Tag Archive for Cohan

Student Researchers Discover Potential “Plastic-Eating” Bacteria on Campus

by Olivia Drake • September 29, 2021

Chloe De Palo ’22 explains how potential plastic-degrading bacteria were collected from a soil sample at Long Lane Farm.

A team of researchers at Wesleyan has discovered new strains of bacteria—located on the University’s campus—that may have the ability to break down microplastics and aid in the world’s ongoing plastic waste crisis.

Microplastics, which measure less than .20 of an inch, enter the ecosystem— and our bodies— largely through the abrasion of larger plastic pieces dumped into the environment. According to a study published in the Journal of Environmental Science and Technology, the average person consumes at least 50,000 particles of microplastic a year and inhales a similar quantity.

“Plastic is typically classified as a non-biodegradable substance. However, some bacteria have proven themselves to be capable of metabolizing plastics,” said Chloe De Palo ’22. “Ultimately, through our research and experiments, we hope to find an effective method of removing plastic pollutants from the environment.”

Fatai Olabemiwo

De Palo ’22, along with Rachel Hsu ’23; Claudia Kunney ’24; and biology PhD candidate Fatai Olabemiwo are members of the Cohan Laboratory in Microbiology, led by Fred Cohan, Huffington Foundation Professor in the College of the Environment, professor of biology. The team has spent almost two years working on a project titled “Isolating Potential Plastic Degraders from a Winogradsky Column.” They presented their most recent findings at Wesleyan’s Summer Research Poster Session.

On March 7, 2020 the research team gathered soil samples from Wesleyan’s Long Lane Farm. They placed samples of the agricultural soil, along with plastic strips, inside a modified Winogradsky column, a microbiological tool for culturing broad microbial diversity. The device—invented by Russian scientist Sergei Winogradsky in the 1880s—is still commonly used today to culture bacteria from natural soil and sediments.

Pictured is a Winogradsky column on day 1 (March 7, 2020) and day 496 (June 28, 2021)

“We modified this wonderful device to yield a range of plastic degrades by placing plastic strips at four different zones inside the column,” Olabemiwo explained. “Then we added a medium called Bushnell-Haas Broth, which contains all the requirements for the growth of the microbes except for carbon, to the modified device.”

Now that the columns are sealed, it’s time to wait—for 16 months.

“During this time, we expected the bacteria to ‘tickle’ the strips and eventually adhere to the strips,” Olabemiwo said.

The experiment worked surprisingly well. After 496 days in the soil-broth mixture, Cohan Lab members removed the plastic strips aseptically. Not only did they weigh less, proving that bacteria were effectively decomposing the plastic, but the strips also hosted a diverse community of bacteria from which the lab members isolated 146 strains.

While the majority of the bacteria cultures could be identified through the National Center for Biotechnological Information (NCBI) taxonomy browser, the researchers learned that 24 were discovered species but not characterized and classified, and 28 were novel, undiscovered species.

“We’ll actually be naming them, genomically sequencing them, and adding them to the NCBI taxonomy browser, ” Cohan said.

Now that each bacterium is isolated, the Cohan Lab is working this fall to confirm their potential plastic-degrading abilities by feeding them minute plastic discs in a petri dish. If confirmed, the “plastic-eaters” could help biotechnological companies create a product that could remove microplastics from the environment.

Rachel Hsu ’23, Chloe De Palo ’22, and Claudia Kunney ’24 are the undergraduate researchers working on the project.

Rachel Hsu, a biology and psychology double major, holds samples of the isolated bacteria in a petri dish.

Students’ Essays on Infectious Disease Prevention, COVID-19 Published Nationwide

by Olivia Drake • December 17, 2020

More than 25 students in Fred Cohan’s Global Change and Infectious Disease course have had op-eds published in media outlets nationwide. Cohan, professor of biology and Huffington Foundation Professor in the College of the Environment (pictured), assigns the op-ed writing as part of his course and offers students extra credit if they are able to get their work published.

As part of the BIO 173: Global Change and Infectious Disease course, Professor Fred Cohan assigns students to write an essay persuading others to prevent future and mitigate present infectious diseases. If students submit their essay to a news outlet—and it’s published—Cohan awards them with extra credit.

