John Stolz

Director, Center for Environmental Research and Education; Professor, Environmental Microbiology
Bayer School of Natural and Environmental Sciences
Department of Biological Sciences; Center for Environmental Research and Education

215 Mellon Hall
Phone: 412.396.6333


NSF Postdoctoral Fellow, University of Massachusetts
NRC Research Associate, California Institute of Technology
Ph.D. Biology, Boston University, 1984
B.S. Biology, Fordham University, 1977

I am interested in both fundamental questions in microbial ecology as well as the application of unique microbial species for bioremediation. There are three major areas of interest in my lab:1) the ecophysiology, biochemistry, and molecular biology of dissimilatory metal reducing bacteria, 2) the ecophysiology of phototrophic prokaryotes and 3) the environmental impacts and microbiology of unconventional shale gas extraction. In the first area, I am investigating the reductases and electron transport system of several dissimilatory metalloid reducing bacteria. Respiration using alternative terminal electron acceptors such as arsenic and selenium oxyanions is a relatively new discovery. Ongoing studies include the characterization of the arsenic metabolism in the chemolithoautotroph Alkalilimnicol ehrlichii, selenium oxyanion reduction by Bacillus selenitireducens and Sulfurospirillum barnesii, and the biotransformation of inorganic arsenic and organoarsenicals. The second area involves research on community structure and biogenesis of modern marine stromatolites in the Bahamas and Shark Bay, Australia. The third area involves well water quality testing, GIS base mapping, and microbiological testing of fluids associated with Marcellus shale. The lab is currently funded by grants from the Heinz Endowments and Colcom Foundation.

Microbial metabolism of metals and metalloids

Arsenate eating bacteria can mobilize arsenic from rocks and sediments, transforming it into their more toxic forms (i.e. AsIII). Arsenic can also be important factor in the microbial ecology of lakes and subsurface waters. In Mono Lake and Searles Lake, in California, a robust arsenic cycle drives the microbial ecology. Our most recent discovery is that As(III) can serve as the electron donor in anoxygenic photosynthesis. Through the courtesy of the DOE Joint Genome Institute, five of our arsenic metabolizing organisms (Alkalilimnicola ehrlichii, Alkaliphilus oremlandii strain OhILAs, Bacillus selenitireducens, Deltaproteobacterium MLMS-1, Sulfurospirillum barnesii) have had their genomes sequenced and we are completing their annotation. The genome data has allowed us to use a proteomics approach for elucidating the pathways of inorganic and organic arsenic transformation. We also continue isolating and characterizing new species of bacteria, purifying and characterizing the terminal reductases and cytochromes involved in the reductive pathway, cloning and sequencing the genes encoding them, and developing biochemical and molecular probes for their detection in the environment. This work involves bacterial physiology, molecular biology, protein biochemistry, and field work.

Microbial community structure

Microbial mats and stromatolites are the oldest living ecosystems on the planet. These communities produce laminated structures (microbial mediated sedimentary structures, microbialites) and the fossil record indicates they dominated the Proterozoic world. Today they can be found in the warm waters of the Caribbean and Western Australia. We are studying the biogenesis of these structures, their lithification (cementing) and potential for preservation. Focusing on the stromatolites of the Bahamas and Shark Bay Australia, we use light, confocal, and electron microscopy to elucidate the microbe mineral interactions.

Well water quality in Southwestern Pennsylvania

Unconventional gas and oil development over the last fifteen years has transformed the region. In addition to the gas and oil wells, other infrastructure (compressor stations, processing plants, pipelines, injection wells) has been built and has posed a challenge to water quality. We have been monitoring surface and ground water quality in Southwestern Pennsylvania, with studies of Cross Creek County Park and Deer Lakes County Park as well as private water wells. The work involves sample collection and chemical analyses, GIS base mapping, and microbiological testing of fluids associated with Marcellus and Utica shales.

