Professor of Biology Colleen M. Cavanaugh loves bacteria.

She's especially fond of the organisms that live inside undersea tube worms, existing on sulphur filtering out of deep-sea thermal vents.

Now in her 16th year at Harvard, Cavanaugh, who came to Cambridge as a graduate student and was tenured last February, has spent most of her professional life studying marine ecology.

In graduate school, Cavanaugh spoke up during a colloquium to propose the theory that bacteria live symbiotically within tube worms, metabolizing chemicals to stay alive.

The implications of this idea proved far-reaching, and scientists are still studying such symbiotic relationships.

"By looking at synthetic systems, we can understand eukaryotic forms," Cavanaugh says.

Today, Cavanaugh and her 11 student research assistants--post-doctoral fellows, graduate students and undergraduates--are pursuing several interrelated projects, including the diversity of symbiotes within the vents and the ecology of the carbon dioxide-fixing enzyme RuBisco.

But Cavanaugh is always looking for new avenues of research.

"We have a zillion little projects," she says.

The professor personally presides over all activities in the Cavanaugh Lab and is present in every decision, students say. The atmosphere of scientific congeniality is notable.

"She is a very enthusiastic, involved person," says Benjamin C. Kirkup '96, who is working on a phylogenetic analysis of RuBisco in the lab. "She has her hand in everything and is on top of all aspects of the lab."

Kirkup praises his mentor's involvement in the projects of her students.

"She is very concerned about people falling through the cracks, and is not only concerned for the lab work and science but also for the education and career development of all the lab personnel," he says.

For her part, Cavanaugh says students are her favorite aspect of the University.

"The best thing is the students," she says. "The undergrads are just amazing."