Dr. Joseph G. Leahy



Dr. Joseph G. Leahy

Associate Professor, Microbiology


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.

Visit the Leahy Lab page.

Curriculum Vitae


  • Ph.D., Microbiology, University of Maryland, 1993
  • M.S., Civil Engineering, The Ohio State University, 1985
  • B.S., Environmental Biology, The Ohio State University, 1982

Classes Taught


  • "Analysis of volatile and semivolatile hydrocarbons recovered from steam classified municipal solid waste." J. Environ. Qual. 33:1556-1561. Leahy, J.G., T.E. Carrington, and M.H. Eley (2004).
  • "Antimicrobial activity of Artemisia douglasiana leaf essential oil." Fitoterapia. 75:192-200. Setzer, W.N., B. Vogler, J.M. Schmidt, R. Rives, and J.G. Leahy.
  • "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., Z.M. Khalid, E.J. Quintero, J.M. Jones-Meehan, J.F. Heidelberg, P.J. Batchelor, and R.R. Colwell.
  • "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, M.C. Setzer, and W.N. Setzer (2003).
  • "Evolution of the soluble diiron monooxygenases." FEMS Microbiol. Rev. 27:449-479. Leahy, J.G., P.J. Batchelor, and S.M Morcomb (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., K.D. Tracy, and M.H. Eley (2003).
  • "The effect of organic carbon on the sequential reductive dehalogenation of tetrachloroethylene in landfill leachates." Water Research. 34:2390-2396. Leahy, J. G., and G.S. Shreve (2000).
  • "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. Sullivan, E.R., J.G. Leahy, and R.R. Colwell (1999).