Kent j. voorhees

 

PROFESSOR

BS - Utah State University
MS - Utah State University
PhD - Utah State University
Postdoctoral Study - Michigan State University

RESEARCH DESCRIPTION

Dr. Voorhees’ research focuses in two major areas: 1) rapid bacterial identification and 2) biofuels characterization.
Bacteriophages are viruses that infect bacteria; for example, MS2 coliphage infects Enterobacteria including Escherichia coli. When the bacteriophage attacks the bacterial cell, the virus takes over the cell biochemistry for the purpose of viral replication. In the case of MS2, estimates for the number of progeny per infected cell range from 10,000 to 20,000. Each of these progeny is composed of many proteins that are unique to the virus. For example, MS2 coliphage contains 180 copies of a single protein that forms a capsid shell around the nucleic acids. Theoretically, there could be almost two million capsid proteins in a single infected bacterial cell (one bacterial cell x the number of proteins in capsid x burst size). Fifteen minutes after infection, Matrix Assisted Laser Desorption Ionization (MALDI-MS) can be used to detect these proteins and hence the presence of the bacteria.
Phage amplification combined with MALDI-MS or lateral flow immunochromatography (LFI) makes it possible to detect bacteria at very low concentrations. For example, detection limits for E. coli at 103-104 cells/mL have been demonstrated, an improvement over the stand-alone analytical detector by a factor of more than 103. The phage research is funded by DTRA to develop detectors for Francisella tularensis, B. anthracis, Y. pestis, Burkholderia mallei, and Burkholderia pseudomallei.
The biofuels project is a collaborative effort with Professor Matt Posewitz funded by Conoco-Phillips), and the National Renewable Energy Laboratory (NREL). The NREL portion centers on identifying highly toxic combustion products (nitropolycyclic aromatic hydrocarbons) from engines fueled with diesel and/or biodiesel, and characterization of biodiesel precipitates. Dr. Posewitz studies biofuels production from algae. We provide GC/MS support for characterizing of the fatty acid content in the algae as well as analysis of liquid products.
Students working with Dr. Voorhees develop strong analytical and bio backgrounds. Because of the interdisciplinary nature of the research, past Ph.D. students have accepted jobs at instrument manufacturers, biotech firms, Center for Disease Control, postdoctoral appointments, and University faculty positions.

SELECTED PUBLICATIONS

Ratcliff M.A., Dane A.J., Williams A., Ireland J., Luecke J., McCormick R.L., Voorhees K.J. Diesel Particle Filter and Fuel Effects on Heavy-Duty Diesel Engine Emissions Environmental Science & Technology 2011, 44, 8343 - 8349.
 
McAlpin C.R., Cox C.R., Matyai S.A., Voorhees K.J.  Enhanced matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analysis of bacteriophage major capsid proteins with beta-mercaptoethanol pretreatment Rapid Communications in Mass Spectrometry 2010, 24, 11 - 14.

Harvey C.D., Dane A.J., Abbas-Hawks C., Voorhees K.J. Detection of nitro-polycyclic aromatic hydrocarbons in mainstream and sidestream tobacco smoke using electron monochromator-mass spectrometry Environmental Chemistry Letters 2009, 7, 331 - 336.
 
Reiman R.W., Atchley D.H., Voorhees K.J. Indirect detection of Bacillus anthracis using real-time PCR to detect amplified gamma phage DNA Journal of Microbiological Methods 2007, 68, 651 - 653.

Harvey C.D., McCormick R.L., Hayes R.R., Dane A.J., Voorhees K.J. Analysis of nitro-polycyclic aromatic hydrocarbons in conventional diesel and Fischer-Tropsch diesel fuel emissions using electron monochromator-mass spectrometry Anal. Chem. 2006, 78, 4894 - 4900.