Three years ago at Hampton University, a historically Black university in Virginia, associate professor Indu Sharma and her students were excited to look at the deep-sea samples she had collected on a research cruise to the Atlantic slope. Are there any bacteria in there, they wondered? They released drops of seawater into petri dishes and allowed the culture to grow.

When they looked at it through a microscope, a curious sight emerged: tightly coiled, semi-circular cells that “didn’t look like a normal bacterial cell,” Sharma said. “They look like Cheetos!” her daughter later observed.

From left, Hampton University undergraduates Pa-Shun Hawkins and T’Kiyah Reeves are spending the summer at MBL with their biology professor, Indu Sharma, MBL’s 2021 E.E. Just Fellow. Credit: Dee Sullivan

Sharma returned to the MBL the next summer (she had attended the Microbial Diversity course in 2017). This time she was a student in STAMPS, during which she kept working with the oddly shaped bacterium, Cyclobacterium marinum.

“Mike Lee, who was on the course faculty, sat down and taught me how to assemble the genome,” she said (they published it in 2019). “And George O’Toole, co-director of Microbial Diversity, allowed me to grow Cyclobacterium in the course. We were able to gather some really cool electron microscopy images with the help of Kasia Hammer from the MBL Central Microscopy Facility. Those images really opened up the whole story.”

Now Sharma is back as an E.E. Just Fellow in the MBL Whitman Center, along with two undergraduates she brought from Hampton. And she is bearing down on a question sparked by discussions during STAMPS: Why does Cyclobacterium have that intriguing shape?

Images that Sharma captured at the MBL of the deep-sea microbe Cyclobacterium marinum led her lab to explore the “whys” of its unusual, deeply coiled shape. From Sharma and Lee, Microbiol. Resource Announc., 2019.

“Most people think there are only two shapes of bacteria: rod and curved. There are many more,” Sharma said. “We started thinking about the ecological benefits or adaptations of Cyclobacterium having this compact, coiled shape. We hypothesize it evolved this shape to avoid predation: It’s too small to eat.”

To test this idea this summer, Sharma is feeding her bacterium to a variety of marine protists (microbes that have a nucleus) to see if they prefer larger or differently shaped cells. “Most of the protists have flagella that create tiny currents. Depending on how the Cyclobacterium is coiled, its shape may help it to escape through the currents,” she said.

Marine Microbes and Mentorship

T’Kiyah Reeves prepares a bacterial culture in Indu Sharma’s lab in Lillie Laboratory. Credit: Dee Sullivan

The students she brought to MBL, Pa-Shun Hawkins and T’Kiyah Reeves, are both Marine and Environmental Science majors. But this is their first exposure to microbiological lab work.

“I really enjoy it,” said Pa-Shun as she prepared a liquid culture of bacteria in Sharma’s lab in Lillie. “It’s very hands-on, sterile, technical. I love seeing the little protists moving in the microscope. A lot of people go into the medical side of microbiology, but I’m interested in how microbes interact in the environment.”

T’Kiyah, for her part, became intrigued by amoebas so Sharma said, “Do you want to study them?” She pointed T’Kiyah toward the MBLWHOI Library to do a literature search and learn different ways to approach their study.

“I think students need to learn the basic concepts, especially through hands-on training, and then they should have the freedom to explore a short question,” Sharma said. “The training wheels come off and advancement of the project lies on their shoulders. Their curiosity is driving them! I think this ownership and science identity is necessary to pursue a career in STEM.”

In her lab at Hampton, undergraduates usually stay one or two years, and the older ones train the new ones. “It becomes a cycle with peer mentoring going on,” she said. “It helps them to create a safe niche. And some have gone on to graduate school.”

Pa-Shun and T’Kiyah are having a great time at MBL, where they are interacting with other undergraduates in the REU- Biological Discovery in Woods Hole program.

“The history of the MBL has really impacted me, even the African-American history here,” said T’Kiyah, who is thinking of pursuing a career in environmental justice. “I am astounded by the amount of work that has come out of this institution. And having the other Woods Hole science institutions nearby – so many people with so many different backgrounds!”

Indu Sharma assists Pa-Shun Hawkins with imaging. Credit: Dee Sullivan

“MBL is a place where science happens, collaborations form, impossible ideas become reality,” Sharma said. “I think it attracts like-minded people who want to think outside the box. Over the years, I’ve developed a lot of personal and professional contacts here.”
 

