Department of Biological Sciences

Rachel Larsen Ph.D.

Lecturer of Biology
Rachel Larsen

Office Location

477 Science ("C" wing)



Academic Degrees

  • Ph.D., Microbiology, University of Illinois, Urbana-Champaign, 1999
  • M.S., Microbiology, University of Illinois, Urbana-Champaign, 1993
  • B.A., Biology, Vassar College, 1989


Dr. Larsen joined the Biology Department at USM in 2012 after a visiting faculty appointment at Bowdoin College. She held postdoctoral positions at the University of Illinois and Utah State University before working as a research scientist and teaching at the University of California, San Diego.

Dr. Larsen is a microbiologist with expertise in ecology and metabolism. She primarily teaches Microbiology for the Health Sciences (BIO 281), together with Microbiology lab (BIO 282). She occasionally teaches Microbial Ecology (BIO 415/515, 416/516), as well as a biology lab course for nonmajors (BIO 102).

Advisees and other students can make an appointment to meet with Dr. Larsen here.

Research Interests

I am interested in what native bacterial communities are doing to break down and grow on antibiotics, especially synthetic antibiotics like cipro and triclosan. These drugs are constantly introduced into the environment through wastewater, and it's not surprising that bacteria, which can be incredibly versatile, would learn how to utilize such molecules as food. Most studies focus on resistance to drugs rather than metabolism of drugs, so I am interested in how some bacterial species are not only resistant but also take advantage of these new and unusual food sources. I am also interested in how often species with such abilities can be isolated (from various sources) and how many different species have learned how to do this.