FY2010 - Oak Ridge National Laboratory

Seed Money Fund—
Chemical Sciences Division
nonunique peptides in genome-related microbial species. Computational work was conducted to compare
the predicted vs. experimental “peptidome” to ascertain the level of uniqueness expected, and measured,
in these samples. We have extended this approach to evaluate a more complex 12-member microbial
consortia system from gnotobiotic mice cecal samples, in order to study how these microbial communities
impact, or respond to, diet-induced changes in the mouse. In particular, the microbiota from gnotobiotic
mice fed either high-fat or low-fat (chow) diets were examined in detail with this new experimental
approach. We were able to measure between 3,000 and 5,000 nonredundant proteins in each sample, and
found that the high-fat diet not only yielded more total microbial protein identifications but also revealed
a much higher level of metabolic activity in amino acid metabolism, carbohydrate metabolism, and
protein translation.
Information Shared
Mahowald, M.A., F. E. Rey, H. Seedorf, P. J. Turnbaugh, R. S. Fulton, A. Wollam, N. Shah, C. Y. Wang,
V. Magrini, R. K. Wilson, B. L. Cantarel, P. M. Coutinho, B. Henrissat, L. W. Crock, A. Russell,
N. C. Verberkmoes, R. L. Hettich, and J. I. Gordon. 2009. “Characterizing a model human gut
microbiota composed of members of its two dominant bacterial phyla.” Proc. Natl. Acad. Sci. 105,
5859–5864.
00514
An Ionic Liquids–Based Ion Detector
Peter T. A. Reilly
Project Description
Ionic liquids have been used to create an ion detector whose response is essentially independent of mass.
This ion detector comprises an electron multiplier integrated with an ionic liquid reservoir. Ions of any
size impact the surface of the ionic liquid in vacuum, whereupon ions from the liquid of the same net
charge and polarity are ejected. The interaction of particulate ions with ionic liquids is being explored as a
function of particle kinetic energy, mass and charge. The ability to detect ions without mass dependence
is the last major hurdle for the direct analysis of mass-specific species such as whole ribosomes, RNA,
DNA, or even viruses.
Mission Relevance
A DOE strategy within the arena of biological and environmental research, including genomic and related
biological sciences, is to create fundamentally new bioenergy sources and conversion processes. The
development of a mass-independent detector will permit the rapid analysis of high-molecular-weight
biological components that are relevant to our energy future. This improvement in analysis rate will
facilitate the discovery and evaluation of new energy source materials as well as efficient conversion
processes.
The mission of the National Institutes of Health will be greatly enhanced by the capabilities this detector
will provide. The high mass capability of the detector will enable the direct measurement,
characterization, and identification of complex mixtures of proteins, protein complexes, RNA, DNA, and
even viruses. The ability to analyze complex biological systems rapidly will accelerate advances in
proteomics. The Department of Homeland Security and the Department of Defense are greatly interested
in the rapid analysis of bacteria and viruses to analyze bioterrorist attack locations and battlefield settings.
This innovation enhances these analyses.
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