Helping teachers bring marine science to middle and high schools

April 6, 2018 | Atlanta, GA

Frank Stewart and Darren Joshua Parris are the recipients of the 2018 Education Partnership Award for their collaborative Summer Workshop in Marine Science (SWiMS) program. The award, from the Center for Teaching and Learning, recognizes genuine and substantial partnerships between the faculty and students of Georgia Tech and the K-12 community. Also receiving the award is their K-12 partner Jennifer Jones, a chemistry teacher at Rockdale County High School.

Stewart is an associate professor in the School of Biological Sciences and the advisor of Parris, a fifth-year Ph.D. student.  

“I am honored and humbled to have the SWiMS partnership recognized by this award,” Stewart says.  “SWiMS has been one of the most rewarding experiences of my career, largely because it fosters connections to people like Jennifer and Josh.  These are the connections that are honored here and that are so critical for advancing science literacy in our schools and elsewhere.”

Stewart conceived SWiMS in 2012 as a way to promote understanding of ocean science and microbiology. With oil spills, coral reef collapse, sea level rise, and ocean acidification often being front-page news, he believes the general public should have a basic understanding of these phenomena. For Stewart, these issues are just as important to policymakers and the general public as they are to researchers.

SWiMS is a five-day workshop to help middle and high school teachers develop curricula and project-learning exercises to teach marine science in the context of global change. “My overarching goal was to use marine science to enhance earth and life science education in middle and high schools, specifically targeting those in academically underperforming districts in Fulton County,” Stewart says. SWiMS draws on the expertise of marine scientists at Georgia Tech and education experts at Georgia Tech’s Center for Education Integrating Science, Mathematics, and Computing (CEISMC).

Parris joined the program in summer 2015. “To put it bluntly, this program would likely not have been possible without Josh,” Stewart says.

Parris has roles throughout all stages of the program. He wrote, edited, and tested several of the education modules used in SWiMS. During workshops, he serves as instructor, preparing rigorously to guide the workshop participants.  

SWiMS includes a two-day trip to Sapelo Island, a barrier island located in McIntosh County, Georgia. The trip provides participants firsthand experience and an opportunity to collect samples to take back to their classrooms. For this trip, Parris has served as primary field team leader, planning the logistics as well as conducting activities.

Most impressively, Stewart says, Parris continues to engage with teachers after the workshop. He helps teachers with curriculum-related problems arising during the school year and continues to prepare modules for teachers upon request. He recently visited Central Gwinnet High School to lecture about marine pollution.

 “I am very grateful to have been a part of the SWiMS program,” Parris says. “I have been able to see firsthand the positive impact scientists can have outside of research.  SWiMS is an awesome example of using partnerships between scientists and educators to advance science education in schools.”

Jones began as a participant in the workshop in 2015, returned as a mentor in 2016, and joined again in 2017 as an education consultant. A veteran teacher of 16 years, Jones had a keen sense of which concepts would translate into the classroom and which wouldn’t. Her unique insight was vital to identifying and troubleshooting obstacles and translating the curricula into targeted lesson plans. She also helped other teachers develop classroom-specific plans.

The collaboration of a scientist, a Ph.D. student, and a high school teacher has yielded remarkable outcomes. “The SWiMS program has enhanced my instruction in the classroom,” Jones says. “My students were able to understand that topics in science overlap: marine science touched Earth science, which touched environmental science, which touched chemistry. I am grateful to all the participants; they have inspired me to explore and expand my teaching so that students may experience science in a memorable way.”

For More Information Contact

maureen.rouhi@cos.gatech.edu

A. Maureen Rouhi, Ph.D.
Director of Communications
College of Sciences

Innovating, advocating for students’ health and wellness

April 9, 2018 | Atlanta, GA

Georgia Tech has selected Teresa Snow as a recipient of the 2018 Geoffrey G. Eichholz Faculty Teaching Award, administered by the Center for Teaching and Learning. A senior academic professional in the School of Biological Sciences, Snow oversees the required wellness courses APPH 1040, Scientific Foundations of Health,” and APPH 1050, “Science of Physical Activity and Health”; teaches graduate-level applied statistics; and serves on curriculum-related committees.

The award recognizes faculty who provide outstanding teaching to students in core and general undergraduate courses and help students establish a solid foundation for their education at Georgia Tech. Colleagues say Snow empowers students to prioritize self-care and become critical health consumers.

Undeterred by the obstacles associated with teaching undergraduates in large lecture classes, Snow challenges students to think beyond the classroom and apply the knowledge in ways that will lead to healthier lifestyles and a healthier campus community. Innovation is the basis of her achievements.

For example, Snow transformed the required wellness course APPH 1040.

The course is unique because it directly touches students’ lives. It covers topics such as sleep, nutrition, and exercise, as well as sensitive issues facing students, such as mental health, sexual violence, and self-esteem.

