Professional Preparation
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- 1974 Biology , Bloomfield College
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- 1976 M.S. in Mycology , University of South Carolina
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- 1981 Ph.D. in Microbiology, Microbial Ecology , University of South Carolina
Appointments
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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
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Jan 1994 to
Present
Professor
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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
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Jan 1987 to
Present
Assoc Prof
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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
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Jan 1981 to
Present
Assist Professor
Research and Expertise
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The feeding behavior of protozoan predators is altered by the food quality of preyFood 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.
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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
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{Journal Article }
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.
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{Journal Article }
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
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{Journal Article }
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)
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Foster, B.L.L. and T.H. Chrzanowski. 2012. A simple defined medium for growth and maintenance of the mixotrophic protist Ochromonas danica. Journal of Microbiological Methods. doi:10.1016/j.mimet.2011.12.016.{Journal Article }
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Foster, B.L.L. and T.H. Chrzanowski. 2012. The mixotrophic protist Ochromonas danica is an indiscriminant predator whose fitness is influenced by prey type. Aq. Microb. Ecol. 68:1-11..{Journal Article }
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Chrzanowski, T.H. and R.L. Smith. 2012. Validation of an adenylate kinase-amplified bioluminescence method for qualitative detection of contamination of betamethasone suspension. Am. Pharma. Rev. http://www.americanpharmaceuticalreview.com/Specialty/Microbiology/Featured-Articles/126959-Validation-of-an-Adenylate-Kinase-amplified-Bioluminescence-Method-for-the-Rapid-Detection-of-Contamination-in-a-Betamethasone-Suspension/{Journal Article }
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Grover JP Chrzanowski TH. 2009. Dynamics and nutritional ecology of a nanoflagellate preying upon bacteria. Microbial Ecology 60:231-243.{Journal Article }
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Molina-Kappell G, Grover JP, Chrzanowski TH. 2009. Micro-scale surface-patterning influences biofilm formation. Elect. J. Biotech. 12(3).{Journal Article }
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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 }
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Journal Article
2014
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Journal Article
2013
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Journal Article
2012
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Journal Article
2009
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Journal Article
1999
Support & Funding
This data is entered manually by the author of the profile and may duplicate data in the Sponsored Projects section.-
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May 2011 to
Present
Equivalence verification of bioluminescence-based assay technologies. sponsored by
- $42000
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May 2011 to
Present
Equivalence verification of bioluminescence-based assay technologies. sponsored by
- $42000
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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
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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
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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
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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
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Jan 2005 to
Present
Dispersion of fungal spores and assessment of growth in ophthalmic preparations. sponsored by
- $40000
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Jan 2005 to
Present
The impact of variable stoichiometry on predation and competition: Development of microbial experimental models. sponsored by
- $332781
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Jan 2005 to
Present
Dispersion of fungal spores and assessment of growth in ophthalmic preparations. sponsored by
- $40000
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Jan 2001 to
Present
Kinetics of algal growth in metroplex reservoirs: Bioassay experiments on summertime populations. sponsored by
- $19358
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Jan 2001 to
Present
Water quality issues: Real-time assessment of nutrients in aquatic systems. sponsored by
- $104550
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Jan 2001 to
Present
Kinetics of algal growth in metroplex reservoirs: Bioassay experiments on summertime populations. sponsored by
- $19358
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Jan 1997 to
Present
Microbial indicators of biological integrity and nutrient stress for aquatic ecosystems. sponsored by
- $750000
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Jan 1997 to
Present
Microbial indicators of biological integrity and nutrient stress for aquatic ecosystems. sponsored by
- $750000
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Jan 1993 to
Present
Research Experiences for Undergraduates: Supplement to Trophic structure and the stoichiometry of nitrogen and sponsored by
- $5000
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Jan 1993 to
Present
Research Experiences for Undergraduates: Supplement to Trophic structure and the stoichiometry of nitrogen and sponsored by
- $5000
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Jan 1992 to
Present
Research Experiences for Undergraduates: Supplement to Trophic structure and the stoichiometry of nitrogen and sponsored by
- $4750
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Jan 1992 to
Present
Trophic structure and the stoichiometry of nitrogen and phosphorus in the pelagic food web. sponsored by
- $400000
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Jan 1992 to
Present
Research Experiences for Undergraduates: Supplement to Trophic structure and the stoichiometry of nitrogen and sponsored by
- $4750
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Jan 1981 to
Present
Metabolic studies on the bacterioneuston of a freshwater lake. sponsored by
- $8000
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Jan 1981 to
Present
Metabolic studies on the bacterioneuston of a freshwater lake. sponsored by
- $8000
Courses
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BIOL 3444-001GENERAL MICROBIOLOGYDescription of the course and learning outcomes: 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.
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BIOL 3328-001Environmental MicrobiologyMicrobes, 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.
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BIOL 5351-001ENVIRONMENTAL MICROBIOLOGYMicrobes, 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.
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Other Service Activities
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Uncategorized
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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
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May 2013 Professional Activities, Scholarly:
Ad hoc referee for several professional journals and for national granting agencies.
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May 2013 Associations:American Society for Microbiology, American Society for Limnology and Oceanography
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by Inknowledge Mentis, an open enterprise system.