T’Kiyah Reeves and Pa-Shun Hawkins take a breather by Eel Pond. Credit: Dee Sullivan

“MBL is a place where science happens, collaborations form, impossible ideas become reality,” says Indu Sharma. Credit: Dee Sullivan

The MBL spirit was evident when Sharma gave a research talk at the Whitman Center Brown Bag Lunch series. When she mentioned she had just been awarded her second National Science Foundation grant -- to explore how Cyclobacterium adapts its machinery to changing carbon sources– the gathering of scientists greeted the news with cheers and a round of applause. And then they suggested imaginative ways she might address her research questions!

The MBL is growing. Three new scientists are joining the Ecosystems Center over the next year, and two more will join the Josephine Bay Paul Center for Comparative Molecular Biology and Evolution.

“We have added seven new faculty in the last four years, including Emil Ruff in November of 2018 and Blair Paul in September of 2019,” said David Mark Welch, MBL’s Director of Research. “This is a significant net increase that moves us toward our goal of 29 to 30 resident faculty.”

The scientists joining the Bay Paul Center, Andrew Gillis and Kate Rawlinson of University of Cambridge, were hired in 2020 but the pandemic has delayed their arrival. An announcement of their appointment will come next year.

The three Ecosystems Center hires all have longstanding connections with the MBL and with the coastal field sites where MBL scientists have built deep expertise. “We are very excited to have these outstanding scientists joining the faculty,” said Anne Giblin, director of the Ecosystems Center.

A warm welcome to:

Mirta Teichberg, joining MBL in September 2021
MBL Title: Associate Scientist, Ecosystems Center and Director, Semester in Environmental Science (SES) Program
Current Affiliation: Leibniz Centre for Tropical Marine Research, Bremen, Germany

Mirta Teichberg in her seagrass lab. Seagrass meadows, like coral reefs, provide a critical habitat for a great diversity of marine life, including fish, mollusks and crustaceans. Credit: Tom Vierus, Leibniz Centre for Tropical Marine Research (ZMT)

Mirta Teichberg is a marine ecologist focused on the responses of plants and their associated communities to environmental change. At the MBL, her main research interests will include “studies to promote seagrass recovery on Cape Cod, regionally, and abroad by improving water quality and finding successful methods of seagrass restoration,” she said. “This will involve basic and applied research with local stakeholders from the community.” She also plans to “integrate seagrass restoration with sustainable aquaculture activities.”

“I am very much looking forward to working with the students and faculty of the Semester in Environmental Science program to develop new directions of study while maintaining the history and core values of the program,” Teichberg said.

Teichberg was in residence at the MBL from 2001-2007 while earning her Ph.D. in the Boston University Marine Program. Working with MBL Distinguished Scientist Ivan Valiela, she studied macroalgal bloom dynamics, particularly in Waquoit Bay in Falmouth but also in Europe and South America. “Since then, I usually visit Woods Hole every summer with my family and stop by at MBL to keep up with its scientists and research activities,” she said.

Ketil Koop-Jakobsen, joining MBL in January 2022
MBL Title: Assistant Scientist, Ecosystems Center
Current Affiliation: Alfred Wegener Institute, Wadden Sea Station, List, Germany

Ketil Koop-Jakobsen investigating oxygen, pH and carbon dioxide dynamics in tidal ponds at the Plum Island Ecosystems LTER site in northeastern Massachusetts. Photo: Anne Giblin

Ketil Koop-Jakobsen is a coastal scientist who focuses on the interplay between plants, microbes and soil chemistry. At the MBL, he will be exploring how these interactions affect the major nutrient cycles, carbon storage, and greenhouse gas release. “I am also enthusiastic about exploring new research applications of my optode equipment for imaging oxygen, pH and carbon dioxide in sediments, animal tissues, and other systems, in collaboration with the Woods Hole scientific community,” he said.

Koop-Jakobsen completed his PhD (2008) in the Boston University Marine Program, which was based at the MBL from 1969 to 2008. “Over the years, I kept in contact with the Ecosystems Center and continued to do collaborative research,” he said, particularly in Great Sippewissett Marsh, Falmouth, and at the Plum Island Ecosystems LTER on the northern Massachusetts coast. In fact, Koop-Jakobsen will be coming to Woods Hole this fall to continue his research.