As a result of this assignment, more than 25 students have had their work published in newspapers across the United States. Many of these essays cite and applaud the University’s Keep Wes Safe campaign and its COVID-19 testing protocols.

Cohan, professor of biology and Huffington Foundation Professor in the College of the Environment (COE), began teaching the Global Change and Infectious Disease course in 2009, when the COE was established. “I wanted very much to contribute a course to what I saw as a real game-changer in Wesleyan’s interest in the environment. The course is about all the ways that human demands on the environment have brought us infectious diseases, over past millennia and in the present, and why our environmental disturbances will continue to bring us infections into the future.”

Over the years, Cohan learned that he can sustainably teach about 170 students every year without running out of interested students. This fall, he had 207. Although he didn’t change the overall structure of his course to accommodate COVID-19 topics, he did add material on the current pandemic to various sections of the course.

“I wouldn’t say that the population of the class increased tremendously as a result of COVID-19, but I think the enthusiasm of the students for the material has increased substantially,” he said.

To accommodate online learning, Cohan shaved off 15 minutes from his normal 80-minute lectures to allow for discussion sections, led by Cohan and teaching assistants. “While the lectures mostly dealt with biology, the discussions focused on how changes in behavior and policy can solve the infectious disease problems brought by human disturbance of the environment,” he said.

Based on student responses to an introspective exam question, Cohan learned that many students enjoyed a new hope that we could each contribute to fighting infectious disease. “They discovered that the solution to infectious disease is not entirely a waiting game for the right technologies to come along,” he said. “Many enjoyed learning about fighting infectious disease from a moral and social perspective. And especially, the students enjoyed learning about the ‘socialism of the microbe,’ how preventing and curing others’ infections will prevent others’ infections from becoming our own. The students enjoyed seeing how this idea can drive both domestic and international health policies.”

A sampling of the published student essays are below:

Alexander Giummo ’22 and Mike Dunderdale’s ’23 op-ed titled “A National Testing Proposal: Let’s Fight Back Against COVID-19” was published in the Journal Inquirer in Manchester, Conn.

They wrote: “With an expansive and increased testing plan for U.S. citizens, those who are COVID-positive could limit the number of contacts they have, and this would also help to enable more effective contact tracing. Testing could also allow for the return of some ‘normal’ events, such as small social gatherings, sports, and in-person class and work schedules.

“We propose a national testing strategy in line with the one that has kept Wesleyan students safe this year. The plan would require a strong push by the federal government to fund the initiative, but it is vital to successful containment of the virus.

“Twice a week, all people living in the U.S. should report to a local testing site staffed with professionals where the anterior nasal swab Polymerase Chain Reaction (PCR) test, used by Wesleyan and supported by the Broad Institute, would be implemented.”

Kalyani Mohan ’22 and Kalli Jackson ’22 penned an essay titled “Where Public Health Meets Politics: COVID-19 in the United States,” which was published in Wesleyan’s Arcadia Political Review.

They wrote: “While the U.S. would certainly benefit from a strengthened pandemic response team and structural changes to public health systems, that alone isn’t enough, as American society is immensely stratified, socially and culturally. The politicization of the COVID-19 pandemic shows that individualism, libertarianism and capitalism are deeply ingrained in American culture, to the extent that Americans often blind to the fact community welfare can be equivalent to personal welfare. Pandemics are multifaceted, and preventing them requires not just a cultural shift but an emotional one amongst the American people, one guided by empathy—towards other people, different communities and the planet. Politics should be a tool, not a weapon against its people.”

Sydnee Goyer ’21 and Marcel Thompson’s ’22 essay “This Flu Season Will Be Decisive in the Fight Against COVID-19” also was published in Arcadia Political Review.

