A Scientific Journey of Adaptation

From switching fields to studying microorganisms that live in extreme conditions to setting up a lab during the pandemic, a Jefferson researcher shares her story of persistence and creating opportunities for underrepresented scientists.

“When I tell people that my research is funded by NASA, that always catches their interest,” says Manuela Tripepi, PhD. “The organism I study is able to adapt to extreme conditions, some of which are found in the nearest extraterrestrial environments likely to harbor life.”

The organism Dr. Tripepi, assistant professor of biology in Jefferson’s College of Life Sciences, is talking about is haloferax volcanii, a type of microorganism called haloarchaea that is able to adapt to places most life can’t survive in. It was first isolated from the Dead Sea, one of the saltiest bodies of water on Earth.

“If you’ve flown out west or visited places like Death Valley, you might see these big pinkish-orange patches – that hue comes from millions of haloarchaea living in salt flats,” she explains.

Orange and pink salt flats as seen from above, with millions of haloarchaea living in them.

For researchers like Dr. Tripepi, haloarchaea help identify potential adaptation strategies to extraterrestrial environments, and can give us clues about organisms that could exist beyond Earth. With climate change increasing the salinity of bodies of water, these organisms are continuing to adapt, and may help us understand our planet’s changing ecosystems.

Much like the organism she studies, Dr. Tripepi has had to adapt to challenging environments, though perhaps not quite as harsh. She navigated her way as a young immigrant scientist in the US, after a summer trip to Philadelphia from her hometown in Italy turned into a second PhD; she found a way to continue research when the pandemic forced her lab to shutter; and she shared, and continues to share, her story of being a member of the LGBTQ+ community with her students, in the hopes of increasing visibility of underrepresented minorities in science and academia.

The World of Science, in a Small Town

Dr. Tripepi was born and raised in Cosenza, a small town in southern Italy. Her first exposure to the world of science was through her parents. Her father is a zoologist and ecologist at the University of Calabria, and her mother, now retired, worked for the city, assessing water pollution from nearby industries. “From a young age, I saw the life of a scientist,” she remembers. “I travelled to conferences with my dad and from his passion for the natural sciences, I was drawn to biology.”

She attended the University of Calabria for her undergraduate degree, and this is where she found that her interests diverged from her dad’s. Unlike his study of animals, she found herself fascinated by plants and their molecular workings. In 2005, she began a PhD at the same university in plant biology, studying how olive plants respond to stress like drought.

“When an animal encounters a stressful stimulus they can move away, but plants can’t just pick up and leave,” says Dr. Tripepi. “So they have developed molecular mechanisms to respond to a stressor like lack of hydration. For instance, they can produce proteins to strengthen their cells walls, to prevent drooping. It’s fascinating.”

At the beginning of her second year of her PhD, she decided to look into summer research internships in the US. Her father encouraged her, knowing that the extensive scale of research there would provide a good learning opportunity. She ended up at Villanova University in Pennsylvania. It was a summer that would change her life.

A Career-Shaping Opportunity

While at Villanova, Dr. Tripepi decided to shoot her shot – she was in the same vicinity as researchers she had admired from afar, reading about their work in scientific journals half way across the world. She wanted the opportunity to meet with them. She went on a spree of cold-emailing professors at different universities, not sure if she would get a response. One of those professors was Dr. Mecky Pohlschröder at the University of Pennsylvania. Dr. Tripepi’s thesis work on understanding salt tolerance of olive plants led her to Dr. Pohlschröder’s work on the micro-organism haloarchaea, which thrive in high salt concentrations. Dr. Pohlschröder, intrigued by this forthright and enthusiastic student from Italy, replied with an invitation to interview at her lab. Dr. Tripepi leapt at the opportunity.

“I’ll never forget that day. It was raining so hard, and I was completely lost,” recalls Dr. Tripepi. “My English was still not great, and I was asking for directions. Finally, I made it to Dr. Pohlschröder’s lab.”

“I remember she was completely drenched, but she didn’t let it faze her,” says. Dr. Pohlschröder. “Just from the first few minutes of talking to her, I could tell she was just really excited to do science. She reminded me of myself when I first moved to this country from Germany, eager to find an opportunity to do research.”

