Tonya Peeples
Associate Professor (2002)
Assistant Professor (1995)
B.S. 1988, North Carolina State
Ph.D. 1995, The Johns Hopkins University
319/335-2251; fax: 319/335-1415
tonya-peeples@uiowa.edu
Research Interests:
extremophile
biotechnology
Organisms that thrive in extreme environments are of interest in the production of highly stable enzymes and in the development of innovative bioprocesses. One area of focus in my laboratory is development and realization of the biocatalytic potential of extremophilic microbes. Most of these extremophiles belong to a recently defined domain of microbes known as the Archaea.
Individual organisms may live at temperatures near boiling or under high pressures, in the presence of high salt or in highly acidic environments.
We also are interested in developing environmentally relevant biotechnology based on mesophilic microorganisms' ability to degrade recalcitrant pollutants. Much of this work requires enrichment and characterization of single microbes and mixed cultures that can survive in high concentrations of pollutants. We also are considering genetically engineered systems that would allow incorporation of several enzyme steps in novel degradative pathways.
Design of Biocatalytic Systems
In our application of single species or mixed cultures of microbes, we evaluate microbial physiology in conjunction with industrially relevant biotransformations. These efforts, which involve the design and evaluation of new biocatalytic systems, provide great learning opportunities for graduate and undergraduate chemical engineers. We use knowledge of molecular biology, classical cellular physiology, and bioprocess design as tools of discovery.
Areas that may be quick to benefit from this work include applications involving enzymes or whole-cell processing. Extremophilic microbes may have potential impact in fields such as mining, waste treatment, and bioremediation. In particular, we are studying the use of thermoacidophilic archaea in metals leaching, of hyperthermophilic anaerobes in waste degradation, and of archaea and bacteria in the degradation of environmental pollutants.
The physiology and energetic manipulation of metal leaching organisms are significant but not exclusive to gold, copper, and uranium leaching and recovery of metals such as arsenic, silver, and mercury. Hyperthermophilic anaerobes encompass a wide metabolic variety useful for the design of high-temperature anaerobic digestors that convert waste to higher value products. Finally, an understanding of microbial stability under extremes may allow the identification and molecular engineering of enzymes and pathways that break down organic pollutants.
-------------------------------------------------------------------------------Selected Publications
Li, M., Terc, H.A., Kim, J-W and Peeples, T. L. (2003) "Energy-cost Reduction in Starch Processing Using Aqueous Two Phase Reactor Systems" Separation Science and Technology 38(12 & 13), 2709-2724Peeples, T. L. (2003) “Biochemical Engineering”, in Science Careers: Advice From Experts, Flowers, L. O, ed. Scarecrow Press, Lanham MD
Peeples, T L. (2003). “Introduction to Biochemical Engineering: Synthesis, Resourcefulness, and Effective Communication in Group Learning“ Chemical Engineering Education” 37(3) 174-179Olivo, H., T. L. Peeples, M. Y. Rios, F. Valazques, J.-W. Kim, and S. Narang. (2003).”Microbial C-hydroxylation and -4-O-methylglucosidation of methyl-benzamide ethers” J. Mol. Biocatal. B, 21, 97–105
Hanford, M.J. and Peeples, T.L. (2002) "Commerical Applications of Extremophilic Tetraether Lipids," Applied Biochemistry and Biotechnology 97: 45-62.
Li, M., Kim, J.W., and Peeples, T.L. (2002) "Amylase Partitioning and Extractive Bioconversion of Starch using Thermoseparating Aqueous Two-phase Systems," Journal of Biotechnology, 93(1):15-26.
Li, M., Kim, J-W., and Peeples, T.L. (2002) "Kinetic Enhancement of Starch Bioconversion in Thermoseparating Aqueous Two-phase Reactor Systems," Biochemical Engineering Journal, 3582:1-8.
Kim, J-W., Flowers, L, Terc, H., Whiteley, M., and Peeples, T.L. (2001) "Novel, Thermostable Family-13 Glycoside Hydrolase from Methanococcus jannaschii," Folia Microbiologica, 46(6): 475-481.
Kim, J-W., Flowers, L., Whiteley, M., and Peeples, T.L. (2001) "Biochemical Confirmation of the Family 57-like alpha-amylase of Methanococcus jannaschii," Folia Microbiologica, 46(6):467-473.
Brown, R.C., Rometto, A., Peeples, T.L., Khiyami, M., Voss, B., Kim, J-W., and Fisher,S. (2000) "Strategies for Pyrolytic Conversion of Herbaceous Biomass to Fermentation Products," In Proceedings of the 9th Biennial Bioenergy Conference.
Stoylar, S., Costello, A.M., Peeples, T.L., and Lidstrom, M.E. (1999) "Physiological Basis for Three Genetic Copies of Particulate Methane Monooxygenase: Cloning and Mutant Analysis," Microbiology, 145(Part 5): 1235-1244.
Peeples, T.L. and Kelly, R.M., (1995) "Bioenergetic Response of the Extreme Thermoacidophile Metallosphaera sedula to Thermal and Nutritional Stress," Applied and Environmental Microbiology, Vol. 61, No. 6, pp. 2314-2318.
Kelly, R.M., Peeples, T.L. and Halio, S.B. (1994) "Metabolic Strategies and Biotechnological Potential for Heterotrophic and Mixotrophic Extremely Thermophilic Microorganisms," Annuals-New York Academy of Sciences, Vol.745, pp. 409-413.
Schicho, R.N., Brown, S.H., Blumentals, I.I., Peeples, T.L., Duffaud, G.D., and Kelly, R.M. (1994) "Continuous Culture Techniques for Extremely Thermophilic and Hyperthermophilic Microorganisms," In, Archaea: A Laboratory Manual, F.T. Robb, Ed., Cold Spring Harbor Press.
Peeples, T.L. and Kelly, R.M. (1994) "Bioenergetics of the Metal/Sulfur Oxidizing Extreme Thermophile, Metallosphaera sedula," Fuel, Vol 72, No. 12, pp. 1619-1624.
Peeples, T.L., Hirosue, S., Olson, G.J., and Kelly, R.M. (1991) "Coal Sulfur Transformations Monitored by Hyperthermophilic Archaebacteria, "Fuel, Vol. 70, pp. 599-604.