“With winter approaching all around the Northern Hemisphere, people are preparing for what has already been named a “twindemic,” meaning the joint threat of the coronavirus and the seasonal flu,” they wrote. “While it is known that seasonal vaccinations reduce the risk of getting the flu by up to 60% and also reduce the severity of the illness after the contamination, additional research has been conducted in order to know whether or not flu shots could reduce the risk of people getting COVID-19. In addition to the flu shot, it is essential that people remain vigilant in maintaining proper social distancing, washing your hands thoroughly, and continuing to wear masks in public spaces.”

by Olivia Drake • September 24, 2020

On Sept. 22, faculty, staff, and students gathered on Zoom for a “Talk It Out” that related to the Theater Department’s upcoming production of SLABBER. Directed and created by Katie Pearl, assistant professor of theater, SLABBER is an open-air, interactive, socially distanced performance that brings viewers directly into the research and experiments of a group of people who are trying to identify a mysterious condition, known only as “slabber.” The interdisciplinary conversation, titled “Dis/Ease: Contagion and Pandemics in Our World and Its Stories” was facilitated by Luna Mac-Williams ’22, pictured at top, center.

The SLABBER performance invites viewers to consider notions of social and physical contamination and asks whether it’s possible to come close to someone else across a great distance. During the “Talk It Out,” guest speakers Fred Cohan, Huffington Foundation Professor in the College of the Environment, professor of biology; and Anthony Hatch, associate professor of science in society, offered their insight on how pandemics and contagion play out in our world and in our stories. Participants discussed the topics of contagion and how concepts of “dirty/clean” are changing social constructs.

Cohan spoke about the idea of purification. “When biologists learned about the microbiome, we lost the idea that there was something pure about our bodies, and the more we can scrub ourselves of those nasty bacteria, the better our lives would be. And it turns out, now it’s the opposite,” he said. “How hard do you really want to scrub to make yourself pure? It would be a dangerous exercise, and nobody really knows how bad an idea that would be.”

Hatch, who worked as an HIV/AIDS educator in the 1990s and early 2000s, noted that scholars find repetitive themes with the emergence of new infectious epidemic and pandemic diseases. “It’s quite easy to vilify a particular group that you believe is responsible for what has happened. Now, we have the so-called ‘China virus,’ which is a racist ploy designed to take attention away from the lack of leadership and [terms of] providing testing, which should happen. We saw this in 1918. . . . This has happened with everything from AIDS to Zika, and now with the COVID-19 pandemic. . . . We’re asking, who’s bringing the infection, what’s the source of the infection, how do we prevent the infection?”

“There’s a word I want to drop into the conversation and that is stigma,” Pearl said. “I’m thinking back to that moment, in the beginning [of the pandemic], when you wouldn’t want to put a mask on because you wouldn’t want people to think you were sick. The stigma around dirtiness is so huge, it keeps us from putting on that external marker of protection, to protect you from other people, and that is what has taken us down. It’s the stigma.”

The discussion was sponsored by the Creative Campus Initiative, Office of Academic Affairs, and the Theater Department. Theater Department “Talk It Outs” occur at least once a semester, and serve as a way to invite the larger Wesleyan community into an interdisciplinary, open conversation around the issues the productions are framing. SLABBER will be performed Oct. 16–18 on the Center for the Arts green, and will be open to 48 audience members each night.

Reserve your spot for a SLABBER performance here.

Cohan: Human Behavior Affects Virus Evolution

by Lauren Rubenstein • April 5, 2020

Frederick Cohan

Frederick Cohan, the Huffington Foundation Professor in the College of the Environment, professor of biology, is a microbial ecologist whose course “Global Change and Infectious Disease” examines how human disturbance of the environment contributes to infectious disease outbreaks. He also researches the origins of diversity among both bacteria and viruses.

In early February, as the novel coronavirus was beginning to spread, Cohan wrote an article in The Conversation, co-authored with PhD candidate Kathleen Sagarin and Kelly Mei ’20, titled, “A Clue to Stopping Coronavirus: Knowing How Viruses Adapt From Animals to Humans.”

Cohan also was interviewed recently by The Wesleyan Argus about the biology of the coronavirus.

You teach a course on Global Change and Infectious Disease, which looks at how human disturbance of the environment can contribute to infectious disease outbreaks like the one we’re now living through. Can you give us a brief introduction to the course?

