Tag Archive for graduate students

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

Chloe De Palo '22

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

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.

project

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, Kunney, Chloe De Palo '22

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

bacteria

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

Students Gather to Honor Atlanta Victims, Combat Anti-Asian Violence

vigil

Students organized a vigil on March 30 to reflect on a recent attack against Asians and Asian Americans. (Photo by Nathaniel Pugh ’21)

On March 30, more than 150 students gathered outside Usdan University Center for a community vigil to mourn the victims of the March 16 Atlanta spa shootings and to create a safe space for Asian and Asian-American students to discuss the rise of anti-Asian violence and be heard by the community.

The vigil was organized by Emily Chen ’23, Kevin Le ’22, and graduate student Emily Moon, in conjunction with members of the Asian American Student Collective.

Students read poems, played music, and shared their reflections during the event. Towards the end, the organizers gave anyone moved to speak the opportunity to do so.

Tan ’20 Honored by Geological Society of America for Poster Presentation

GSAOn Nov. 23, the Geological Society of America’s (GSA) Geobiology and Geomicrobiology Division awarded earth and environmental sciences graduate student Yu Kai Tan ’20 with a student presentation award.

Tan presented his poster, “Freshwater Mussels in North America: Museum Collections and Pre-Industrial Biogeography,” on Oct. 29 during the GSA’s annual (virtual) meeting. Andy (Dick Yee) Tan ’21 collaborated with Tan ’20 on the poster. Their advisors are Ann Burke, professor of biology, and Ellen Thomas, Harold T. Stearns Professor of Integrative Sciences, Smith Curator of Paleontology of the Joe Webb Peoples Museum of Natural History, and University Professor in the College of Integrative Sciences.

Judges commended Tan’s poster for being “beautifully organized” and having a “terrific use of time and space.” They also noted that “the digitalization and processing of these collections is incredibly important to maintaining them and making them accessible for future research,” and the work “plays a vital role in understanding past and present biodiversity.”

poster

(click to enlarge)

7 Wesleyan Faculty, Alumni, Graduate Student Make Presentations at SEM Annual Meeting

semFour faculty, two alumni, and one graduate student participated in the virtual Society for Ethnomusicology Annual Meeting held Oct. 22–31.

As part of a panel addressing contemporary musical issues in Iran, Bridgid Bergin MA ’17 spoke about the Iranian Female Composers Association (IFCA), which was established in 2017 by three female-identifying Iranian composers: Anahita Abbasi, Niloufar Nourbakhsh, and Aida Shirazi. IFCA supports Iranian female-identifying composers by encouraging organizers and ensembles in Iran and beyond to commission and engage these composers in collaborations, while also discovering and mentoring young female composers who are fighting against all odds to become contemporary classical composers in 21st-century Iran. In 2018 the International Contemporary Ensemble (ICE) became an organizational partner in reinforcing IFCA’s platform as well as advocating for its members. Bergin presented three composer portrait videos and explored IFCA’s “her-story”—its founding members and an analysis of the intersections of gender, music, politics, and identity.

Eric Charry, professor of music, spoke about “An Ethnography of the Five Spot Café,” as part of a panel on rethinking jazz canons. Drawing on cultural geography, Charry examined from multiple perspectives the Five Spot Café (on the Bowery, 1956–62), one of the most important venues in jazz history: as an object in the Lower East Side and in downtown New York City jazz club landscapes; as a place imbued with sociocultural meaning; as a phenomenological space with a unique feel; and as a flashpoint in a historically dynamic scene. Moving beyond reports by American and European journalists, over a half-dozen live LP recordings, and published interviews with musicians, Charry focused on photographs taken inside the club. In this talk, Charry investigated race, gender, age, and especially modes of participation in jazz performance, and explored how an expanded view of ethnographic analysis of the inner workings of a historic venue has much to offer the history of jazz.

Students, Alumni to Make Presentations at Geological Society of America Meeting

Wesleyan students, graduate students, and recent alumni will present research posters during the annual Geological Society of America meeting Oct. 26–30. The virtual event will allow for a five-minute presentation followed by a five-minute period to answer questions.

poster

Earth and environmental sciences graduate student Yu Kai Tan ’20 and Andy (Dick Yee) Tan ’21 will present their poster, titled “Freshwater Mussels in North America: Museum Collections and Pre-Industrial Biogeography,” at 5:15 p.m. Oct. 29. Their advisors are Ann Burke, professor of biology, and Ellen Thomas, Harold T. Stearns Professor of Integrative Sciences, Smith Curator of Paleontology of the Joe Webb Peoples Museum of Natural History, and University Professor in the College of Integrative Sciences. Listen to the presentation in advance online here.

