This page is no longer being updated and remains online for informational and historical purposes only. The information is accurate as of the last page update.
For questions about page contents, contact the Communications Division.
Scott Crown ’08 (Effort, Pa.) is a chemical engineering major and Marquis Scholar conducting honors thesis research this school year. He is exploring the effects of particles called reverse micelles on proteins living in high salt concentrations, with Patricia Darcy, assistant professor of chemical engineering, serving as his adviser. The following is a first person account of his research.
A reverse micelle is a dispersion of oil, water, and surfactant consisting of nanometer–sized aqueous droplets, encapsulated by a surfactant monolayer. Reverse micelles can serve as hosts for protein molecules, such as enzymes. Enzymes in reverse micelles can function in harsh industrial conditions, remain active in low-water systems, aid in waste remediation, and act as detergent agents. In addition, the reverse micelle interface acts similar to water adjacent to biological membranes and provides an excellent model for many life processes.
My thesis project is examining the catalytic activity of a nonhalophilic enzyme and its halophilic counterpart in reverse micelles. Halophilic enzymes are found in highly saline environments, such as the Great Salt Lake and the Dead Sea. They require very high levels of salt to function; however when introduced into reverse micelles they can survive and remain active at very dilute salt contents. I will be examining the effects of salt type and concentration, the ratio of water to solvent concentration, and the pH on the enzymatic activity.
The day-to-day work of the project involves preparing the reverse micelle systems, cultivating and purifying the halophilic enzyme, and assaying the enzymatic activity. Due to the sensitive chemical structure of proteins, the most challenging part is the chromatography procedure for purification of the enzyme. The problem is two-fold: I need to verify that the enzyme I obtain is what I desire and in doing so the enzyme cannot denature or its function is deactivated.
Prior EXCEL research with Professor Darcy and a summer Research Experience for Undergraduates at Penn State University have exposed me to the methods of experimental research. From my experiences I have seen the uniqueness of the EXCEL Scholars program. The best aspect of the EXCEL program is that it develops the undergraduate student because it focuses on teaching the appropriate methodology and techniques to the research process rather than just obtaining the results.
My thesis work enables me to apply what I have learned to a self-guided project. Professor Darcy supplied me with the idea and I conducted the literature review to gain background information in order to choose the enzyme and reverse micelle system and the independent variables to be examined. Afterwards, I began to plan a series of experiments.
The hardest part for me is time management because it is hard to predict the duration of a series of experiments and sometimes weeks of research can be wasted when the results obtained are flawed. In addition, I have learned the importance of documentation from the background search to the materials and methods in the laboratory. The project has a plethora of information and in order to remain focused and not waste time, it is essential to be organized.
As a whole, the thesis project provides me with a great learning opportunity, which will be beneficial as I attend graduate school and pursue my Ph.D. in chemical engineering.
Crown’s EXCEL research with Darcy helped him become one of 12 students from across the country to participate in the National Science Foundation Research Experience for Undergraduate program in biomolecular engineering at Penn State last summer. He presented the results of two projects he worked on with Darcy at the American Institute of Chemical Engineers’ 2007 Annual Meetings in 2006 and 2007.
Crown was selected for Honorable Mention in mathematics, science, and engineering in the 2007 Barry Goldwater Scholarship Competition. He also spent a semester abroad in Bremen, Germany, with five other Lafayette students, studying engineering, German language, literature, and politics.