Skip to content. Skip to main navigation.

avatar

Thomas Chrzanowski

Name

[Chrzanowski, Thomas]
  • Professor

Professional Preparation

    • 1974 Unknown degree in BiologyBloomfield College
    • 1976 M.S. in MycologyUniversity of South Carolina
    • 1981 Ph.D. in Microbiology, Microbial EcologyUniversity of South Carolina

Appointments

    • Jan 1994 to Present Professor
      University of Texas at Arlington   Office of the President   Office of the Provost and Vice President for Academic Affairs   College of Science   Department of Biology
    • Jan 1987 to Present Assoc Prof
      University of Texas at Arlington   Office of the President   Office of the Provost and Vice President for Academic Affairs   College of Science   Department of Biology
    • Jan 1981 to Present Assist Professor
      University of Texas at Arlington   Office of the President   Office of the Provost and Vice President for Academic Affairs   College of Science   Department of Biology

Research and Expertise

  • The feeding behavior of protozoan predators is altered by the food quality of prey
    Food quality has been shown to influence greatly the rate at which metazoan herbivores exploit prey (Sterner et al. 1993). Daphnia, feeding upon Scenedesmus whose element composition was altered by regulating growth conditions, was found to have lower clearance and feeding rates when food quality was poor. Lower clearance rates and feeding rates were associated with longer gut-passage times for poor-quality food-items. Similar predator-prey associations exist in microbial food webs where protozoan predators feed almost exclusively upon bacterial prey. However, analogous studies of predator-prey food quality interactions are lacking due to the technical difficulty working with protozoans that are mixotrophic or obligate bacterivores. The flagellate protozoan Ochromonas may be grown heterotrophically and will grow exclusively on bacteria. In many varieties, autotrophic growth is exceptionally poor. In this work, axenic Ochromonas danica is fed bacterial prey (Pseudomonas fluorescens) of known food quality (as C:N:P ratio). Ingestion, digestion, and clearance rates are determined for the protozoan during short term feeding experiments. Ultimately, we seek to describe the relationships among food quality, feeding behavior, growth rate, and element excretion for this predator-prey couple. These data will be extended into multi-element predator prey models.
  • Nutrient recycling by predators affects the resource base of their prey and thereby exerts indirect effects of competition.
    The relationships among population dynamics, species interactions, and nutrient dynamics have long been of interest to ecologists. Some two decades ago, Pomeroy (1976) established that active populations of heterotrophic bacteria and protozoa contribute significantly to biomass and secondary productivity. Azam et al. (1983) further contradicted then prevailing views, by suggesting that heterotrophic bacterioplankton consume dissolved inorganic nutrients, instead of mineralizing them from organic forms. Placed in direct competition with bacteria for nutrients, phytoplankton would suffer growth limitation that might be partially relieved by nutrients recycled through protozoa that prey on bacteria. Since then, the view has emerged that competition for nutrients is sharpest in nutrient-poor systems, favoring competitively superior bacteria, and decreasing the relative abundance of algae. Bacterial losses to flagellates, or perhaps to viruses, are likely higher in productive systems, with high rates of nutrient recycling that enhance the abundance of algae. The dominance of bacteria that are largely inedible to planktonic metazoa in nutrient poor systems could then impoverish grazing food chains and reduce export production. Under this paradigm predation on bacteria and the associated nutrient recycling control the critical issue of whether energy and nutrients dissipate within a microbial food web, or flow to higher organisms. This research employs simple microbial foods webs to illuminate mechanisms and processes structuring open-water ecosystems. Our simplified food webs use two bacterial prey species and a single protozoan predator in replicated two-stage chemostat systems to address prey selection and nutrient regeneration by the protozoan predator. Bacterial prey are grown in the first stage of the coupled chemostat system. The growth conditions are set to create cells of known food quality (element composition). These cells are subsequently fed to a protozoan predator in the second stage of the coupled chemostat system and, through mass-balance approaches, the element composition of the predator and element recycling is determined. During more advance studies, the predator will be supplied with two prey species of differing food quality (element composition) and prey-selection and nutrient regeneration determined.

