Bensasson uses yeast to unlock life鈥檚 greatest mysteries

Douda Bensasson
Douda Bensasson, an associate professor in UGA鈥檚 Department of Plant Biology, is researching yeast to uncover secrets about different species鈥 ability to survive in rapidly changing climates, as well as how those changes impact fungal pathogens. (Photo by Peter Frey)

What comes to mind when you think of yeast? To a baker, it might mean the ability to make their dough rise. A brewmaster might associate it with the fermentation of beer and wine. Many others may associate these types of fungus with one dreaded infection or another.

Yeast serves many functions. For the 华人第一情色社区鈥檚 Douda Bensasson, it鈥檚 all of these鈥攁nd more.

An associate professor in the 鈥檚 Department of Plant Biology, Bensasson uses yeast to unlock some of life鈥檚 greatest mysteries. Among the questions she seeks to answer is one concerning the fate of some of earth鈥檚 species. How will different species cope with the impacts of a warming climate? Will they adapt or go extinct?

鈥淪ome yeasts adapt well to different climates, while others don鈥檛,鈥 Bensasson explained. 鈥淚n our lab, we are using that as our testing ramp to try and figure out what the rules are about which species make it and which species don鈥檛, who is able to migrate and who cannot.鈥

In the lab, Bensasson and her team can finely control yeasts鈥 growing conditions, yielding illuminating results about a species鈥 ability to survive in a world where weather patterns are becoming more extreme and habitats are uprooted. The results could apply to other species that are difficult to study, such as endangered animals or plants, as well as other microscopic fungi.

Another area of rising concern is fungal disease in areas experiencing drastic climate change. To address these concerns, Bensasson has broadened her research into pathogens.

鈥淭his is a sweet spot for me,鈥 Bensasson said. 鈥淚 am well positioned to help in that area in terms of identifying some kind of warning system for new fungal diseases, for example, by using PCR tests to identify pathogenic yeast in wastewater, food or agriculture.鈥

鈥楳assive yeast envy鈥

These days, Bensasson works almost entirely with yeast. But that was not always the case.

She started her research on mountain grasshoppers, work that quickly posed several challenges. Although these creatures had once been widely researched, due to their large chromosomes that could be easily observed under a microscope, Bensasson found that they were very difficult to breed.

鈥淚t was like trying to breed panda bears,鈥 she said with a laugh. 鈥淚t was impossible to get them to survive and ultimately work with them.鈥

The grasshoppers were equally difficult to find in nature. Bensasson traveled to the Alps, one of their natural habitats, to collect samples for research, only to find that warming temperatures had driven them from areas in which they had been studied just 10 years prior.

Bensasson pressed on. Several years later, however, as a Fulbright Royal Society fellow at Harvard, she got the chance to work alongside scientists who were experimenting with yeast. Through these encounters, she admits to what she now calls 鈥渕assive yeast envy.鈥

鈥淚 was in a lab with people working on yeast, and they were just there鈥攖rillions of them, living happily among themselves,鈥 Bensasson said. 鈥淭hey are incredibly easy to work with, and we can control their growing conditions. We can control their climate with the push of a button. So, yes, they are much easier to work with than grasshoppers.鈥

A discovery decades in the making

Throughout her career, one of Bensasson鈥檚 most significant discoveries involved the yeast species Candida albicans, which is responsible for a potentially lethal bloodstream infection in humans. Despite the danger it poses, C. albicansis extremely common. In fact, according to Bensasson, more than 50% of the population will have C. albicans living on or within them at some point during their lives.

C. albicans is the biggest cause of hospital visits and death out of all the fungal infections,鈥 Bensasson said. 鈥淚t really does affect most people.鈥

It was previously thought that C. albicans could survive only within warm-blooded creatures, but Bensasson鈥檚 lab discovered that old oak trees could harbor the pathogen. Previous researchers had raised the possibility of these reservoirs going back decades, but their findings were dismissed as inadvertent human contamination of the trees.