To help students navigate these complicated matters, Snow provides a “safe and caring learning environment,” a colleague says. “She spends a great deal of time with students listening and recommending campus resources.”

“Teresa is highly respectful and honoring of all individuals… a rare and unique characteristic,” another colleague says. She goes out of her way to follow up and see how students are doing. In turn, students continue to contact Snow long after they have graduated to inform her of their accomplishments. A few of them are pursuing careers in health, crediting Snow for inspiring them.

Snow wanted the wellness requirement to provide students with additional opportunities to use practical knowledge to maintain a balanced, healthy lifestyle. So she partnered with members of the Student Government Association and the Campus Recreation Complex to create APPH 1050, which provides physical activity instruction. This course has been wildly successful, reaching maximum capacity ever since its inception. It is now also offered in the Pacific Study Abroad program.

Snow’s advocacy for health and well-being reaches beyond the classroom. She served on the executive committee for Georgia Tech’s first health and well-being coalition, Go T.E.C.H. (Teams Encouraging Campus Health). She currently is faculty advisor to Relay for Life at Georgia Tech, a year-long fundraising effort for the American Cancer Society.  

“The most rewarding part of my job is working with Georgia Tech students,” Snow says. “They have a remarkable level of motivation, resourcefulness, and desire to make a difference. My role as a teacher is incredibly satisfying when I find ways to engage their enthusiasm and passion to learn.” 

For More Information Contact

maureen.rouhi@cos.gatech.edu

A. Maureen Rouhi, Ph.D.
Director of Communications
College of Sciences
 

Compassionately, tirelessly helping students learn

April 10, 2018 | Atlanta, GA

Georgia Tech has named Shana Kerr to receive the 2018 Class of 1940 W. Roane Beard Outstanding Teacher Award. An academic professional in the School of Biological Sciences, Kerr adds this award to two undergraduate advising honors she received in 2017 from Georgia Tech and from NACADA: The Global Community for Academic Advising.  

Students are foremost for Kerr. From implementing student-centered teaching initiatives to mentoring students outside of class, Kerr demonstrates remarkable compassion for her students and passion for teaching.

Kerr aims to make every class she teaches to be as student-centered as possible, favoring interactive teaching over a lecture-only approach. She modifies class activities so that students engage with the course materials themselves instead of just passively listening.

Now in her sixth year of teaching at Georgia Tech, Kerr continues to adapt and use active learning strategies so that students don’t slip through the cracks, especially for big classes held in a lecture hall.

The main engagement strategy she uses for large classes is the “flipped” class. Students complete short readings, watch online videos, and take practice quizzes before class, and then during class, they work through activities and question sets in small teams to test and integrate their knowledge. For small classes, like Bioethics, she uses real-life case studies as the context and hook for discussing and applying course concepts.

Kerr’s education initiatives – for example, a project-based research experience for a laboratory course – have had career-changing impacts on students. Many students have switched their career focus from aspiring to be medical doctors to conducting scientific research because of Kerr’s influence.

Colleagues say that Kerr’s compassion when working tirelessly with students is what truly makes her stand out. When students aren’t performing to their potential, Kerr notices, and she takes action. She invites students to office hours, checks in with their academic advisors, and makes referrals to the Dean of Students when necessary.  “She shows endless patience until students learn concepts to her satisfaction,” a colleague says.

“One of the most inspiring aspects of working with Georgia Tech students is their continual motivation to acquire new knowledge and make new mental connections,” Kerr says. “I aim to challenge my students and to provide the resources and scaffolding they need to meet and exceed these and future challenges. I’m humbled to be recognized for my teaching efforts by the Class of 1940 W. Roane Beard Outstanding Teacher Award.”

For More Information Contact

maureen.rouhi@cos.gatech.edu

A. Maureen Rouhi, Ph.D.
Director of Communications
College of Sciences

Here's a thought to make your skin crawl: Viruses are the most abundant entities on the planet by far. And trillions upon trillions fall from the sky every day, according to a recent study that was the first to tell us just how many viruses float above the Earth. Now you know why School of Biological Sciences Professor Joshua Weitz was one of three researchers calling for a better understanding of viral ecology in a 2017 editorial in Nautilus. There is a silver lining to this virus deluge; some of them may actually be good for their hosts.

Maggots aren't the cutest creatures. But David Hu, who is affiliated with the School of Physics and the School of Biological Sciences, spends time with them in a lab, studying their motion to determine how they are able to eat food so efficiently. Hu's lab is not a creepy, crawling maggot madhouse without a purpose: these creatures may be harnessed for breaking down waste. 

