Profile
Educational Background
PhD, Bacteriology, University of Idaho, 1989
BS, Microbiology, The Pennsylvania State University, 1984
Research Interests
Research in my lab is focused on environmental microbiology, specifically survival of stress. When we examine the world around us, it is possible to see microbial communities living in surprising places. While many of these microbial communities do not live in so-called extreme environments, they still must survive stressful conditions. These conditions include exposure to UV light, desiccation, and nutrient limitation. In many cases, microbes must not only survive these natural stresses, but also in the presence of manmade stressors in the form of xenobiotic compounds (pollutants) that we release into the environment. It is the mechanisms and strategies used by microbes to survive these conditions that my laboratory is interested in understanding. Our examination of these strategies uses several systems to ask the question: What are these microbes producing to survive these conditions and how do they use these materials to survive in these stressful environments?
Our first study system is from the deserts of southeast and south-central Utah. This microbial ecosystem resides in the surfaces of exposed sandstones and is technically a cryptoendolithic microbial community (living within the pores). We have determined that these communities stabilize the surfaces of these sandstones, which are highly erodible. Further work by my group is examining the role of extracellular materials with regard to the binding and stabilization of iron(II). Our hypothesis is that microbes and light reduce iron(III) to iron(II), making it mobile in the environment. The ferrous iron (iron(II)) is then bound by an extracellular polysaccharide (EPS) that binds and stabilizes it, preventing its re-oxidation to ferric iron (iron(III)). Once bound it is then taken up by the surrounding microbial community where it is used in photosynthesis and other metabolic processes. Recent work from our lab has shown that when multiple samples are analyzed for diversity, a limited number of organisms form what seems to be a core community associated with specific sandstone formations. We examined two different sandstone types (the Entrada and the Navajo) in the Grand Staircase-Escalante National Monument in Utah and found that both types of sandstone harbored about 2000 different bacteria. Within each sandstone community, around 50-75 bacteria were found in both samples. While the field sites were only separated by about 7 kilometers, we found that only 11 species of bacteria were found to be in both bacterial communities, suggesting that the structure and chemistry of the sand stones are intimately involved in controlling the assembly of these communities. Additionally, we found that both communities produced an EPS that bound and concentrated a number of different divalent cations, making them more available to the residents of the community. Based upon the diversity profiles, we think that a cyanobacterium, known as Chroococcidiopsis, is the most likely candidate for the production of this EPS. The diversity profiles indicated that the genus Acidiphilium comprised between 3 and 10% of the total population of bacteria in these communities. This genus has species that are capable of reducing iron(III) to iron(II) under mildly acidic and aerobic conditions, providing us with a better explanation for the concentrations of iron(II) we have measured in these habitats. Currently, we are attempting to enrich for and isolate members of the Acidiphilium genus from this environment.
We have completed a series of studies examining the microbial diversity and ecology of South Carolina beaches. With the exception of beaches heavily impacted by large pollution events, little is known regarding the microbial ecology of these systems and the services that they provide to the near shore and estuarine marine ecosystem. New data are showing high levels of inorganic nitrogen compounds and ferrous iron. Microbiologically, we have detected members of the Planctomycetales, specifically those that are likely involved in nitrogen cycling. Ultimately we hope to link beach ecosystems to key ecological processes and issues associated with coastal life. We have found that the beaches in our study harbored a diverse array of bacteria that seemed to change on a seasonal basis. One of the beaches examined was heavily impacted by Hurricane Michael and required remediation via a beach renourishment process. Our data suggest that replenishing the beach using offshore sediments drastically changes the structure of the microbial communities, at least on a temporary basis. Other questions we are interested in addressing include: Does the iron found in these beaches serve to fertilize the near shore ecosystem? Is the overall diversity found in a beach ecosystem stable over many years? Are all SC beaches similar in their microbial diversity profiles? If not, what are the underlying parameters driving these differences? Are there any links (i.e. metals) between beach systems and the development of resistance in problematic bacteria found in the vicinity?
