Research area:

Environmental Microbiology and Biotechnology, Microbial Evolution

Research description:

My research interests center on the molecular genetic, physiological, ecological, and evolutionary aspects of hydrocarbon biodegradation in the environment.  The biodegradation of hydrocarbons by naturally-occurring bacteria and fungi and in soil and water is a global process which prevents the accumulation of these compounds, some of which are toxic and/or carcinogenic.  One important group of hydrocarbon contaminants is composed of the monoaromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene (BTEX), which are found in gasoline and other petroleum products.  I use molecular approaches to study the degradation of toluene by several well-characterized strains of toluene-oxidixing bacteria.  The purpose of my work is to gain a better understanding of the interrelationship between the genetic and physiological attributes of these bacteria and the effects of environmental conditions on their distribution, activity, and ability to degrade hydrocarbon contaminants.  I am also interested in phylogenetic (evolutionary) relationships among the enzymes which catalyze individual steps in the degradation of hydrocarbon substrates.

Publications (since 1999):

Leahy, J.G., T.E. Carrington, and M.H. Eley.  2004.  Analysis of volatile and semivolatile hydrocarbons recovered from steam classified municipal solid waste. J. Environ. Qual. 33:1556-1561.

Setzer, W.N., B. Vogler, J.M. Schmidt, R. Rives, and J.G. Leahy. Antimicrobial activity of Artemisia douglasiana leaf essential oil. Fitoterapia, 75:192-200,

Leahy, J.G., Z.M. Khalid, E.J. Quintero, J.M. Jones-Meehan, J.F. Heidelberg, P.J. Batchelor, and R.R. Colwell. Concentrations of hexadecane and inorganic nutrients modulate the production of extracellular membrane-bound vesicles, soluble protein, and bioemulsifier by Acinetobacter venetianus RAG-1 and Acinetobacter sp. strain HO1-N. Can. J. Microbiol., 49:569-575.

Leahy, J.G., P.J. Batchelor, M.C. Setzer, and W.N. Setzer. 2003. Isolation and characterization of a stilbene-degrading strain of Pseudomonas fluorescens, and production of antioxidant compounds by stilbene metabolism. Biosci., Biotechnol., and Biochem. 67: 2286-2287.

Leahy, J.G., P.J. Batchelor, and S.M Morcomb. 2003. Evolution of the soluble diiron monooxygenases. FEMS Microbiol. Rev. 27:449-479.

Leahy, J.G., K.D. Tracy, and M.H. Eley. 2003. Degradation of volatile hydrocarbons from steam-classified solid waste by a mixture of aromatic hydrocarbon-degrading bacteria. Biotechnol. Lett. 25:479-483.

Leahy, J.G., K.D. Tracy, and M.H. Eley. 2003. Degradation of mixtures of aromatic and chloroaliphatic hydrocarbons by aromatic hydrocarbon-degrading bacteria. FEMS Microbiol. Ecol. 43:271-276.

Leahy, J. G., and G.S. Shreve. 2000. The effect of organic carbon on the sequential reductive dehalogenation of tetrachloroethylene in landfill leachates. Water Research 34:2390-2396.

Sullivan, E.R., J.G. Leahy, and R.R. Colwell. 1999. Cloning and sequence analysis of the lipase and lipase chaperone-encoding genes from Acinetobacter calcoaceticus RAG-1, and redefinition of a Proteobacterial lipase family and an analogous chaperone family. Gene 230:277-285.