James McClelland, joining MBL in June 2022
MBL Title: Senior Scientist, Ecosystems Center
Current Affiliation: University of Texas at Austin

Jim McClelland in the field at Jago Lagoon, along the Alaskan coast of the Beaufort Sea. Credit: Craig Connelly

James (Jim) McClelland’s interests are in coastal ecosystems, especially the effects of human activity on water, carbon, and nutrient fluxes from land to sea. At MBL, he is “really excited to get involved in the Plum Island Ecosystems LTER,” he said. “My work primarily focuses on biogeochemical transport and processing in watersheds and coastal ocean systems, and the PIE-LTER is a fantastic place to do that.”

McClelland graduated from the Boston University Marine Program in 1998, where he worked with MBL Distinguished Scientist Ivan Valiela. He subsequently worked at the MBL Ecosystems Center from 2001-2006, first as a postdoctoral associate, then as a research associate, and finally as an assistant research scientist. During that period, he mainly collaborated with MBL Senior Scholar Bruce Peterson and former MBL scientist Max Holmes and also worked on a project with MBL Distinguished Scientist Jerry Melillo.

Contact:
dkenney@mbl.edu; 508-685-3525

Coscinodiscus wailesii diatom with an attached Pseudovorticella coscinodisci ciliate epibionts. Streak lines were derived from flows generated by the ciliate epibionts. The source video was captured at 500 frames per second and the image integrates particle paths over a 200 frame interval. From Kanso et al, PNAS, 2021.

One ingenious solution to this challenge is reported this week in Proceedings of the National Academy of Sciences. In low-nutrient environments, marine microbes can clump together and hook up with even tinier cells that have vibrating, hairlike appendages (cilia) on their surface. The beating cilia create microcurrents that can pull up to 10 times more nutrients within the microbes’ reach – thereby serving up a meal through cooperative work.

Even if the ocean is wildly turbulent, microbes can piggyback into consortia for division of labor, says senior corresponding author John H. Costello of Providence College and the Marine Biological Laboratory (MBL), Woods Hole, where much of the research was conducted.

“For all conditions but the most radically extreme mixing, these microbial cells live in fluid spaces that are smaller than the eddies caused by ocean mixing,” Costello says. “In their world, the surrounding fluid is always viscous and they do not experience turbulent eddies as humans feel them.”

The team used a technology called Particle Image Velocimetry (PIV) to measure the direction and magnitude of fluid flows around a photosynthetic marine diatom, Coscinodiscus wailesii, with and without an attached ciliate “partner,” Pseudovorticella coscinodisci. They found that fluid flows generated by ciliary beating can increase nutrient flux to the diatom’s cell surface 4-10 times greater than fluxes to the diatom alone.

This cooperative solution is one way microbes can cope in low-nutrient environments. Another previously known tactic for individual cells is sinking to greater depths, which creates relative motion between the cell and surrounding water and increases its exposure to higher nutrient concentrations.

“Sinking might work well in low-nutrient conditions where mixing will recirculate the cells back up from the depths to the sunlit layers,” Costello says. “That way, the risk to the diatom of sinking might be countered by the probability of being returned to high-light environments. But in low-mixing conditions, forming consortia with ciliates could be a more favorable solution to low nutrient availability.”

Diatoms are among the most important groups of single-celled photosynthesizers for removing carbon dioxide from the atmosphere. Thus, the study helps to illuminate ocean-atmospheric exchanges that have become increasingly important for understanding climate change.

“We have described a collaborative solution – consortium formation – that has evolved on the microscopic scale to allow this large diatom species to successfully persist in low-nutrient waters that would otherwise appear to restrict its success,” Costello says.

Eve Kanso, the paper’s lead author, is at University of Southern California. Costello conducts research at the Marine Biological Laboratory as a Whitman Center scientist. Other co-authors include scientists from University of São Paulo, Instituto Oceanográfico; University of Wisconsin-Milwaukee; University of Texas at Austin; and California Institute of Technology.

Citation:
Eva Kanso, Rubens M. Lopes, J. Rudi Strickler, John O. Dabiri, and John H. Costello (2021) Teamwork in the viscous ocean microscale. Proc. Natl. Acad. Sci., DOI: 10.1073/pnas.2018193118

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The Marine Biological Laboratory (MBL) is dedicated to scientific discovery – exploring fundamental biology, understanding marine biodiversity and the environment, and informing the human condition through research and education. Founded in Woods Hole, Massachusetts in 1888, the MBL is a private, nonprofit institution and an affiliate of the University of Chicago.

