Recent high school graduate David Zimmerman stands at a bench in Steven Finkel’s laboratory preparing cultures of the bacterium Shewanella oneidensis — “Shewy” as he and others affectionately call it.
Zimmerman deftly sterilizes a test tube, passing it over the blue flame of a Bunsen burner. The 18-year-old carefully measures out culture medium with a pipette, fills the test tube, then swabs in a sample of Shewy.
One by one, the open slots in the nearby rack begin to fill up with tubes of live cultures.
Although young, Zimmerman blends in. He knows this experience gives him a substantial jumpstart in his scientific career. He graduated from Brentwood School in Los Angeles this spring, but began laboratory work at the tender age of 15 honing his scientific technique over the past three years under the guidance of Finkel, associate professor of biological sciences at USC Dornsife.
Zimmerman said the opportunity to be a part of a “real” lab has meant more to him than words can express.
“Entering high school, I had some inkling that I wanted to be a biologist, but I didn't really know what that meant,” Zimmerman said. “I knew well enough what biology was, but I didn't have a sense of what it meant to do — as opposed to study — biology.
“As it turns out, I can't imagine doing anything else, but I'd have had no idea if I hadn't been blessed with the chance to discover what a messy, exhausting and absolutely delightful business science actually is.”
Zimmerman’s own devotion to science and Finkel’s instruction was evident at the 2013 Los Angeles County Science Fair, the annual science and engineering fair for all middle and high school students in Los Angeles schools, and at the Intel International Science and Engineering Fair (Intel ISEF), the largest international pre-college science competition for students in grades 9 through 12.
At the Los Angeles County Science Fair held in Pasadena this March, he placed first in the microbiology category and was named Senior Sweepstakes winner, the fair’s top award, for his research on Shewanella.
As a result of his success at the regional science fair, Zimmerman was selected as one of two representatives from L.A. County to attend the Intel ISEF Science Fair in Phoenix, Ariz., in May.
At the Intel ISEF Science Fair, Zimmerman also received top recognitions for his research, taking home a total of four awards. He placed first in the fair’s microbiology category and was named “Best in Category” of the two first-prize winners in the category. He also received the first place American Society for Microbiology Award, honoring the most outstanding microbiology projects.
Finally, Zimmerman was one of three awardees of the Dudley R. Herschbach SIYSS Award. The Hershbach award recognizes remarkable achievements by young scientists from around the world. The prize comes with an invitation to attend the Stockholm International Youth Science Seminar (SIYSS) and the Nobel Prize ceremonies in Stockholm, Sweden.
“I’m still in disbelief,” Zimmerman said of his many achievements. “The main thing for me was getting to go to ISEF in the first place. I got to meet so many kids from all over the world who were doing spectacular work. I had such a wonderful time.”
His winning research focused on strategies for working with Shewanella in genetics research.
“We’re really interested in using Shewanella as a model system for studying electron transport processes that bacteria carry out,” Zimmerman said. “But a major obstacle for scientists who want to study Shewy is that members of the genus tend to be really difficult to manipulate using techniques of classical genetics.”
To overcome these obstacles, Zimmerman perfected the process of electroporation in Shewanella, a method of introducing a substance into a cell. In this case, he focused on adding DNA into Shewanella. He then discovered a way to mutate the chromosomes of the bacterium in a site-specific manner using short, single-stranded pieces of DNA.
“What David was able to do, which was so terrific, was read the scientific literature and see what was being done in other organisms and then translate that for Shewanella,” Finkel said. “He’s literally transforming Shewanella in a way that’s never been done before.”
The tools that Zimmerman developed expand the types of experimental manipulations that are possible with Shewanella. His methods also have the broader potential to apply to other bacteria that are recalcitrant to classical genetics.
Zimmerman has been participating in science fairs for many years. As a middle school student with a voracious appetite for learning, a teacher encouraged him to enter his first fair. That same teacher also nudged him to reach out to university professors for advice when he encountered technical challenges in his experiments.
Taking the teacher’s advice, Zimmerman contacted Ken Nealson, Wrigley Chair in Environmental Studies and professor of earth sciences and biological sciences at USC Dornsife, who eventually invited Zimmerman, 14 at the time, to work in his lab. He spent the summer assisting a graduate student.
During that time, Zimmerman became acquainted with the work of other USC Dornsife researchers, taking interest in Finkel’s research with Shewanella.
Finkel recalled the day when Zimmerman showed up at his office with a poster from the science fair he participated in during his high school sophomore year. “I looked at the poster and it was ridiculously good,” Finkel said, adding that Zimmerman’s questions were sophisticated.
“We sat down and started talking, and two hours later I said, ‘Yes, you can work here.’ ”
Finkel trained Zimmerman in fundamental microbiology techniques such as how to handle bacteria properly, the method for starting cultures and basic DNA manipulation techniques.
While Finkel advised Zimmerman in his work with Shewanella, he noted that Zimmerman came up with the ideas for his experiments and steered the course of his own research. As an active member of Finkel’s research team, Zimmerman attends lab meetings and presents his work alongside undergraduate, graduate and postdoctoral researchers.
“Steve has really nurtured my interest in his field,” Zimmerman said. “But the single most valuable thing I have taken away from my experience working in Steve’s lab is that he’s shown me what being a scientist entails.”
Zimmerman intends to publish an academic paper on his research findings at the end of the summer before he heads off to college. This Fall, he will attend Stanford in Palo Alto, Calif., with plans to continue studying science. Ultimately, he would like to pursue a career in higher education, teaching and conducting research.
He credits his experience working with Finkel and Nealson as central to his development as a scientist.
“There’s no possible way that I could be where I am today in terms of future ambitions and my accomplishments without their support and mentorship,” Zimmerman said.