Dr. Cecilia Batmalle Kretz, PhD

In my third year at Ryerson I volunteered to work for my microbiology professor, Dr Kim Gilbride. It was very rewarding and exciting to work on my own project with my own goals and expectations. My project involved using bioreactors to compare the DNA content in biofilms contained in waste water over a period of two weeks. We also used confocal microscopy to quantify cells in the bioreactor over the same time frame. This project gave me my first responsibility as a researcher and opened my mind to creating my own experimental procedures, changing my protocols, and adapting to inevitable changes during experiments.

At the end of that year, I moved with my parents to Australia where I obtained my Bachelor in Science degree from Australian National University. After finishing my Bachelor degree, I also completed  a year-long Honours program, which required conducting research and presenting a thesis. In my Honours project I investigated the advantages accruing from producing multiple bacteriocins, implemented competitive experiments between different bacterial strains from single and multiple producers, collected relevant data, and performed growth rate experiments. The main goal of my project was to determine which strains would have an environmental and ecological advantage over other strains. The final goal would be to use those strains that have a fitness advantage as antimicrobial agents. We discovered that multiple bacteriocin carriage confers a selective advantage to cells producing more than one type of bacteriocins. Since I was also able to work on this project independently with support from my supervisor, Dr. David Gordon and the lab crew, I learned to reason in a scientifically analytical manner while also coming to understand that experiments do not always work out the way we hope they would. Patience and hard work are therefore crucial to successful research. Based upon this experience I decided to pursue doctoral studies in microbiology.

After graduating from ANU, I was unsure how to direct my research interests towards a fulfilling career. I was debating between the medical field and the ecological and evolution field. For this reason, I decided to gain more experience in the medical field. After moving to Los Angeles, joined a volunteer program at the Center for Health Sciences at UCLA where I conducted research under Dr. Vladana Milisavljevic and Dr. Jeff F. Miller. Since some of my interests were in medically-oriented microbiology research, I was very pleased to be part of a project involving the determination of pathogenesis and virulence of Staphylococcus epidermidis. Given certain specific environmental factors, S. epidermidis can cause clinical infection through biofilm production. We planned different sets of experiments, such as identifying the potential genes and proteins involved in the clinical infection and biofilm production. Once the genes were identified, we determined the pathways involved in biofilm production. Finally, we examined the interactions among host-bacteria infections in vivo and in vitro. However this research did not fulfill my questions of interest in biology and I decided to go back into environmentally oriented research. I immediately saw the opportunity to apply my fundamental knowledge of science and molecular biology to the study of microbial ecology. This provided a very challenging, but rewarding opportunity to use my molecular tools and creative thinking skills to attack complex, multidisciplinary questions such as: How do microbial community structure and diversity influence ecosystem processes? And how will global change affect microbes and the ecosystem processes they mediate?