Studies of the Ammonium in the Biochemistry, Metabolism, and Host Cell Interactions of Trichomonads

Document Type



Under the Eugene M. Lang student/faculty research fellowship, I pursued studies in the significance of arginine and ammonium to the metabolism of trichomonads, Trichomonas foetus, a cattle strain and Trichomonas vaginalis, a human strain. Both parasites obtain energy by metabolizing arganine to ammonia in the arginine dihydrolase pathway. I demonstrated for the first time that the rate of metabolite flow through the arginine dihydrolase pathway can be determined by the measurements of ammonium ions or volatile ammonia production by cells. The specific mechanism of production ammonia remains to be determined. Our studies demonstrated that trichomonads thrive in high concentrations of ammonium that would be toxic to the tissues of their mammalian hosts.

Information about the Student Author

Class of 2004, Major: Biology

Summary of Research Experience

The opportunity to do research at the Haskin's Laboratory at Pace University helped me advance my understanding and skills of the laboratory techniques. I received training in diverse research methods, such as: cell culture methodology with parasites,aseptic techniques, microanalysis, instrumental techniques, enzyme kinetics. In addition, I learned to work under anaerobic conditions and with caustic chemicals. Methods developed in this study proved useful in clarifying an overlooked aspect of protozoan metabolism. I shared the results of this research project at the spring 2003 meeting of The Society of Fellows in the Dyson College of Arts and Sciences at Pace. Over the years of my undergraduate study, I have been able to participate in research that increased my knowledge of infectious diseases. By far, this research has made a difference in my understanding of the underlying concepts of the biochemical reactions of the microbial world. The knowledge gained through this research experience will tremendously aid me in my future work in the field of medicine. I gained further insight into the microbial world by presenting results of these ongoing studies at the 11th East Coast Conference on Protozoology (Baltimore, MD), and as a co-author of a presentation at the International Conference on Anaerobic Protists (Hilo, Hawaii). A manuscript, (Kleydman, Yekaterina; Gorrell, Thomas; Yarlett, Nigel. Production of ammonia by T. foetus and T. vaginalis, is being prepared for submission to a peer review journal. I would like to thank my mentors, Dr. Thomas Gorrell and Dr. Nigel Yarlett. They are superb teachers, and I am grateful for their support, time, and expertise on the subject matter. I wish to express my thanks to all of the members of the Haskin's Laboratory as well. Finally, I thank the Eugene M. Lang Foundation for giving me the opportunity to gain knowledge about one of the most prevalent parasitic diseases in the western world. The results will provide the scientific community with a greater understanding of the contribution of arginine and ammonia to the energy metabolism of parasitic trichomonads.

Faculty Mentor

Nigel Yarlett, Ph. D.; Professor of Chemistry and Physical Sciences and Thomas Gorrell, Ph.D., Associate Professor of Biological Sciences

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