Publications

      Journal Article 2014
      • Chrzanowski, T.H. and B.L.L. Foster. 2014.  Prey element stoichiometry controls ecological fitness of the mixotrophic flagellate Ochromonas danica.  Aq. Microb. Ecol. 71:257-269.

        {Journal Article} [Refereed/Juried]

      Journal Article 2013
      • Rout, M.E., T.H. Chrzanowski, W.K. Smith, and L. Gough.  2013.  Ecological impacts of an invasive grass Sorghum halepense on native tallgrass prairie.  Biological Invasions15:327-339

        {Journal Article} [Refereed/Juried]
      2013
      •  Rout, M.E., T.H. Chrzanowski, T.K. Westlie, T.H. DeLuca, R.M. Callaway and W.E. Holben.  2012.  What makes a plant invasive can be a matter of microbes: Bacterial endophytes increase growth and ecological impacts of Sorghum halepense.  Am. J. Bot. 100:1-12 (Invited)

        {Journal Article} [Refereed/Juried]

      Journal Article 2010
      • Chrzanowski TH, Lukomski NC, Grover JP. 2010. Element stoichiometry of a mixotrophic protist grown under varying resource condition. Journal of Eukaryotic Microbiology 57:322-327.
        {Journal Article} [Refereed/Juried]
      2010
      • Simonds S, Grover JP, Chrzanowski TH. 2010. Element content of Ochromonas danica: A replicated chemostat study controlling growth rate and temperature. FEMS Microbiology Ecology.
        {Journal Article} [Refereed/Juried]

      Journal Article 2009
      • Grover JP Chrzanowski TH. 2009. Dynamics and nutritional ecology of a nanoflagellate preying upon bacteria. Microbial Ecology 60:231-243.
        {Journal Article} [Refereed/Juried]
      2009
      • Molina-Kappell G, Grover JP, Chrzanowski TH. 2009. Micro-scale surface-patterning influences biofilm formation. Elect. J. Biotech. 12(3).
        {Journal Article} [Refereed/Juried]
      2009
      • Rout ME Chrzanowski TH. 2009. Endophytic diazotrophs: The latest weapon of an exotic invasive grass. Plant and Soil 315:163-172.
        {Journal Article} [Refereed/Juried]

      Journal Article 2008
      • Chrzanowski TH Grover JP. 2008. Element content of Pseudomonas fluorescens varies with growth rate and temperature: A replicated chemostat study addressing Ecological Stoichiometry. Limnol. Oceanogr. 53:1242-1251.
        {Journal Article} [Refereed/Juried]

      Journal Article 2007
      • Shannon SP, Chrzanowski TH, Grover JP. 2007. Prey food quality affects flagellate ingestion rate. Microbial Ecology 53:66-73.
        {Journal Article} [Refereed/Juried]
      2007
      • Malone JH, Chrzanowski TH, Michalak P. 2007. Sterility and gene expression in hybrid males of Xenopus laevis and X. muelleri. PLoS One.
        {Journal Article} [Refereed/Juried]

      Journal Article 2006
      • Grover JP Chrzanowski TH. 2006. Kinetics of growth and ingestion in the “smallest zooplankton” – phagotrophic flagellates. Archiv fuer Hydrobiolo:467-487.
        {Journal Article} [Refereed/Juried]
      2006
      • Grover JP Chrzanowski TH. 2006. 2005 Seasonal dynamics of phytoplankton in two warn temperate reservoirs. J. Plankton Research 27:1-17.
        {Journal Article} [Refereed/Juried]

      Journal Article 2005
      • Chrzanowski TH Grover JP. 2005. Temporal Coherence in limnological features of two southwestern reservoirs. Lakes and Reservoir Management 21:39-48.
        {Journal Article} [Refereed/Juried]

      Journal Article 2004
      • Grover, J.P. and T.H. Chrzanowski. 2004. Limiting resources, disturbance and diversity in phytoplankton communities. Ecol. Monogr. 74:533-551
        {Journal Article} [Refereed/Juried]

