Video
Immobilizing Enzymes for Useful
Service 
Researchers
at DOE's Pacific Northwest National Laboratory have developed a technology
to immobilize high concentrations of active enzymes—harnessing twice
the activity than that of enzymes in free solution. Results of this research
are reported in the August 2002 Journal of the American Chemical Society.
(See Quicktime movie
(3572 KB). Courtesy of artist Mike Perkins and PNNL's Molecular Science
Computing Facility. Download
Quicktime 6.0)
3-D image of a Shewanella oneidensis
cell
Available as MPEG or Flash
This "movie" was created using 60 electron microscopy tomographic
images with the goal of constructing a 3-D representation of a Shewanella
oneidensis cell. This microbe has potential for use in waste cleanup
at DOE sites due to an ability to reduce and precipitate uranium, immobilizing
this contaminant and preventing its further movement in the soil. In the
movie, the uranium (precipitated in the presence of magnesium oxide) appears
as light "bumps" on the cell surface and near the inner surface
of the cell (periplasmic region) Also seen are cubes of reduced manganese
(rhodochrosite, a manganese carbonate) outside the cell. One goal of this
work is to use the tomography data to construct a physical model of S. oneidensis
upon which other cellular structures, proteins, and processes can be mapped
for a more complete understanding of the cells functions.
Credits: Alice Dohnalkova (PNNL, electron microscopy), Harold Trease (PNNL, modeling), Abel Lin (UCSD-NCMIR), Mason Mackey (USCD-NCMIR).
References:
- Fredrickson J. K., Zachara J. M., Kennedy D. W., Liu C., Duff M. C., Hunter D. B., and Dohnalkova A. (2002) Influence of Mn oxides on the reduction of Uranium(VI) by the metal-reducing bacterium Shewanella putrefaciens. Geochim. Cosmochim. Acta In press.
- Liu C., Zachara J. M., Fredrickson J. K., Kennedy D. W., and Dohnalkova A. (2002) Modeling the inhibition of the bacterial reduction of U(VI) by b-MnO2(s). Environ. Sci. Technol. 36, 1452-1459.