I teach this course every year or two, and there are usually over 170 students enrolled. I’m also in the middle of writing a book based on the course content. We talk about five categories of environmental disturbance that humans are creating or have created in the past that bring new diseases to us or exacerbate existing ones. The categories are: demand for food (hunting and agriculture), demand for land (living at high density), demand for travel, demand for energy, and demand for health care (including antibiotics).

by Lauren Rubenstein • March 2, 2020

Wesleyan in the News
1. The Open Mind: “Democratizing the Jury”

Associate Professor of Government Sonali Chakravarti is interviewed in connection with her new book, Radical Enfranchisement in the Jury Room and Public Life, in which she offers a “full-throated defense of juries as a democratic institution.” “I am very interested in how ordinary people engage with political institutions, and juries are the place where ordinary people have the most power,” she says. Chakravarti calls for more robust civic education, continuing into adulthood, in order to have a “more effective, modern jury system.”

2. Hartford Courant: “Sen. Murphy, Aiming to Expand Pell Grant Eligibility for Incarcerated Students, Hears from Inmates at York Correctional Institution”

Senator Chris Murphy, who is the co-sponsor of a bill to expand the federal Pell grant program for college students to include inmates, met with 11 inmates who have participated in educational programs at York Correctional Institution through the Wesleyan Center for Prison Education and other college-in-prison programs.“What’s important about the REAL Act is that college affordability should be accessible to all students regardless of where they are,” said CPE program manager Allie Cislo. “It’s one thing rhetorically to commit to reentry,” she said, but resources like educational programs “can make or break it for people.”

3. American Theatre: “Digging for New Roots”

This article on “climate change theatre” features Ocean Filibuster, a play by Assistant Professor of Theater Katie Pearl through her theater company, PearlDamour. Commenting on the play’s premise, in which a new Senate bill proposes sentencing the world’s oceans to death and the ocean stands to speak in its own defense, Pearl said, “We thought, well, what if the ocean finally got fed up with taking all of our crap, and started talking and didn’t stop until we actually shut up and listened?” American Theatre, a leading publication in the theater industry, writes: “Ocean Filibuster recalibrates the human experience by reminding us of the comparatively small scale and depth of our own existence.”

by Lauren Rubenstein • February 13, 2020

Wesleyan in the News

1. Hartford Courant: “Jeanine Basinger, the ‘Professor of Hollywood,’ Is Wesleyan University’s Homegrown Screen Legend”

Corwin-Fuller Professor of Film Studies, Emerita Jeanine Basinger, whom this article notes has been dubbed “the professor of Hollywood” and “an iconic figure in American cinema, one of the most beloved and respected film history professors in the history of film studies” by The Hollywood Reporter, is interviewed on the occasion of her 60th year at Wesleyan, and the 50th since she created its film program. She talks about her next book on American film comedy, shares some of her favorite things, and muses on which actress would play her in a movie of her life.

2. Los Angeles Review of Books: “‘We Need More Vigorous Debate’: A Conversation with Michael S. Roth”

Daniel Steinmetz-Jenkins, managing editor of Modern Intellectual History, interviews President Michael Roth in connection with his latest book, Safe Enough Spaces: A Pragmatist’s Approach to Inclusion, Free Speech, and Political Correctness on College Campuses. Roth discusses his career path from intellectual historian to university administrator and professor, and offers his unique perspective on debates surrounding freedom of speech and political correctness.

3. Los Angeles Times: “Kirk Douglas Dead at 103; ‘Spartacus’ Star Helped End Hollywood Blacklist”

Jeanine Basinger, the Corwin-Fuller Professor of Film Studies, Emerita, comments on Kirk Douglas’s legacy following the film icon’s death at 103. Recalling when she first saw him on-screen in the 1940s, she said, “He wasn’t a traditional leading man, really, in looks, and yet he had an unmistakable charisma and power on screen—not just the glamour of the movie star, though he did have that, but real acting chops. So you knew he was going to be a star.” She added, “He was a very modern American antihero type, but he could also play anything, really.”

by Lauren Rubenstein • February 4, 2020

Fred Cohan

Wesleyan faculty frequently publish articles based on their scholarship in The Conversation US, a nonprofit news organization with the tagline “Academic rigor, journalistic flair.” In this article, Fred Cohan, professor of biology, Huffington Foundation Professor in the College of the Environment, PhD student Kathleen Sagarin, and Kelly Mei ’20 explain how viruses like coronavirus—and several others over history—spread from animals to humans, what determines the size of the outbreak, and how behavioral modifications and technology can stop the spread.