      Journal Article 2001
      • Chrzanowski, T.H. and J.P. Grover. 2001. The Light:Nutrient ratio in lakes: A test of hypothesized trends in bacterial nutrient limitation. Ecol. Letters 4:1-5
        {Journal Article} [Refereed/Juried]
      2001
      • Chrzanowski, T.H. and J.P. Grover. 2001. Effects of mineral nutrients on the growth of bacterio- and phytoplankton in two southern reservoirs. Limnol. Oceanogr. 46:1319-1330.
        {Journal Article} [Refereed/Juried]

      Journal Article 2000
      • Grover, J.P. and T.H. Chrzanowski. 2000. Seasonal patterns of substrate utilization by bacterioplankton: Case studies in four temperate lakes of different latitudes. Aquat. Microb. Ecol. 23:85-95.
        {Journal Article} [Refereed/Juried]
      2000
      • Elser, J., R.W. Sterner, A.E. Galford, T.H. Chrzanowski, D.L. Findlay, K.H. Mills, M.J. Paterson, M.P. Stainton, and D.W. Schindler. 2000. Pelagic C:N:P stoichiometry in a eutrophied lake: Responses to a whole-lake food-web manipulation. Ecosystems 3: 293-307
        {Journal Article} [Refereed/Juried]

      Journal Article 1999
      • Simek, K., J. Armengol, M. Comerma, J.C. Garcia, T.H. Chrzanowski, P. Kojecka, M. Macek, J. Nedoma and V. Straskabova. 1999. Impacts of protistan grazing on bacterial dynamics and composition in reservoirs of different trophy. pp. 267-282. In: Tundis, M. and Straskrada, M. [eds.] Theoretical Resevoir ecology and its applications. Interntl. Inst. Ecol., Brazilian Acad. Sci. Backhuys Publishers.
        {Journal Article} [Refereed/Juried]

      Journal Article 1998
      • Elser, J.J., T.H. Chrzanowski, R.W. Sterner, and K.H. Mills. 1998. Stoichiometric constraints on food-web dynamics: A whole-lake experiment on the Canadian Shield. Ecosystems. 1:1-21.
        {Journal Article} [Refereed/Juried]
      1998
      • Lind, O.T., T.H. Chrzanowski, L. Davalos-Lind. 1998. Clay-turbidity and relative production of bacterioplankton and phytoplankton. Hydrobiologia. 353:1-18.
        {Journal Article} [Refereed/Juried]

      Journal Article 1997
      • Sterner, R.W., J.J. Elser, E.J. Fee, S. J. Guildford, and T.H. Chrzanowski. 1997. The Light:Nutrient ratio in Lakes: The balance of energy and materials affects ecosystem functioning. Am. Nat. 150:663-684.
        {Journal Article} [Refereed/Juried]

      Journal Article 1996
      • Chrzanowski, T.H., M. Kyle, J.J. Elser, and R.W. Sterner. 1996. Element ratios and growth dynamics of bacteria in an oligotrophic Canadian Shield lake. Aquatic Microbial Ecol. 11:119-125.
        {Journal Article} [Refereed/Juried]
      1996
      • Chrzanowski, T.H. and M. Kyle. 1996. Ratios of carbon, nitrogen and phosphorus in Pseudomonas fluorescens as a model for bacterial element ratios and nutrient regeneration. Aquat. Microbial Ecol. 10:115-122.
        {Journal Article} [Refereed/Juried]

      Journal Article 1995
      • Elser, J.J., T.H. Chrzanowski, R.W. Sterner, J.H. Shampel, and D.K. Foster. 1995. Element ratios and the uptake and release of nutrients by phytoplankton and bacteria in three lakes of the Canadian Shield. Microb. Ecol. 29:145-162.
        {Journal Article} [Refereed/Juried]

