep sequencing of Caulobacter crescentus under uranium stress reveals genes essential for detoxification and stress tolerance.” J. Bacteriol. 197, 3160 (2015). [DOI: 10.1128/JB.00382-15]

 

DOE Explains… offers straightforward explanations of key words and concepts in fundamental science. It also describes how these concepts apply to the work that the Department of Energy’s Office of Science conducts as it helps the United States excel in research across the scientific spectrum. For more information on microorganisms and DOE’s research in this area, please go to DOE Explains…Microbiology.” For more information on systems biology, please go to “DOE Explains…System Biology

 

Additional profiles of the Early Career Research Program award recipients can be found on the Early Career Program Page.

The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit www.energy.gov/science.