Dr. Stolz has published 92 peer reviewed articles, 38 book chapters, and two books.
  1. McDermott, T.R., Stolz, J.F., and Oremland, R.S. 2020. Arsenic and the gastrointestinal tract microbiome. Environmental Microbiology Reports. 12:136-159. doi: 10.1111/1758-2229.12814
  2. Cantlay,T., Eastham, J.L., Rutter, J., Bain, D.J., Dickson, B., Basu,P., and Stolz, J.F. 2020. Determining conventional and unconventional oil and gas well brines in natural samples: I Anion analysis with ion chromatography. Environmental Science and Health, Part A. 55:1-10, DOI: 10.1080/10934529.2019.1666560
  3. Cantlay,T., Bain, D.J., Curet, J., Jack, R.F., Dickson, B.C., Basu, P., and Stolz, J.F. 2020. Determining conventional and unconventional oil and gas well brines in natural samples: II Cation analysis with ICP-MS and ICP-OES. Environmental Science and Health, Part A. 55:11-23, DOI: 10.1080/10934529.2019.1666561
  4. Cantlay, T., Bain, D.J., and Stolz, J.F. 2020. Determining conventional and unconventional oil and gas well brines in natural samples: III Assessment of mass ratio analyses. Environmental Science and Health, Part A. 55:24-32, DOI: 10.1080/10934529.2019.1666562
  5. Mintmier, B., Nassif, S., Stolz, J.F., and Basu, P. 2020. Functional mononuclear molybdenum enzymes: challenges and triumphs in molecular cloning, expression, and isolation. J Biol Inorg Chem. doi: 10.1007/s00775-020-01787
  6. Stolz, J.F., and Basu, P. 2020. Arsenate respiratory reductase. Encyclopedia of Inorganic and Bioinorganic Chemistry. Wiley-Blackwell, eibc2744
  7. Wells, M., McGarry, J., Gaye, M.M., Basu,P., Oremland,R.S., and Stolz, J.F. The respiratory selenite reductase from Bacillus selenitireducens strain MLS10. 2019. J Bacteriol. 13;201(7). pii: e00614-18. doi: 10.1128/JB.00614-18
  8. Mason, D.M., Wang, Y., Bhatia, T.N., Miner, K.M., Trbojevic, S.A., Stolz, J.F., Luk, L.C., and Leak, R.K. 2019. The center of olfactory bulb-seeded a-synucleinopathy is the limbic system and the ensuing pathology is higher in male than in female mice. Brain Pathol. 2019. 29:741-770. doi: 10.1111/bpa.12718
  9. Stolz, J.F. and Basu, P. 2018 Unraveling the inner workings of respiratory arsenate reductase. Proc. Nat. Acad. Sci. 115:9051-9053.
  10. Suosaari, E.P., Awramik, S.M., Reid, R.P., Stolz, J.F., and Grey, K. 2018. Living dendrolitic microbial mats in Hamelin Pool, Shark Bay, Western Australia. Geosciences 8:212-228. doi:10.3390/geosciences8060212 (Journal Cover)
  11. Oremland, R.S., Saltikov, C., Stolz, J.F., and Hollibaugh, J.T. 2017. Autotrophic microbial aresenotrophy in arsenic-rich soda lakes. FEMS Microbiol. Ecol. 15:364-374. (Received Outstanding Review Recognition by FEMS)
  12. Hoeft McCann, S., Conrad, A., Hernandez-Maldonado, J., Stoneburner, B., Saltikov, C., Stolz, J.F., and Oremland, R.S., 2017. Arsenite as an electron donor for anoxygenic photosynthesis: Description of three strains of Ectothiorhodospira from Mono Lake, California and Big Soda Lake, Nevada. Life 7(1) 1/ doi 10.3390/life7010001
  13. Stolz, J.F. 2017. Gaia and her microbiome. FEMS Microbiol. Ecol. 10.1093/femsec/fiw247
  14. Switzer Blum, J., Hoeft McCann, S., Bennett, S., Miller, L.J., Stolz, J.F., Stoneburner, B., Saltikov, C. & Oremland R.S. 2016: A microbial arsenic cycle in sediments of an acidic mine impoundment: Herman Pit, Clear Lake, California., Geomicrobiology Journal, DOI:10.1080/01490451.2015.1080323
  15. Suosaari, E.P., Reid, R.P., Playford, P.E., Foster,J.S., Stolz, J.F., Casaburi, G., Hagan, P.D., Chirayath, V., Macintyre, I.G., Planavsky, N.J., and Eberli, G.P. 2016. New multi-scale perspectives on the stromatolites of Shark Bay, Western Australia.Sci. Rep. | 6:20557 | DOI: 10.1038/srep20557.
  16. Mason, D.M., Nouraei, N., Pant, D.B., Miner K.M., Hutchison, D.F., Luk, K.C., Stolz, J.F., and Leak, R.K. 2016. Transmission of a-synucleinopathy from olfactory structures deep into the temporal lobe. Mole. Neurodegen. 11:49 DOI: 10.1186/s13024-016-0113-4.
  17. Lampe, D.J., and Stolz, J.F. 2015. Environmental impacts of unconventional shale gas extraction in the Appalachian Basin. Environ Sci and Health, Part A 50:434-446.
  18. Alawattegama, S., Kondratyuk, T., Krynock, R., Bricker, M., Bain, D., and Stolz, J.F. 2015. Well water contamination in a rural community in Southwestern PA with unconventional shale gas extraction. Environ Sci and Health, Part A 50:516-528.
  19. Dheer, R., Patterson, J., Dudash, M., Nmezi, B., Stolz, D.B., Stachler, E., Bibby, K., Barchowsky, A., and Stolz, J.F. 2015. Arsenite induced changes in the microbiota of the murine colon. Toxicol Appl Pharmacol. 2893:397-408. doi: 10.1016/j.taap.2015.10.020.


John Stolz received his BS degree in biology from Fordham University in 1977. He earned his PhD from Boston University in 1984 in microbial ecology and evolution studying community structure in stratified microbial mats. He then took a position as an NRC Post doctoral fellow at the NASA Jet Propulsion Laboratory and Visiting Faculty in the Department of Geology and Planetary Sciences, California Institute of Technology, where he studied magnetotatic bacteria and biomagnetism. This was followed by an NSF Postdoctoral Fellowship in Plant Biology in the Biochemistry Department at the University of Massachusetts, Amherst, where he studied photosynthesis in green bacteria. Joining the faculty at Duquesne University in 1990 he continued research on microbial community structure and began studies on anaerobic respiration. He received the Bayer School Award for Excellence in Scholarship in 1996 and 2008, and Excellence in Service in 2014. He received the Presidents Award for Excellence in Scholarship in 1997 and 2008, and Excellence in Service in 2014. He was appointed the Nobel J. Dick Endowed Chair for Community Outreach in 2015.

  • Arsenic
  • Selenium
  • Microbial Ecology
  • Biogeochemistry
  • Environmental Science