Support & Funding

This data is entered manually by the author of the profile and may duplicate data in the Sponsored Projects section.
    • May 2011 to Present Equivalence verification of bioluminescence-based assay technologies. sponsored by  - $42000
    • Jan 2008 to Present Evaluation of the Nuance Multispectral imaging system for identification and discrimination of particulates from viable microorganisms recovered from pharmaceutical solutions. sponsored by  - $28000
    • Jan 2006 to Present Comparison of microbial enumeration of metabolically stressed microorganisms in aqueous samples by Scan RDITM and Plate count methods. sponsored by  - $40000
    • Jan 2005 to Present Dispersion of fungal spores and assessment of growth in ophthalmic preparations. sponsored by  - $40000
    • Jan 2005 to Present The impact of variable stoichiometry on predation and competition: Development of microbial experimental models. sponsored by  - $332781
    • Jan 2001 to Present Kinetics of algal growth in metroplex reservoirs: Bioassay experiments on summertime populations. sponsored by  - $19358
    • Jan 2001 to Present Water quality issues: Real-time assessment of nutrients in aquatic systems. sponsored by  - $104550
    • Jan 1997 to Present Microbial indicators of biological integrity and nutrient stress for aquatic ecosystems. sponsored by  - $750000
    • Jan 1993 to Present Research Experiences for Undergraduates: Supplement to Trophic structure and the stoichiometry of nitrogen and sponsored by  - $5000
    • Jan 1992 to Present Research Experiences for Undergraduates: Supplement to Trophic structure and the stoichiometry of nitrogen and sponsored by  - $4750
    • Jan 1992 to Present Trophic structure and the stoichiometry of nitrogen and phosphorus in the pelagic food web. sponsored by  - $400000
    • Jan 1981 to Present Metabolic studies on the bacterioneuston of a freshwater lake. sponsored by  - $8000

Courses

      • BIOL 3444-001 GENERAL MICROBIOLOGY

        The objective of this course is to introduce you to the life of the prokaryote. From the perspective of both age and biology, this fabulously diverse group of organisms is unlike any other form of life on the planet. While widely known for their medical importance, these organisms also play important roles in maintaining our environment, supplying food and medicines, and as vehicles by which we may understand the expression of genetic information. The material that we will cover is broad and voluminous; fortunately, it is also interesting. Upon completion of the course of study you should understand the major differences between the types of cellular life on the planet, you should understand how prokaryote metabolism differs from the metabolism of cells with a nucleus, you should understand how antibiotics function, and you should be able to understand some fundamental aspects of how your body responds to infections.

        Fall - Regular Academic Session - 2017 Download Syllabus Contact info & Office Hours
      • BIOL 4345-001 MICROBIAL PHYSIOLOGY

        Description of the course and learning outcomes:  The goal of this course is to conduct an in-depth review of cellular structure, function, and regulation. You should be able to integrate information about cell function sufficient to develop and argument that defends a position.

        Fall - Regular Academic Session - 2017 Download Syllabus Contact info & Office Hours
      • BIOL 3444-001 GENERAL MICROBIOLOGY

        The objective of this course is to introduce you to the life of the prokaryote. From the perspective of both age and biology, this fabulously diverse group of organisms is unlike any other form of life on the planet. While widely known for their medical importance, these organisms also play important roles in maintaining our environment, supplying food and medicines, and as vehicles by which we may understand the expression of genetic information. The material that we will cover is broad and voluminous; fortunately, it is also interesting. Upon completion of the course of study you should understand the major differences between the types of cellular life on the planet, you should understand how prokaryote metabolism differs from the metabolism of cells with a nucleus, you should understand how antibiotics function, and you should be able to understand some fundamental aspects of how your body responds to infections.

        Spring - Regular Academic Session - 2017 Download Syllabus Contact info & Office Hours
      • BIOL 3328-001 Environmental Microbiology

        Microbes, while widely known for their medical importance, also play important roles in maintaining our environment, supporting agriculture, and maintaining the movement of critically important elements through the biosphere.  However, little emphasis is placed upon these topics in typical General Microbiology courses; consequently, the objective of this course is to introduce you to the life of microbes in their natural environments, some of the methods used to study mixed communities of microbes in nature, and how microbes impact upon human activities. 