PhD Candidate Drum Discusses Biology Research during Graduate Speaker Series

Drum

Zachary Drum, a PhD candidate in biology, delivered the first 2020–21 Graduate Speaker Series talk on Oct. 2 through Zoom. Drum’s advisor is Joseph Coolon, assistant professor of biology. The Coolon Lab uses genetic and genomic tools to better understand how insects evolve to form a resistance to pesticides, damaging $10 billion in crops annually.

Zachary Drum, a PhD candidate in biology, delivered the first 2020-21 Graduate Speaker Series talk on Oct. 2 through Zoom. Titled "The Forbidden Fruit: How Drosophila sechellia came to Love Morinda citrifolia," Drum's research explores how a fruit fly species in Africa is able to eat a poisonous fruit that flies in the the rest of the world would find toxic.

Titled “The Forbidden Fruit: How Drosophila sechellia came to Love Morinda citrifolia,” Drum’s research explores how a fruit fly species in Seychelles is able to eat a poisonous fruit (noni) that flies in the rest of the world would find toxic. Ripe noni fruit contains the fatty acid volatiles octanoic acid and hexanoic acid, which are poisonous to other Drosophila species. “The host fruit has these chemicals that they [sechellia] like, and other flies don’t. They’re attracted and resistant to the fatty acid volatiles in the noni fruit,” Drum explained. “So we’re trying to build this puzzle. How does it resist these volatiles?” (Slide show photo by Charlotte Freeland)

drum

Drum explained the two types of Drosophila sensory organs used for smelling, based on past research.

Graduate Speaker Series events are open to the entire Wesleyan community.

Graduate Speaker Series events are open to the entire Wesleyan community.

Music Graduate Students Share Recent Projects

On Sept. 23, two students from the Music Department kicked off the 2020–21 Wesleyan Music Graduate Series, which is being hosted on YouTube this semester. Hosted by Wesleyan’s Music graduate students, this series showcases the performance, compositional, and research capabilities of Wesleyan graduate music students, alumni, and other Wesleyan affiliates. Panels will be streamed in six weekly installments on Wednesdays at 8 p.m. during September and October 2020.

Wheeler

Stuart Wheeler, a second-year MA student, presented a talk and performance of his composition “Mr. Bernard Shaw from On Vivisection.” The song, which can be performed by 1–13 singers, is based on a poem Wheeler wrote using source text from On Vivisection. The content focuses on Shaw’s political opposition to the practice of vivisection in the late 19th and early 20th centuries.

Wheeler's construction of the text is drawn heavily from the composer, performance artist, and poet Jackson Mac Low.  "There's specific methods of selection and rearrangement of words in the text, and these methods are both nonintentional and completely pre-determined," Wheeler said. "I'm making no intentional decisions on the granular level, I'm simply developing my own system for selecting and rearranging words from the source text."

Wheeler’s construction of the text is drawn heavily from the composer, performance artist, and poet Jackson Mac Low. “There are specific methods of selection and rearrangement of words in the text, and these methods are both nonintentional and completely predetermined,” Wheeler said. “I’m making no intentional decisions on the granular level, I’m simply developing my own system for selecting and rearranging words from the source text.” Wheeler also explained that his piece is built around a single chord that forms the harmonic architecture for the piece.

Bianca

Bianca Iannitti MA ’19, a PhD candidate in ethnomusicology, presented an an autoethnographic case study of the 2018 song Italiana by Fedez and J-Ax. Iannitti, who is fluent in Italian, recalled overhearing the song during a trip to Italy in 2018. “Italiana became an immediate success and is considered Italy’s top summer hit of 2018,” she said. “It was an integral part of my local surroundings. I would hear it in passing on the radio, in retail stores, local bars, or even watching MTV with my cousins.”

video

Italiana’s chorus serves as a double entendre, to highlight the tourism, and popularity, and beauty of the Italian summer, while also revealing the cracks within this often romanticized portrayal of the country,” Iannitti said. “Although there are references to the summer weather, the Italian beachside, and the beautiful people, there also lies this double meaning, or added layer, which serves as a political critique against the country’s immigration policy as well as the treatment toward undocumented citizens.”

pizza

Iannitti pointed out several pop cultural references and cultural stereotypes in the song and video, including the use of hand gestures, the love of pizza and spaghetti, and a laid-back mindset. “The song’s Italian music style, lyrical content, and music video ultimately exemplifies the complexity of the Italian culture and its identity on a local, national, and international scale,” she said. (Image: Italiana by Fedez and J-Ax.)

Graduate Student McNeill Speaks on the Social, Cultural Aspects of the Black New Orleans Brass Band

graduate student speaker

As part of Wesleyan’s Graduate Speaker Series, Marvin McNeill, a PhD candidate in ethnomusicology, spoke about “Structures of Feeling and the Significance of Affectivity in the Social and Cultural Survivals of the Black New Orleans Brass Band,” on Feb. 7 in Exley Science Center.