A clue to stopping coronavirus: Knowing how viruses adapt from animals to humans

As the novel coronavirus death toll mounts, it is natural to worry. How far will this virus travel through humanity, and could another such virus arise seemingly from nowhere?

As microbial ecologists who study the origins of new microbial species, we would like to give some perspective.

As a result of continuing deforestation, “bushmeat” hunting of wild animals and caring for our domestic animals, the novel coronavirus will certainly not be the last deadly virus from wild animals to infect humans. Indeed, wild species of bats and primates abound in viruses closely related to SARS and HIV, respectively. When humans interact with wild animal species, pathogens that are resident in those animals can spill over to humans, sometimes with deadly effects.

by Lauren Rubenstein • December 2, 2019

In this recurring feature in The Wesleyan Connection, we highlight some of the latest news stories about Wesleyan and our alumni.

Wesleyan in the News

CNN: “What the ‘Woke Student’ and the ‘Welfare Queen’ Have in Common”

“Every age seems to need a bogeyman, some negative image against which good people measure themselves,” writes President Michael Roth ’78 in this op-ed. Roth compares today’s bogeyman, the “woke” college student, with those of past eras—the “welfare queen” and “dirty hippie”—and seeks to build understanding and dispel negative misperceptions of activist college students. “The images of the welfare queen and of the woke student are convenient because they provide excuses to not engage with difference, placing certain types of people beyond the pale,” he writes. “These scapegoats are meant to inspire solidarity in a group by providing an object for its hostility (or derision), and educators and civic leaders should not play along.”

2. Los Angeles Times: “Opinion: Our Food Is Tainted with E. Coli, Yet the FDA Is Rolling Back Safety Rules”

As yet another food-borne E. coli outbreak sickens Americans, Fred Cohan, the Huffington Foundation Professor in the College of the Environment and professor of biology, and Isaac Klimasmith ’20, argue in this op-ed that more can and should be done to prevent dangerous contaminations of our food supply. The Food and Drug Administration (FDA) has rolled back rules that “would have required monitoring and treating irrigation water for E. coli,” a major cause of these outbreaks. “We should not be surprised that a regulation-averse administration would disregard the science of food safety, but it is concerning that consumers have become complacent about yearly outbreaks of E. coli contamination and largely silent about the rollback of food safety regulations,” they write.

3. The Washington Post: “What Happens When College Students Discuss Lab Work in Spanish, Philosophy in Chinese or Opera in Italian?”

Stephen Angle, director of the Fries Center for Global Studies, professor of philosophy, and the Mansfield Professor of East Asian Studies, is interviewed about Wesleyan’s efforts to promote language study, including the new Cultures and Languages Across the Curriculum (CLAC) initiative, through which students can study a range of disciplines in other languages. For example, Angle teaches a Mandarin-language section of Classical Chinese Philosophy, a course historically taught in English. Read more about CLAC and Wesleyan’s language instruction here.

by Lauren Rubenstein • December 10, 2018

In this recurring feature in The Wesleyan Connection, we highlight some of the latest news stories about Wesleyan and our alumni.

Recent Wesleyan News

1. Los Angeles Times: “As the World Warms, Deadly and Disfiguring Tropical Diseases Are Inching Their Way Toward the U.S.”

In this op-ed, Professor of Biology Frederick Cohan and Isaac Klimasmith ’20, both in the College of the Environment, write that infectious disease is a growing threat, resulting from climate change, that humans may find hard to ignore. Cohan is also professor, environmental studies and professor, integrative sciences.

2. Hartford Courant: “Trump’s Immoral Response to Climate Report”

Gary Yohe, the Huffington Foundation Professor of Economics and Environmental Studies, writes in this op-ed that it is “irresponsible” and “immoral” to ignore the findings of a major new report on climate change. Delaying action to mitigate and adapt to climate change will be increasingly damaging and expensive, he writes. Yohe is also professor of economics and professor, environmental studies, and was a reviewer on the new National Climate Assessment. He also recently co-authored an op-ed in HuffPost titled “People Are Already Dying by the Thousands Because We Ignored Earlier Climate Change Warnings.”