        Upon completion of the course of study you should understand the nature of the environments where microbes exist and how they are dispersed from these environments, some of the role microbes play in maintaining environmental quality, the role of microbes in major biogeochemical cycles of critically important elements, and some of the consequences of human activities on the major biogeochemical cycles of critical elements.

        Spring - Regular Academic Session - 2017 Download Syllabus Contact info & Office Hours
      • BIOL 5351-001 ENVIRONMENTAL MICROBIOLOGY

        Microbes, while widely known for their medical importance, also play important roles in maintaining our environment, supporting agriculture, and maintaining the movement of critically important elements through the biosphere.  However, little emphasis is placed upon these topics in typical General Microbiology courses; consequently, the objective of this course is to introduce you to the life of microbes in their natural environments, some of the methods used to study mixed communities of microbes in nature, and how microbes impact upon human activities. 

        Upon completion of the course of study you should understand the nature of the environments where microbes exist and how they are dispersed from these environments, some of the role microbes play in maintaining environmental quality, the role of microbes in major biogeochemical cycles of critically important elements, and some of the consequences of human activities on the major biogeochemical cycles of critical elements.

        Spring - Regular Academic Session - 2017 Download Syllabus Contact info & Office Hours
      • BIOL 4345-001 MICROBIAL PHYSIOLOGY

        Description of the course and learning outcomes:  The goal of this course is to conduct an in-depth review of cellular structure, function, and regulation. You should be able to integrate information about cell function sufficient to develop and argument that defends a position.

        Fall - Regular Academic Session - 2016 Download Syllabus Contact info & Office Hours
      • BIOL 3444-002 General Microbiology

        The objective of this course is to introduce you to the life of the prokaryote.  From the perspective of both age and biology, this fabulously diverse group of organisms is unlike any other form of life on the planet.  While widely known for their medical importance, these organisms also play important roles in maintaining our environment, supplying food and medicines, and as vehicles by which we may understand the expression of genetic information.  The material that we will cover is broad and voluminous; fortunately, it is also interesting.

        Fall - Regular Academic Session - 2016 Download Syllabus Contact info & Office Hours
      • BIOL 3444-001 GENERAL MICROBIOLOGY

        The objective of this course is to introduce you to the life of the prokaryote.  From the perspective of both age and biology, this fabulously diverse group of organisms is unlike any other form of life on the planet.  While widely known for their medical importance, these organisms also play important roles in maintaining our environment, supplying food and medicines, and as vehicles by which we may understand the expression of genetic information.  The material that we will cover is broad and voluminous; fortunately, it is also interesting.

      • BIOL 3444-002 General Microbiology

        The objective of this course is to introduce you to the life of the prokaryote.  From the perspective of both age and biology, this fabulously diverse group of organisms is unlike any other form of life on the planet.  While widely known for their medical importance, these organisms also play important roles in maintaining our environment, supplying food and medicines, and as vehicles by which we may understand the expression of genetic information.  The material that we will cover is broad and voluminous; fortunately, it is also interesting.  Upon completion of the course of study you should understand the major differences between the types of cellular life on the planet, you should understand how prokaryote metabolism differs from the metabolism of cells with a nucleus, you should understand how antibiotics function, and you should be able to understand some fundamental aspects of how your body responds to infections.

        Spring - Regular Academic Session - 2016 Download Syllabus Contact info & Office Hours
      • BIOL 3327-001 MICROBIAL DIVERSITY

        General Microbiology introduced you to the prokaryotes and some of the aspects of their anatomy and physiology.  In this course of study you will be introduced to the great diversity of microbial life.   The topic material focuses attention on organisms not commonly encountered in general microbiology laboratories and explores this diversity by considering the great age of bacteria, their evolution, physiology, and habitats.  At the end of this course you should be able to understand bacterial photosynthesis and how it relates to other forms of photosynthesis, chemolithotrophic metabolism, concepts of electron donors and electron acceptors in metabolism, and the potential impact of microbial metabolism on the environment.