McNeil explained how the institution of the Black New Orleans brass band represents a genealogic continuum that extends back to the arrival of the first enslaved Africans to the Louisiana Territory. "This continuum connects a violent past, marked by physical abuse of black bodies in the form of institutionalized slavery, to a violent present confounded by systemic poverty, social injustice, and police brutality," he said. In spite of extreme oppression, the brass band community continues to enrich and enliven both local communities through their iconic musical offerings.

McNeill explained how the institution of the Black New Orleans brass band represents a genealogic continuum that extends back to the arrival of the first enslaved Africans to the Louisiana Territory. “This continuum connects a violent past, marked by physical abuse of black bodies in the form of institutionalized slavery, to a violent present confounded by systemic poverty, social injustice, and police brutality,” he said. “In spite of extreme oppression, the brass band community continues to enrich and enliven both local communities through their iconic musical offerings.”

Cohan in The Conversation: A Clue to Stopping Coronavirus

Fred Cohan

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.

Karimi Shares Enzyme Research during Graduate Speaker Series

graduate student

Neuroscience and biology BA/MA graduate student Helen Karimi presented a Graduate Speaker Series talk on Nov. 1.

On Nov. 1, neuroscience and biology BA/MA graduate student Helen Karimi presented a Graduate Speaker Series talk titled “All good things come in pairs: Uncovering the activity of BcnI through co-localization microscopy.”

Karimi’s talk focused on restriction endonucleases (REases), a large family of enzymes that make sequence-specific cuts in DNA. As her abstract details, type IIP REases usually cleave sequences as homodimers. However, BcnI, an enzyme belonging to this subtype, acts in a different way. Karimi’s work aims to observe the fine details of BcnI’s cleavage mechanism by using Total Internal Reflection Fluorescence (TIRF) microscopy, an imaging technique in which only molecules within a few hundred nanometers of a glass surface are illuminated.

Paper on Bacteria Adhesion Named “Editor’s Pick” by Journal of Biological Chemistry

Rich Olson

Rich Olson

Katherine Kaus PhD '18

Katherine Kaus

A paper written by Associate Professor of Molecular Biology and Biochemistry Rich Olson and his former students was designated as an “Editor’s Pick” by the Journal of Biological Chemistry. Only 2% of the approximately 6,600 papers published each year in the journal receive this designation.

Titled “The 1.9 Å crystal structure of the extracellular matrix protein Bap1 from Vibrio cholerae provides insights into bacterial biofilm adhesion,” the paper, published on Oct. 4, explores how bacteria “glues” itself to surfaces in the environment. The co-authors include Alison Biester ’19, Ethan Chupp ’18, Jianyi Lu ’17, Charlie Visudharomn ’17 and Katherine Kaus PhD ’18. Kaus, who is first author on the paper, is featured in a special profile on the JBC website.

Bacteria commonly form structures called biofilms, which are communities of living cells encapsulated by a three-dimensional matrix of secreted proteins, nucleic acids, and carbohydrates. Biofilms are a defense mechanism against environmental challenges and play a role in many pathogenic diseases.

Wesleyan in the News

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

Wesleyan in the News

1. The Nation: “Edward Snowden Deserves to Be Tried by a Jury of His Peers, Just Like Everyone Else”

In this op-ed, Associate Professor of Government Sonali Chakravarti argues against the Justice Department’s decision to deny Edward Snowden’s request for a jury trial. She contends that in Snowden’s case, in which he is accused of leaking classified information from the National Security Administration in 2013, a jury trial “is not only a viable alternative to a hearing before a judge; rather, given the nature of the charges—where the defendant has supposedly acted to protect the people from the very state that would charge him with a crime—jury deliberation is the proper forum for discussion of appropriate punishment and is the bulwark against the potential misconduct of the state.”

2. Transitions Online: “Stuck in the Middle”

Peter Rutland, the Colin and Nancy Campbell Professor in Global Issues and Democratic Thought, professor of government, and Dmytro Babachanakh ’20 explore the history of U.S. involvement in Ukraine, and call upon U.S. leaders of both parties to stop “treating lesser powers as political instruments.”

3. Tulsa World: “Save the Little Grouse on the Prairie”

Alex Harold ’20 is the author of this op-ed that calls for the lesser prairie chicken to be placed on the endangered species list to get the protections it desperately needs, as over 90 percent of its habitat has been degraded or destroyed. While many haven’t heard of this bird, Harold explains that it is an “indicator species” that “reflect(s) the health of the entire prairie ecosystem.” Harold wrote the op-ed as an assignment in E&ES 399, Calderwood Seminar in Environmental Science Journalism, taught by Professor of Earth and Environmental Sciences Suzanne O’Connell, this semester. The Calderwood Seminars are offered in a variety of disciplines to teach students how to effectively communicate academic knowledge to the public. Read more here.