It’s one of the qualities that makes Manuela a good scientist – she’s got that self-confidence but she’s also not afraid to admit when she doesn’t know something.” Dr. Pohlschröder on Dr. Tripepi.

Dr. Tripepi brought a new perspective from plant biology to Dr. Pohlschröder’s world of microbiology, and the more the two talked, the more interesting research questions were formed. Though it was clear that Dr. Tripepi had a lot to learn about the overarching domain of archaea and the various classifications like haloarchaea, she was more than up to the challenge. Her passion was tangible, and Dr. Pohlschröder offered her a chance to spend the rest of the summer in her lab. As the summer came to an end, in another stroke of good fortune, Dr. Tripepi’s advisors at the University of Calabria agreed to let her finish the rest of her PhD in Dr. Pohlschröder’s lab. She would simultaneously complete her study of olive plants, and begin her foray into haloarchaea.

“I felt like I had won the lottery,” says Dr. Tripepi. “Dr. Pohlschröder took a chance on me and it single-handedly changed the course of my life.”

She now found herself as a young immigrant scientist in the US, her new home. She remembers fondly when her family came to visit when she moved into her first apartment. She didn’t have any furniture yet, so they had their first meal sitting on the floor around the coffee table before going shopping the next day. Even though her parents were sad that she would be far away, they were excited for her journey.

Dr. Tripepi observing a petri dish with haloarchaea colonies.

From Olive Trees to Haloarchaea

There were no olive trees in Philadelphia, so Dr. Tripepi bought some to be delivered from California. She grew them in the greenhouse on campus and was able to continue her investigations. Her doctoral work found that the olive plants produced proteins belonging to the family called dehydrin, and that the subtype and levels produced were different if the plant experienced lack of water vs. a mechanical stress like an animal grazing on its leaves.

After Dr. Tripepi completed her PhD, Dr. Pohlschröder said she could stay on as a postdoctoral researcher and finish the work she had started on haloarchaea. In a move that surprised many, Dr. Tripepi  decided to pursue a second PhD. “I had already learned so much from Mecky. She taught me how to be precise and detail-oriented, and that your experiment is only as good as your control. But I still felt like I had more to learn about microbiology.”

“It’s one of the qualities that makes Manuela a good scientist – she’s got that self-confidence but she’s also not afraid to admit when she doesn’t know something,” observes Dr. Pohlschröder. “She knew it would take a few more years to finish another PhD, but she used that time to grow as a scientist and make some big advancements to the field.”

Dr. Tripepi with Dr. Pohlschröder (left).
Celebrating Dr. Tripepi's graduation with her second PhD from the University of Pennsylvania.

Haloferax volcanii (H.volcanii) had long been thought as non-motile, or unable to move. While analyzing its genome Dr. Tripepi and Dr. Pohlschröder found sequences that were similar to ones that code for the flagella, a whip-like structure that allow various micro-organisms to move. Through a series of seminal publications, Dr. Tripepi was the first to show that H. volcanii is motile, contrary to dogmatic thought. She also described how the flagella of H.volcanii differed in structure and function from flagella found in other organisms like bacteria.

“Motility in H.volcanii is now a huge field, and there’s a lot of interest in how changing environmental conditions and nutrient availability can affect this organism’s movement. In fact I have students in the lab still building on Manuela’s foundational work,” says Dr. Pohlschröder. “She was instrumental in setting up the experimental system and getting it to work perfectly.”

In 2013, Dr. Tripepi graduated from the University of Pennsylvania, two PhDs in hand. Still, like many immigrant scientists, the worry of visa restrictions and the pressure to find a job that accepted non-US citizens was always hanging overhead. In fact, she was one month from her visa expiring and having to leave the country when she got her first teaching job.

Finding Research Beyond the Petri Dish

In graduate school, Dr. Tripepi was known for her dedication to mentorship and teaching. Outside of the lab, she was (and still is) an avid soccer player and would volunteer in soccer camps for kids. At graduate school, she was a favorite teaching assistant and she mentored high school and undergraduate students in the lab, often including them on papers. Through these interactions, she developed a passion for how best to make science engaging to students.

In 2017, she collaborated with Dr. Pohlschröder’s lab once again to use H.volcanii as a model to study DNA repair in a laboratory activity for high school students. She has also published a laboratory curriculum for undergraduates to study the central dogma of biology.

