Office of Biological and Environmental Research Weekly Report

May 26, 2008

Study of Aerosol Indirect Effects in China Begins: Beginning May 19, 2008, the Office of Science’s Atmospheric Radiation Measurement (ARM) Climate Research Facility is deploying its portable atmospheric laboratory in southeastern China, a dominant economic and industrial zone in East Asia. In order to examine the link between aerosols and clouds and their affect on the Earth’s atmosphere, the ARM Mobile Facility is located in Shouxian, about 500 km west of Shanghai. In addition, a supplemental facility with fewer but similar instruments is obtaining measurements at an observatory on the shores of Lake Taihu, just 96 km west of Shanghai. Both of these facilities will operate through December 2008. To measure regional differences in atmospheric properties, an ancillary facility with a subset of the ARM Mobile Facility instruments is operating at a location in the semi-desert conditions of Zhangye, in north-central China, from April through June. The ancillary facility then moves to Xianghe, on the northeast coast downstream of Beijing. It will operate in this primarily agricultural environment from July through the end of the ARM Mobile Facility deployment in December. In partnership with the Institute of Atmospheric Physics, Chinese Academy of Science, the study is being conducted under the “Climate Science” agreement established in 1987 between the DOE and China Ministry of Science and Technology.

Media Interest: Yes. Jin Qiu, Nature magazine UK affiliate, interviewed participants at the opening ceremony at Shouxian on May16. Her intent is to write an in-depth feature article.

Contact: Wanda Ferrell, SC-23.3, (301) 903- 0043

Office of Science Research Yields Understanding of Key Function of Uranium-Reducing Microbe. Biophysical research has provided an important clue about how bacteria move within radionuclide-contaminated sites, where they can reduce and immobilize these contaminants. Scientists at Argonne National Laboratory determined the three-dimensional structure of sensory domains of two proteins involved in movement of the bacterium Geobacter sulfurreducens. These domains are involved in chemotaxis, the means by which bacteria sense where to move to find nutrients or to avoid harmful chemicals. Binding of a stimulant molecule to a sensory domain on the outside of the cell transmits a signal to the interior of the cell, initiating the expression of proteins that enable the cell to move in response to the external stimulation. The Geobacter family is of particular interest because it is a major component of the microbial community in many subsurface environments contaminated by uranium. The Office of Science is supporting research into how Geobacter affects fate and transport of uranium in order to understand how this contamination could be remediated. The information obtained about the structure of the signaling domains will help to understand not only how microbes sense and move toward locations with higher uranium concentrations, but more generally respond to a variety of chemical changes in their environment. The Argonne research was led by Dr. Marianne Schiffer of the Biosciences Division and made use of the Structural Biology Center’s protein crystallography stations at the Advanced Photon Source. It was published in the April 11, 2008, issue of the Journal of Molecular Biology.

Media Interest: No

Contact: Roland F. Hirsch, SC-23.2, (301) 903-9009

Office of Science Researchers Write Editorial for Special Issue of Science on Microbial Ecology. James Tiedje and Timothy Donohue are authors of the editorial, “Microbes in the Energy Grid.” They point to the “incredible metabolic diversity of today’s microbial world” as a great resource for developing new routes to energy production from renewable sources and for mitigating climate change by increasing sequestration of carbon from the atmosphere. Microbes have already been identified that can carry out a wide range of chemical transformations that could be harnessed for meeting energy and climate challenges. Yet, as the authors emphasize, the vast majority of species of microbes on Earth are still unknown. Thus research in microbial ecology will undoubtedly identify many new capabilities that will help address societal needs in energy and the environment. They urge the scientific community to “inform the public and policy-makers about the research needed to bring the chemical and catalytic power of microbes to bear on meeting our ever-growing energy needs.” Jim Tiedje is professor of microbiology and crop and soil sciences and Director of the Center for Microbial Ecology at Michigan State University and Tim Donohue is professor of bacteriology at the University of Wisconsin, Madison, and Director of the Office of Science’s Great Lakes Bioenergy Research Center. The editorial appears in the May 23, 2008, issue of Science.

Media Interest: Yes

Contact: John Houghton, SC-23.2 (301) 903-8288