        Spring - Regular Academic Session - 2016 Download Syllabus Contact info & Office Hours
      • BIOL 4345-001 MICROBIAL PHYSIOLOGY

        The goal of this course is to conduct an in-depth review of cellular structure, function, and regulation. You should be able to integrate information about cell function sufficient to develop and argument that defends a position.

        Fall - Regular Academic Session - 2015 Download Syllabus Contact info & Office Hours
      • BIOL 3444-002 General Microbiology

        The objective of this course is to introduce you to the life of the prokaryote.  From the perspective of both age and biology, this fabulously diverse group of organisms is unlike any other form of life on the planet.  While widely known for their medical importance, these organisms also play important roles in maintaining our environment, supplying food and medicines, and as vehicles by which we may understand the expression of genetic information.  The material that we will cover is broad and voluminous; fortunately, it is also interesting. 

        Fall - Regular Academic Session - 2015 Download Syllabus Contact info & Office Hours
      • BIOL 3444-001 GENERAL MICROBIOLOGY

        The objective of this course is to introduce you to the life of the prokaryote.  From the perspective of both age and biology, this fabulously diverse group of organisms is unlike any other form of life on the planet.  While widely known for their medical importance, these organisms also play important roles in maintaining our environment, supplying food and medicines, and as vehicles by which we may understand the expression of genetic information.  The material that we will cover is broad and voluminous; fortunately, it is also interesting.

      • BIOL 5321-001 Environmental Microbiology

        The objective of this course is to introduce you to the life of microbes in their natural environment, some of the methods used to study mixed communities of microbes, and how microbes impact upon human activities. 

        Spring - Regular Academic Session - 2015 Download Syllabus Contact info & Office Hours
      • BIOL 3444-002 General Microbiology

        The objective of this course is to introduce you to the life of the prokaryote.  From the perspective of both age and biology, this fabulously diverse group of organisms is unlike any other form of life on the planet.  While widely known for their medical importance, these organisms also play important roles in maintaining our environment, supplying food and medicines, and as vehicles by which we may understand the expression of genetic information.  The material that we will cover is broad and voluminous; fortunately, it is also interesting.  You are expected to complete the course knowing enough about bacteria and viruses to carry on an intelligent conversation about the life of these amazing oganisms.

        Spring - Regular Academic Session - 2015 Download Syllabus Contact info & Office Hours
      • BIOL 3328-001 Environmental Microbiology

        The objective of this course is to introduce you to the life of microbes in their natural environment, some of the methods used to study mixed communities of microbes, and how microbes impact upon human activities. 

        Spring - Regular Academic Session - 2015 Download Syllabus Contact info & Office Hours
      • BIOL 4345-001 Microbial Physiology

        The goal of this course is to conduct an in-depth review of cellular structure, function, and regulation. You should be able to integrate information about cell function sufficient to develop and argument that defends a position.

        Fall - Regular Academic Session - 2014 Download Syllabus Contact info & Office Hours
      • BIOL 3327-001 Microbial Diversity

        The goal of this course is to introduce you to the great diversity of microbial life.   The topic material explores this diversity by considering the great age of bacteria, their evolution, biochemistry, habitat and form.  The course of study focuses attention on organisms not commonly encountered in General Microbiology laboratories.

        Spring - Regular Academic Session - 2014 Download Syllabus Contact info & Office Hours

Other Service Activities

  • Uncategorized
    • May 2013 Professional Activities, Educational:

      Undergraduate Courses: General Microbiology, Environmental Microbiology, Microbial Diversity, Microbial Structure and Function

      Graduate Couses: Ethics, Graduate Research, Microbial Structure and Function, Microbial Ecology

    • May 2013 Professional Activities, Scholarly:

      Ad hoc referee for several professional journals and for national granting agencies.

    • May 2013 Associations:
      American Society for Microbiology, American Society for Limnology and Oceanography