All these skills came in handy for Dr. Tripepi when she joined Jefferson in 2020. Just as she was getting ready to set up her lab, the pandemic hit and the country went into lockdown, forcing her to hit pause on her plans to continue studying stress responses in archaea and plants. Still, she wanted a way to offer undergraduates research experiences that were safe.

Dr. Tripepi setting a camera trap to observe wildlife at Jefferson's East Falls campus.

Drawing on her pedagogical experience and observations of her dad’s ecological research, she turned to the outdoors. She developed a COVID-friendly protocol to monitor wildlife on East Falls’ campus. Using trail cameras placed in different locations and operated remotely, students could collect data on which species are present; patterns in behavior; and how varying human presence through tamping down and lifting of COVID restrictions affects the animals’ presence.

“The students were so surprised to see the diversity of wildlife that we have right here – we have seen deer, foxes, raccoons, various birds, and of course, domestic cats and dogs,” says Dr. Tripepi. “They’ve been able to learn the scientific method by proposing a hypothesis, collecting and analyzing data, and presenting the results to the rest of the group, virtually of course.”

Grazing deer caught on a camera trap set by Dr. Tripepi and her students.

The students now have over a year’s worth of data that they’ve been able to share in poster sessions and thesis projects. They recently won a grant that will allow them to expand the project to observe birds with smart bird feeders.  Dr. Tripepi was also able to hone this teaching approach and just recently published on it, hoping it can be adapted at other college campuses with proximity to wildlife and offer undergraduates a unique research opportunity. Dr. Tripepi is also documenting the efforts on social media.

Sharing her Story to Increase Visibility

Perhaps the reason Dr. Tripepi has been able to pivot so skillfully in her scientific journey, is because she has had to do the same in her personal life. Her move to the US from Italy was fueled by her scientific pursuits, but a significant impetus was also to find acceptance as a member of the LGBTQ+ community.

Growing up, she knew that she was not attracted to boys like the other girls around her. The older she got, the more secure she felt in who she was. She first came out to her sister, who was supportive. “My mom had already figured things out by then, so she didn’t seem surprised when I told her. My dad was supportive, but he was very worried about how our community would treat me and that my life would be more difficult,” she remembers. “He approached it very scientifically, he did a lot of reading and tried to educate himself.”

Dr. Tripepi with her father at her PhD graduation from the University of Pennsylvania.

While her immediate family fully supported her, it took more time for her to open up to extended family. Her parents were also fiercely protective of her identity. “I never came out to my grandparents, who both passed away,” she says. “But I did visit once with my girlfriend at the time, now my wife. And it was just like in the movies, my grandmother kept asking me about my “roommate” Rachael. But I believe she knew.”

In some ways, even though living by herself in the US was hard, it gave Dr. Tripepi the freedom to live her life authentically; she worried less about what people would think or her family being antagonized. The same self-confidence that Dr. Pohlschröder noticed in Dr. Tripepi’s scientific endeavors was apparent in the openness and honesty with which she embraced her identity.

“Even though things were changing at the time, there were not many openly LGBTQ+ scientists in the academic space,” says Dr. Pohlschröder. “It was very impactful for students and the younger generation of scientists, to not only see Manuela accept herself, but accept them too.”

Every semester, I tell my story to my students. Visibility matters.” – Dr. Tripepi.

Disparities and barriers continue to persist for LGBTQ+ scientists. A survey conducted earlier this year of nearly 25,000 researchers across STEM showed that compared to their non-LGBTQ+ colleagues, LGBTQ+ scientists were more likely to experience harassment and career obstacles, with both of these negatively impacting physical and mental well-being. Many expressed experiencing insomnia and depression. Research has shown that visibility of more LGBTQ+ role models, like Dr. Tripepi, in science would make it easier for other LGBTQ+ students to join the field.

In 2015, when same-sex marriage was legalized in the US Dr. Tripepi was able to marry her partner. Her family came from Italy for the wedding and the ensuing celebrations; it was a day to remember and a step further step to equality and representation.

“I am open about my story with my colleagues. Every semester, I tell my story to my students,” says Dr. Tripepi. “Even though I am an underrepresented minority in science, I recognize the privilege I have compared to other communities. I want to be able to provide my students the same kind of opportunities given to me. Visibility matters.”

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