Courses Taught
Current Course:
Bacterial Physiology (MICR 4120/6120)
Microbiology Core I (MICR 8000, formerly 8040)
Advanced Microbiology Lab 1 (MICR 4500/4501)
Advanced Microbiology Lab II (MICR 4510/4511)
Previous Courses:
Soil Microbiology (MICR 4100/6100)
Understanding Microbiology (BIOL 8470)
Microbial Ecology and Diversity (MICR 4010)
Introductory Biochemistry (BCHM 3050)
Genes to Proteins (BCHM 4350)
Selected Publications
Taylor, H. B., Kurtz, Jr., H. D. (2020). Composition, diversity, and activity of aerobic ammonia-oxidizing Bacteria and Archaea in the intertidal sands of a grand strand South Carolina beach. MICROBIOLOGYOPEN DOI: 10.1002/mbo.1011
Taylor, H. B., Kurtz, Jr, H. D. (2020). Microbial community structure shows differing levels of temporal stability in intertidal beach sands of the grand strand region of South Carolina. PloS one, 15(2), e0229387 DOI: 10.1371/journal.pone.0229387
Sukhpreet Kaur and Harry D. Kurtz, Jr. (2018) Core bacterial community composition of a cryptoendolithic ecosystem in the Grand Staircase-Escalante National Monument, Utah, USA. MicrobiologyOpen. DOI: 10.1002/mbo3.707 I
Erik Hammes, Matthew Floyd, and Harry D. Kurtz, Jr. (2013). An Iron(II) Binding EPS and an Assessment of Microbial Diversity in Association with the EPS: Implications for Iron Cycling in the Jurassic Navajo Sandstone Journal of Arid Environments 97:49-55. ePub: htp://dx.doi.org/10.1016/j.aridenv.2013.05.006
Vijai Elango, Harry D. Kurtz, Jr., Christina Anderson, and David L. Freedman. (2011). Use of γ- hexachlorocyclohexane as a terminal electron acceptor by an anaerobic enrichment culture. Journal of Hazardous Materials 197:204-210.
Vijai Elango, Harry D. Kurtz, Jr., David L. Freedman. (2011). Aerobic cometabolism of trichloroethene and cis-dichloroethene with benzene and chlorinated benzenes as growth substrates. Chemosphere 84:247-253.
Huifeng Shan, Harry D. Kurtz, Jr., Nadia Mykytczuk Jack T. Trevors and David L. Freedman. (2010). Anaerobic Biotransformation of High Concentrations of Chloroform in Groundwater by an Enrichment Culture and Two Isolates, Applied and Environmental Microbiology 76:6463-6469
Kurtz, Jr., H. D. and Rosemary Cox. (2010). Microbial biofilm effects on local microconditions (cm scale) in Arid Environments and Their Potential Involvement in Iron Geochemistry, Proceedings of the Learning from the Land: Grand Staircase-Escalante National Monument Science Symposium, September 12-14, 2006, Cedar City, Utah. Published by Grand Staircase-Escalante Partners, UT
Shan, Huifeng, H.D. Kurtz, Jr., and D. L. Freedman. (2010). Evaluation of strategies for anaerobic bioremediation of high concentrations of halomethanes. Water Research 44:1317-1328.
Haddadin, Fu’ad T., Harry Kurtz, and Sarah W. Harcum. (2009). Serine hydroxamate and the transcriptome of high cell density recombinant Escherichia coli MG1655. Applied Biochemistry and Biotechnology 157:124-139 {Online info: DOI 10.1007/s12010-008-8241-0}
Toh, E, H. D. Kurtz, Jr., and Y. V. Brun. (2008). Characterization of the Caulobacter crescentus Holdfast Polysaccharide Biosynthesis Pathway Reveals Significant Redundancy in the Initiating Glycosyltransferase and Polymerase steps. Journal of Bacteriology 190(21):7219-7231
Selected Talks
Extracellular Polysaccharides of Cryptoendolithic Biofilms Concentrate Metals in an Oligotrophic Environment. Presented at the 2018 International Conference of Heavy Metals in the Environment, Athens, GA.
Microbial Communities of the Jurassic Navajo Sandstone & Their Role in Shaping the Landscape. Presented at the Grand Staircase-Escalante National Monument’s Science Forum, GSENM Visitor's Center, Escalante, UT, August 2016.
Microbial Diversity and Iron Cycling in the Cryptoendolithic Habitats in the Desert Southwest. Presented at the School of Public Health, University of South Carolina, Columbia, SC on November 4, 2015
The Microbiology of Desert Ecosystems: Can We Use these Ecosystems to Model Mars? Presented at Tri-County Technical College, October 9, 2013.
Microbes in Unusual Places: Their Effects on the Landscape. Presented at the 2012 Fall Meeting of the SC Branch of the American Society for Microbiology.
Memberships
American Society for Microbiology (ASM)
South Carolina Branch of ASM
Geology Society of America (GSA