Redirects to Turn The Tide art exhibit: https://www.mbl.edu/turn-the-tide/

“Take Five” is an occasional feature in which we pose five questions to an MBL community member about their career, dreams, and passions. Here we profile Patrice O. Yarbough, senior scientist at KBR/NASA Johnson Space Center, 1980 alumna of the MBL Physiology course and, as of July 1, a new member of the MBL Board of Trustees.

Yarbough is the principal investigator for research projects in the Human Exploration Research Analog (HERA), an isolation habitat for simulated, long-duration space missions at Johnson Space Center. She received NASA’s 2020 Silver Achievement Medal for her outstanding leadership in the HERA program. 

A Houston native, Yarbough received her bachelor’s degree in Biochemical and Biophysical Sciences and her PhD in Biochemistry at the University of Houston, and was an NIH postdoctoral fellow at the University of Texas Southwestern Medical Center at Dallas. Prior to contracting with NASA in 2008, Yarbough was director of Strategic Research Collaborations at the University of Texas Medical Branch, and a scientist and research director in the biotechnology industry. Through her leadership in several organizations, Yarbough is dedicated to helping women participate in science, technology, and mathematics at all stages of their careers.

When and why did you decide to become a scientist?

I decided in middle school that I wanted to be a scientist and I never deviated from that. My parents always said, “You're going to have to work to take care of yourself, so why not find something you enjoy doing?” There were no scientists in my family or circle; growing up I didn’t personally know someone with the future job I wanted.  But I was really good at math and knew that I wanted to attend college. I remember earning the 8^th-grade math award. I went to an inner-city high school in Houston and the upper-level science courses were few, but I loaded up on them. In the 11th grade I successfully competed in a Westinghouse nationwide talent search for minority students who had a propensity for the sciences. That landed me four or five weeks at the University of Houston, and I literally fell in love with being in the laboratory. I studied halophytes and I had all sorts of stuff growing in my mom's refrigerator; it was just a fascinating time for me. For college, I chose the University of Houston, where I very quickly zoned in on studying microorganisms. I was not very interested in plants and as my future graduate advisor, Ralph Hecht, once said to me, “You really don't like studying anything that looks back at you.” And I was like, “No, I don't!”

Patrice Yarbough at the University of Houston in 1979, the year before she attended the MBL Physiology course. Photo courtesy of Patrice Yarbough

What question most interests and inspires you to pursue your research?

It’s morphed over the 30 years I’ve been a professional scientist, but the common theme has been translational research. Every step along the way I was focused on, “What do you DO with the science? How do you take your basic research and move it into exploratory research, so that you can apply it to a current unmet need?”

After I finished my doctorate, I worked at a West Coast biotech company for 11 years as part of a molecular virology team. We were working on characterizing the hepatitis E virus, which had not yet been classified taxonomically. We wanted to understand how the virus was regulated so we could create a diagnostic and, ultimately, develop a vaccine for it. That was my driver: I wanted to be a part of the success of coming up with a preventative or therapeutic.

Currently at NASA in HERA, we are interested in the impact of confinement, isolation, and communication delays with Mission Control on the behavioral health of astronauts who are on long-duration missions. Our HERA research subjects are simulating a journey to Phobos, the moon of Mars, which would be a multi-year mission. After two weeks of training, they are in confined isolation inside of HERA for 45 days.

Our team includes a science team, a medical team, and an operations team to carry out a HERA campaign, which includes 4 missions and 16 human subjects. The clinical and behavioral psychologists are measuring indicators of stress, everything from changes in facial expression to changes in performance. Over the years we have included more physiological parameters to measure changes in the human response to stress. For example, if we can identify tangible biomarkers -- some analytes in the blood that indicate response to stress -- and we can compare those with clinical behavioral data, it will be a win-win. The ultimate goal is to be able to recognize the human response to stress early, and to develop countermeasures to manage the stress that you can send to the astronauts, or train them to use.

What I love about the studies is they also have general population applications. For example, everything we learn about confined isolation will have applications for the military, for understanding post-traumatic stress disorders in veterans. Right now, we are in the middle of a Covid-19 confinement and so many people are having difficulty managing it. So I feel confident that our research at NASA is a good use of taxpayers’ dollars, because it will have broad implications.

