Over the summer, we highlighted several undergraduates and their summer research at Caltech. Some were Techers; others hailed from schools across the country. Most participated in the Summer Undergraduate Research Fellowships (SURF) program, a unique opportunity for undergraduates to spend 10 weeks over the summer doing original research with Caltech faculty. This is the final profile of our summer research series.
Their summer research is about to take a group of Caltech undergrads SURFing across the country for a global competition. The students, gold medal winners in last month's International Genetically Engineered Machine (iGEM) regional contest, are headed to MIT this weekend for the world championship jamboree.
The annual iGEM competition, which began in 2003, is an undergraduate synthetic-biology competition that challenges students to build biological systems and operate them in living cells. The Caltech team, which includes four Techers and one student from California State University, Los Angeles, spent the summer working on the bioremediation of endocrine-disrupting chemicals (EDCs) in water as part of the SURF program. EDCs mimic or block hormones, such as estrogen, and cause adverse effects, such as development and reproductive disorders, in humans and other animals. Bioremediation uses microorganisms that eat toxic compounds and convert them into water and harmless gasses.
In the lab of Richard Murray, Everhart Professor of 
Control & Dynamical Systems and Bioengineering, the students worked with graduate co-mentors to create a bioremediation system in Escherichia coli that could degrade at least one EDC.
"We envisioned E. coli expressing a degradation protein, growing in a biofilm on some substrate packed in a column, and then being able to flow EDC-contaminated water through the column and have decontaminated effluent at the other end," says Amanda Shelton, a Caltech sophomore on the team.
First, the team pinpointed a gene called DDT dehydrochlorinase—which can degrade the pesticide DDT—in fruit flies.
"When we optimized this gene for expression in E. coli, we found that it retained its functionality, which is exciting because that means this new tool can be used by synthetic biologists in a simple model organism," says team member Nikki Thadani, a senior bioengineering student.
Next, in the lab of Frances Arnold, Dickinson Professor of Chemical Engineering, Bioengineering and Biochemistry, they were able to identify some enzymes that can initiate the degradation of bisphenol A (BPA), a chemical used primarily to make plastics. The group also gathered biological samples from the highly polluted Los Angeles River.
"We found that organisms cultured from the L.A. River could grow in the presence of endocrine disruptors as the only carbon source, indicating that these organisms can possibly degrade endocrine disruptors," says Thadani. "If we can conclusively show that the organisms in these cultures are degrading endocrine disruptors, then we can try and isolate the genes that allow them to do this."
Although the research was carried out over the summer, the planning process started last fall after the completion of the 2010 iGEM competition. The group met regularly throughout the school year to brainstorm ideas with Murray and the graduate mentors.
"Since we chose our projects and mentors, we genuinely cared about our work and were proud to complete it," says Puikei Cheng, now a sophomore at Caltech. "SURF provides a good introduction to any field of interest, even if someone has no background in lab techniques or scientific research."
In fact, at the start of the project, four of the five team members were freshmen doing research for the first time.
"It was really exciting and rewarding to see our hard work win us a gold medal at the iGEM regionals and a trip to the international conference in Boston," says Cheng. "We're hoping to see what interesting projects iGEM teams around the world have done over the summer. We're keeping our eyes open for good ideas for next year."
The iGEM World Championship Jamboree will be held November 5–7 at MIT. For more information on the team's research, visit their iGEM wiki.
Written by Katie Neith