Meet the molecular biologist shining light on the mysteries of bacterial “slime” 

When Dr. Georgia Squyres was an undergraduate with a love of math and physics, she found herself working in a biology lab. In this lab, Squyres soon learned she could apply her training in math and physics to studying the curiously unknown pockets of biology — which, it turns out, is most of biology. As Squyres said, “there are a lot of unknown unknowns in biology. Many more than known unknowns.” In particular, the lab Squyres worked in was studying biofilms, complex communities of bacteria that work together to play different roles, held together by an intercellular matrix that often presents as “slime.”

One of those unknowns was exactly how to effectively study the roles individual cells play within biofilms. At that time, however, science, technology and Squyres’ own lab skills hadn’t developed enough to answer the questions she wanted to ask. So during her PhD, Squyres veered away from studying these mysterious slimes, though the unknowns remained in the back of her mind as she learned research science skills like microscopy, coding for biological research, and “a lot more math.”

Just as she was finishing her PhD armed with new insights and skills, new methods for studying biofilms were being published. “And so I was straight back in,” Squyres said. “The time was now to finally answer these questions.” Today, as a postdoctoral researcher in the Newman Lab at Caltech, Squyres studies biofilm development in an infectious disease organism — a field that could change how we understand antibiotic resistance.

In a biofilm “community,” bacteria can do things that individual bacterial cells cannot — for example, forming barriers that protect inner bacterial cells from interventions like antibiotics. As a result, bacterial infections that become biofilms can be difficult, if not impossible, to treat with antibiotics. Not all biofilms are dangerous though, Squyres clarified: biofilms — and their expanded range of abilities beyond single cells — can assist with beneficial natural processes like carbon capture and agricultural growth.

The difficulty is how little is understood about how biofilms function. In order for scientists to affect a biofilm — whether for the treatment of an infection or to improve soil quality — a lot more information is needed about the roles individual cells play in these communities.

One ongoing mystery, for example, concerns the individual cells that sacrifice themselves, contributing to the collective’s defenses. Why do they behave this way, how do they know they need to, what signals do they receive, and how are the individual cells communicating with each other? Earlier work provided some answers during the earliest stages of biofilm development, but as the biofilms get bigger the picture gets murky.

Until recently, the inability to get a closer look at the process prevented scientists from learning more. “Biofilm formation is fast compared to other developmental systems,” Squyres said. “If you want to understand how you get from single cell to biofilm and back again, it helps to be able to watch the whole thing… My contribution has been to extend the time that we can watch to see the whole thing.”

Squyres reintroduced a decades-old technique to observe biofilm development at high resolution and in real time. Squyres used her background in math and computer science, as well as microscopy, to write code to capture real-time data of hundreds of thousands of cells, across 4 axes of information — time, horizontal area, vertical area. But storing the data is another hurdle.

As one of five 2025 awardees of the L’Oréal USA For Women in Science Program, Squyres will be able to expand her capture of data showing how biofilms function. “I’ve been dreaming about this experiment since I got to Caltech in 2021 with a suitcase and a dream,” Squyres laughed, “and now I have the funding to do it.”

When she’s not in the lab, Squyres can often be found in the library. “If you look back in history, those people were just as smart as we are,” she said. “The difference between us and them is that we know more. The power of what we have learned in the sciences has completely transformed our understanding of the world. We’re not smarter now; we just know more now.”

Being a scientist is like being in a dark basement with a flickering candle, Squyres explains. “You’re looking for a sculpture that you has only ever been vaguely described. So you don’t know exactly what you’re looking for and you’re surrounded by, by statues.” Fortunately, it’s a space shared by others – scientists of the past and present, too. Contrary to Squyres’ childhood conception about the life of a scientist, she now knows that collaboration is core to the work. “The experience of talking to somebody and realizing that you have seen two different angles on the same thing is one of the great joys,” she said.

With the ever expanding wealth of scientific knowledge comes infinite new questions. For Squyres, the new methods of studying biofilms have underlined just how pressing the study of these biological communities is. “There are a lot of existentially challenging problems in the sciences now,” said Squyres. “The one that’s closest to my work is the increase in antibiotic resistance. It’s already hard to treat biofilms with the antibiotics that we have now, but as we continue to use them, resistance develops.”

Squyres believes investing time and resources to antibiotic research is vital for the survival of humanity, but often risky for private companies. “We need somebody to work on this,” Squyres said, “and that’s where scientists like me come in.” Squyres wants to spend her life making a contribution to a hard problem for the good of society, and satisfy her own curiosity about the natural world. Building on the work of others “you really feel the sense that you are part of this progression or chain of human knowledge,” she said. Like an individual cell in a biofilm, she has her own role to play. “As academic scientists, our responsibility is to be stewards of public resources to do research for public good.”