3. National Geographic: “Both of NASA’s Voyager Spacecraft Are Now Interstellar. Where to Next?”

With both of NASA’s twin Voyager spacecraft now having crossed the threshold into interstellar space, Seth Redfield, associate professor and chair of astronomy, comments on what the spacecraft are likely to encounter on their journey. Redfield is also associate professor, integrative sciences, and co-coordinator of Planetary Science.

4. Inside Higher Ed: “Ordinary Education in Extraordinary Times”

President Michael Roth writes in this op-ed that in uncommon times, “traditional educational practices of valuing learning from people different from ourselves have never been more important.”

Recent Alumni News

The Takeaway; WNYC Studios: “Politics with Amy Walter: Pentagon’s First-Ever Audit Exposes Massive Accounting Fraud”

David Lindorff ’71, the investigative journalist who wrote an exclusive on the topic for The Nation, joins Walter’s guests—including Staff Sergeant Patricia King, Ambassador Eric Edelman, and Dr. Isaiah Wilson III, a retired Army colonel and senior lecturer with Yale University’s Jackson Institute for Global Affairs—to discuss military spending and its alignment with the military’s strategic goals.

by Olivia Drake • June 19, 2017

Nicole DelGaudio ’18 samples the rhizosphere of a juniper tree.

This spring, a research team from Wesleyan traveled to Death Valley National Park to explore the ways bacteria diversifies in extreme environments.

Death Valley, located about 130 miles west of Las Vegas, is a below-sea-level basin known for being the hottest place on earth and driest place in North America. The average rainfall is less than 2 inches, annually.

“National parks are ideal for research, in general, because the land is protected indefinitely from commercial development,” said team leader Fred Cohan, professor of biology, professor of environmental studies. “Death Valley is a nice model system for exobiology because of its extreme habitat.”

Cohan, along with graduate student Jerry Lee, Bella Wiener ’19 and Nicole DelGaudio ’18, traveled to California May 29 through June 4. During this time, the researchers trekked through miles of parched — and often prickly — landscapes seeking to sample root soil, or rhizosphere, from various plant species, each over a wide range of elevations that differ notably in their temperatures.

by Lauren Rubenstein • April 25, 2017

Professor Laura Grabel, pictured sixth from left, attended the March for Science in New Haven, Conn.

Numerous Wesleyan faculty and students in the sciences attended the March for Science in different parts of the state and country on Earth Day, April 22.

Laura Grabel, the Lauren B. Dachs Professor of Science and Society, professor of biology, professor of environmental studies, professor of feminist, gender and sexuality studies, spoke at the New Haven march.

“I decided to march because science is being seriously threatened by the Trump administration,” she explained. “Trump has not filled almost all of the science positions, has no science advisor, and is using little evidence-based thinking in his decision making. Some of his appointments are puzzling and scary. From my perspective as a stem cell scientist, appointing Tom Price, who has consistently opposed embryonic stem cell research, as head of Health and Human Services presents a real danger to the future of this work just as therapies are entering clinical trials.”

by Frederic Wills '19 • February 20, 2017

Fred Cohan

Frederick Cohan, professor of biology, professor of environmental studies, has recently been elected to the Connecticut Academy of Science and Engineering (CASE). Set to be inducted during the 42nd Annual Meeting and Dinner on May 22, 2017, Cohan will join 23 others as “Connecticut’s leading experts in science, technology, and engineering,” and the academy’s newest members during their ceremony at the University of Connecticut.

In line with CASE’s mission to honor those “on the basis of scientific and engineering distinction, achieved through significant contributions in theory or application,” Cohan’s work has led to the “development of a comprehensive new theory for the origin, maintenance, and evolutionary dynamics of bacterial species diversity that integrates ecological and genetic criteria; and to the initiation and co-development of associated software tools, which allow microbiologists to identify distinct bacterial species from DNA sequence data.”

Cohan is a graduate of Stanford University, where he earned a bachelor’s degree in biological sciences in 1975. He went on to earn his PhD in organismic and evolutionary biology from Harvard University in 1982. His professional work takes him across the biological and environmental world, including, but not limited to topics such as microbial ecology, evolutionary theory, origins of bacterial diversity, molecular systematics and gene cluster analysis, horizontal genetic transfer and bacterial transformation.