Candida albicans and Candida auris are two pathogenic yeasts that cause candidiasis. C. auris has acquired multiple drug resistance. It's infection of the bloodstream, the central nervous system and other internal organs can end deadly.
One of Bensasson鈥檚 major research contributions has been the discovery that oak trees can harbor the potentially dangerous Candida albicans, a yeast species previously thought to only live within warm-blooded creatures. The discovery opened other avenues of study, like a search for new cures in the presence of C. albicans鈥 natural enemies.

Bensasson鈥檚 research was the first to prove conclusively that these trees do indeed harbor C. albicans, and although the risk of yeast infection from trees is effectively zero, it鈥檚 critical that scientists understand natural reservoirs of disease.

鈥淲hen we first found it on trees, my colleague Michelle Momany was like, 鈥極h my gosh, you鈥檝e got to prove that they really live there, because that鈥檚 going to shock everyone,鈥欌 Bensasson said.

The discovery that wild plant environments serve as reservoirs for common fungal infections like C. albicans has across the globe that corroborate these findings.

鈥淚t鈥檚 also exciting to find these natural reservoirs of the pathogens because they鈥檒l have natural enemies there,鈥 Bensasson said. 鈥淪o, it鈥檚 potentially a place where we could search for new cures. We could find and research the enemies of our enemies, so to speak.鈥

In recognition of this exceptional finding, Bensasson was honored with the UGA Creative Research Medal in April 2022. She credits her colleagues for pushing her throughout the nomination process, particularly John Burke, head of UGA鈥檚 Department of Plant Biology, and Michelle Momany, a fellow researcher in her department.

鈥淚t means a lot to be so appreciated by my colleagues that they kept insisting on nominating me,鈥 Bensasson said. 鈥淚 love my research, so this was a true honor.鈥

Diversifying the next generation of researchers

Bensasson has not only been recognized for her research but has also for her stalwart efforts to diversify the next generation of STEM researchers. For her, diversity is not merely an interest鈥攊t鈥檚 a prerequisite to running any laboratory. Growing up in the United Kingdom as the daughter of Greek immigrants and learning English as a second language, she knew early on what it鈥檚 like to feel different. She has taken these experiences with her throughout life.

鈥淚鈥檝e definitely been in situations where I felt I didn鈥檛 belong,鈥 Bensasson said, 鈥渟o I just want to make other people feel they belong. If people can’t truly be themselves and be creative and flourish, then we aren鈥檛 truly tapping into the best science.鈥

Bensasson has worked to identify tactics that can be used to stimulate an inclusive laboratory environment, including racial and gender equity. An additional problem in STEM, she said, is that undergraduate students with research experience are sometimes favored over those without it, disadvantaging those who come from marginalized backgrounds.

鈥淎nother one of the barriers I鈥檝e seen is students thinking by the time they get to grad school, they should have all this experience in computing,鈥 Bensasson said. 鈥淭hey think they鈥檝e missed out鈥攂ut they haven鈥檛. That鈥檚 what grad school is all about: picking up new experiences.鈥

In order to overcome these barriers, Bensasson does not require undergraduate researchers to have prior research experience in order to join her lab, or graduate students to have computing experience. She also champions paying student researchers so that students of all economic backgrounds can participate.

As a testament to her convictions, Bensasson was recently awarded the from the Howard Hughes Medical Institute, alongside UGA graduate student Jacqueline Pe帽a. This award is meant to ensure that students from historically marginalized groups are prepared to assume leadership roles in science and scientific education, and to foster the development of a healthier, more inclusive academic ecosystem within the sciences.

鈥淚 have learned so much through this award about supporting students that face microaggressions, systemic biases and just being a better mentor generally,鈥 Bensasson said. 鈥淚t鈥檚 really taught me a lot of things I strive to implement in my own lab and life.鈥