If you can invite three specialists in your field, living or deceased, to dinner, who would you choose?

The first person that comes to mind is Jonas Salk, an American born to an immigrant family. To have developed the polio vaccine in the early 1950s when so much of the technology that we have now didn’t exist ... I would love to pick his brain about “How did you even think about asking that first research question?” It all starts with something that is a curiosity to you.

The second person is Russell Brown, an African American scientist at the Tuskegee Carver Institute in Alabama. When Salk had identified what he thought was the candidate polio vaccine, they were looking for a way to test its effectiveness and they needed human cells. Tuskegee had HeLa cells, the cancer cells taken from Henrietta Lacks at Johns Hopkins Hospital. A little-known story is that Russell Brown used those HeLa cells to show that the polio vaccine produced enough antibodies to fight off the virus. What really is amazing is how quickly Brown learned how to do tissue culture and how the Tuskegee scientists, led by Brown, grew a large quantity of HeLa cells to be distributed to medical laboratories around the country [to test batches of vaccine]. This was in the segregated 1950s, so it was quite difficult for this Black man to travel to the north for the tissue culture training. It’s not like Brown could just check into any hotel at that time. It was really rough. But he did it. It’s just an amazing story, one of so many examples of excellence in laboratory skills and willingness to work on behalf of science.

The third person is Kizzmekia (Kizzy) Corbett, an African American woman in her 30s who was on the National Institutes of Health team for the development of the early COVID vaccine. I would love to have breakfast, lunch, and dinner with her. I am sure that we have much in common, but her path had several educational options that weren't there when I was going through the ranks about 30 years earlier. Her passion is the interface between virus research and public health measures to help the fight against infection and global illnesses. By the way, for every virus that has a name, there are legions that don’t yet. We have to figure out how to protect human health against those, too.

How did you hear about the MBL, and what impact has it had on your life or career?

The MBL has always been known as a gem of scientific excellence; people all over the world go there for its immersive research courses. So in my senior year when my advisor said, “You should apply for the Physiology course,” I did. I'm pretty sure the fact I had worked in the lab since my sophomore year helped me get in; most of the Physiology course students already had at least one year of graduate school. But I fit in just fine.

After the six-week course, I was accepted into a four-week post-course program where students did a mini project. The MBL was 10 glorious weeks for me. It was priceless. You meet students who have intellectual interests like yours and you walk away with that plus so much more. I had never worked that hard before; we literally worked in the lab around the clock. But there's a little bit of magic in the air there, because everybody wants to do it. After I came home, all I could talk about was the MBL for months. MBL was the seal for me.

Years later, in 2018, I wrote a letter to the MBL saying I had not forgotten my amazing experience there and that I wanted to help send a minority student, preferably female and African American, to one of the prestigious summer courses. I was quite sad when I was told that no African Americans had been accepted to the Physiology course. I thought, “It’s been nearly 40 years since I was there and I was the only African American then. So what's wrong here?” I was informed about the MBL SPINES course, a summer program in neuroscience for underrepresented minority students; I funded a student in that program.

And then last year I was called to discuss a position on the MBL Board of Trustees. What sold it for me was when the chair of the board, President Zimmer of University of Chicago, explained to me his vision of creating new programs for inner-city Chicago students. I thought “Between that and increasing the diversity of the students at the MBL, so more can have that amazing experience that I had in summer 1980, that's going to keep me pretty busy as a Trustee.” So I accepted!

Outside of your work, what are your passions?

Number one is diversifying the science work force. Frankly, I've been doing that since I was a graduate student and I would reach back to the high schools, because I saw so few students in the natural sciences at the university that looked like me. Why aren't they here? Some of it is because they simply don't know about science and they maybe don’t know a scientist. When I went to private industry, I used my free time to reach out to the universities. Later, I chaired a women’s faculty organization at the University of Texas Medical Branch. The goal was to help women who choose academic science careers to stay in the field. I've been very involved in the Association for Women in Science since I was a graduate student. And I am looking forward to my appointment to the MBL Board of Trustees. This, too, will help me continue with something I started long ago: To bring more women and underrepresented minorities into science careers. And the best place in the world to work on that is at the MBL, the gem of scientific excellence in research and discovery.

The 1980 MBL Physiology course. Patrice Yarbough is front row, second from right.

Interview edited by Diana Kenney