search
NABIR Home Page Help NABIR Site Organization/Index Contacts NABIR PI Calendar Conferences Calls for Proposals
   

  • 8-31-2005. AGU Outstanding Student Paper Award. Kenneth Hurst Williams of LBNL/UC Berkeley received an outstanding student paper award for presentation of his investigations using geophysical techniques to interrogate stimulated subsurface microbial processes at this year’s Spring AGU Joint Assembly meeting this past May in New Orleans. LA. Awardees names and presentation titles have been published in AGU’s weekly journal EOS (Vol. 86, no. 34, pp. 312, August 23, 2005). Ken is exploring the use of self potential (SP) measurements as a means to monitor and track redox changes induced in the subsurface upon the stimulation of metal and sulfate-reducing conditions. In situ bioremediation processes under investigation within the NABIR program stimulate the activity of naturally-occurring bacteria found in the subsurface to immobilize metal and radionuclide contaminants thereby preventing further transport of these contaminants in groundwater. Ken’s NABIR-supported work is of significance because it demonstrates a potential technique for monitoring the progression of subsurface bioremediation processes using surface deployed techniques instead of expensive drilling operations. This research was recently featured in an Online News article on the website for the journal Environmental Science & Technology (http://pubs.acs.org/subscribe/journals/esthag-w/2005/aug/tech/rp_microbes.html) and has been accepted for publication in ES&T and is posted on ES&T’s Research ASAP website (http://pubs3.acs.org/acs/journals/toc.page?incoden=esthag&indecade=&involume=0&inissue=0).

  • 6/23/2005 An Electrifying Discovery: NABIR-supported researcher Dr. Derek R. Lovley of the University of Massachusetts, Amherst has made a remarkable discovery that has been published in the journal Nature. Dr. Lovley’s group has found that the metal-reducing microorganism Geobacter produces nanotube projections called pili on the outer cell surface that appear to function as electron conducting nanowires. The data indicates these conductive pili are conduits by which Geobacter transfers electrons onto iron oxides during the process of dissimilatory iron reduction.  This is of importance because Geobacter species are detected as a dominant species in the subsurface during stimulated uranium bioremediation, where iron oxide reduction is a dominant process. Discovery of this fundamental mechanism of microbial metal reduction could lead to better models for subsurface bioremediation processes but may also have implications for the electronics field because the conducting pili can be mass produced and pili composition can be altered via genetic manipulation.
    Nature 435, 1098-1101 (23 June 2005)

  • 9/27/2004  The Metallic Secret of Deinococcus radiodurans’ Success: Researchers at the Uniformed Services University of the Health Sciences (USUHS) in Bethesda, MD USA report a chemical basis for radiation resistance in the bacterium Deinococcus radiodurans, famous for its extreme resistance to X-rays and gamma rays, and the subject of research for 50 years. Cellular accumulation of high levels of manganese (Mn) in combination with low levels of  iron (Fe) appears to be key to recovering from radiation in Deinococcus and other resistant organisms. In contrast, Fe-rich, Mn-poor organisms are very sensitive to radiation. Intracellular Mn acts as a scavenger of free oxygen-radicals (antioxidant), whereas Fe does the reverse. The article presents a different view of how radiation kills cells. Previously, DNA damage caused during the course of irradiation was considered to be the overriding cause of cell death. Instead, the paper points to potential therapeutic applications that should be further investigated. For example, it is possible that by restricting the intake of antioxidants in patients undergoing radiation therapy (eg. Mn(II), vitamin E), cancer cells might be rendered more sensitive; and the reverse to facilitate recovery of normal cells after radiation therapy. Development of treatments to protect from radiation injury are also important to manned space flight, workers at nuclear power plants, or in planning responses to a terrorist’s dirty bomb. The USUHS team, led by Dr. Michael Daly, is also dedicated to engineering Deinococcus for cleanup of Cold War radioactive wastes stored at the Hanford Site, Richland, WA, USA and other US Department of Energy waste storage facilities.Originally published in Science Express on 30 September 2004
    Science, Vol 306, Issue 5698, 1025-1028, 5 November 2004
  • Elemental and Redox Analysis of Single Bacterial Cells by X-ray Microbeam Analysis: NABIR program researcher, Dr. Kenneth M. Kemner of Argonne National Laboratory (ANL), Dr. Kenneth H. Nealson of the University of Southern California and colleagues appear in the Oct 22, 2004 issue of Science. Dr. Kemner’s expertise is in application of highly focused synchrotron-based x-rays to probe biogeochemical processes occurring at the microbe-mineral interface. The analytical technique developed by Kemner at the Advanced Photon Source (APS) is noninvasive and allows the researchers to interrogate living, hydrated biological samples at the nanometer scale (150nm). Using this microprobe technology, Dr. Kemner and colleagues document changes in morphology and elemental composition of both planktonic (i.e. free-swimming) and surface adhered, single bacteria before and after exposure to high concentrations of toxic Cr(VI). The results show that surface adhered bacteria tolerate chromium better than planktonic cells and accumulate elements such as calcium and phosphorus associated with the production of extracellular polysaccharide (EPS). X-ray absorption near-edge spectroscopy (XANES) analyses of surface adhered bacteria implied that Cr(VI) was reduced to Cr(III) within the EPS layer. Several differences also were observed in the distribution of transition metal abundance within surface adhered cells relative to planktonic cells. These results demonstrate that it is now possible to monitor nanoscale changes in elemental composition and redox chemistry within and around a single bacterial cell, an ability that could prove invaluable during investigations of biogeochemical processes in the environment. Science, Vol 306, Issue 5696, 686-687 , 22 October 2004
  • The Planet Protectors: Time magazine article with Derek Lovley

  • Mining Bacteria's Appetite for Toxic Waste Researchers Try to Clean Nuclear Sites with Microbes

  • Energy Department-funded Scientists Decode DNA of Bacterium that Cleans Up Uranium Contamination and Generates Electricity

  • Scott Fendorf Wins Soil Science Award
    Dr. Scott Fendorf, Professor of Soil and Environmental Chemistry at Stanford University and long-time NABIR investigator, has received this years Marion L. and Chrystie M. Jackson Soil Science Award. This award is designed to recognize midcareer soil scientists who have made outstanding contributions to the areas of soil chemistry and mineralogy. The award is the Soil Science Society of America premiere midcareer research award for which competition is intense. The principal criteria for the award are: (1)significance and originality of basic and/or applied research in soil chemistry/mineralogy; (2) excellence in creative reasoning and skill in obtaining pertinent data; (3) quality of teaching soil chemistry/mineralogy at undergraduate and/or graduate levels; and (4) total impact of contributions on soil science and other fields, nationally or internationally, as well as on society at large.

  • BIOREMEDIATION: Anaerobes to the Rescue Derek R. Lovley in SCIENCE Magazine