Georgia Tech helped develop his genuine passion for medicine and service

May 1, 2018 | Atlanta, GA

Before going to college, Akinade A. Ojemakinde spent his entire life in Southwest Georgia with his father, mother, and older sister. “From my very first day of school to my very last, I was continuously surrounded by high-achieving classmates and friends, as well as supportive teachers and family,” Ojemakinde says of his high school days, in Lee County High School, in Leesburg, Georgia, where he also played trombone in the band and fullback in the soccer team.

Because he wanted to go to medical school, finding a college with a highly rated biology department and research opportunities was his top priority. “Being one of the most rigorous, top-tier research institutions in the nation, Georgia Tech quickly caught my interest,” Ojemakinde says. In addition to Tech neither being too far nor too close to his family, receiving a full-ride merit scholarship from the Stamps President’s Scholarship Program sealed the deal for him to attend Georgia Tech.

Now, Ojemakinde is graduating with a B.S. in Biology, one step closer to his dream of becoming a surgeon.

How did Georgia Tech meet your expectations?

Georgia Tech provided excellent opportunities to conduct high-quality, stimulating research, as a part of courses and in the lab of Patrick McGrath in the School of Biological Sciences.

Tech lived up to the hype and repeatedly challenged me academically; thanks, organic chemistry!

Not only did my research and tougher courses force me to recognize and understand my personal strengths and weaknesses, but they also taught me to ask for assistance more quickly and to work more collaboratively.

"I believe that the science foundation I obtained at Georgia Tech is much stronger than those of my graduate-school peers. Georgia Tech has prepared me well for medical school and my career as a physician."

What are your proudest achievements at Georgia Tech?

In addition to consistently making the Dean’s List and receiving Faculty Honors, I am proud to have served the American Red Cross Club at Georgia Tech as the chair of campus blood drives for three years.

This position combined my passion for donating with the responsibility of ensuring that my peers could donate as well. It was challenging to organize blood drives and reach high donation goals, but I enjoyed planning and facilitating many successful blood drives.

I had great success in the McGrath lab, helping with directed-evolution experiments, analyzing experimental results, and conducting next-generation sequencing to identify the genetic changes responsible for differences in the fitness of the experimental worms C. elegans. My work will lead to a publication and insight into how genetic variation contributes to fitness and the basic rules of metazoan evolution.

Which professors or classes made a big impact on you?

I had Shana Kerr as an instructor nearly every semester. She challenged me in the classroom, presented me numerous opportunities and supported me outside the classroom, and clearly demonstrated her desire for me and others to succeed. She is a significant factor in my success at Georgia Tech.

Courses like Organic Chemistry I and II showed me that I would not enjoy being like Walter Whitman from Breaking Bad. Others like Human Anatomy and Human Physiology significantly influenced my decision to go to medical school and gave me a glimpse of what I can look forward to.

What is your most vivid memory of Georgia Tech?

I’ll never forget playing indoor soccer during my freshman year! I was so happy to play indoor for the first time and join Tech’s soccer community. While playing, however, I collided with an opposing player, tore my left ACL (anterior cruciate ligament), and needed orthopedic surgery to repair it. Nevertheless, this accident couldn’t keep me off the pitch for long!

How did Georgia Tech transform your life?

I used to feel as if I was memorizing facts just to pass exams, and I did not see how certain classes were applicable to my future. Being involved in research changed my perception about the classroom. I now view it as a resource to help me in the lab. This attitude has improved my comprehension and retention of what is taught in class.

My years of work in the McGrath Lab led not only to intellectual, but also to personal, growth. Having to effectively communicate experimental plans and results improved my speaking skills and ability to converse with others about science.

I developed genuine passion for service and medicine. My involvement with the American Red Cross Club at Georgia Tech, the Georgia Tech Excel Program, and the School of Biological Sciences strengthened my belief in the importance of service and love for biological sciences.

Georgia Tech solidified my decision to pursue medicine and dedicate my life to the well-being and health of my community.

What unique learning activities did you undertake?

I was exposed to medicine in practice by working as a medical scribe in the Emergency Department of Atlanta Medical Center. Working two 10-hour night shifts a week in a fast-paced environment transformed my life. With guidance from skilled physicians, I became fluent in medical terminology and confident in my ability to perform in a professional, medical environment.

Doing research in the McGrath Lab for two years was one of my most meaningful and impactful experiences. I had to learn by observing or following the careful instructions of a graduate student in the lab. When I acquired enough expertise, I eventually taught my lab peers what I learned. The ability to apply and teach what I learn will be of great use in medical school and beyond.

What advice would you give to incoming undergraduate students at Georgia Tech?

Be intentional with your time, and learn how to balance your obligations as quickly as possible. There is so much class work to do and so much fun to be had that it is impossible to do everything.

If one makes a conscious effort to balance academic, social, and sleep (please get some sleep!) obligations, everything else will fall into place.

Where are you headed after graduation?  

I am headed to Emory University School of Medicine. I wish to specialize in either orthopedic or cardiothoracic surgery.

I believe that the science foundation I obtained at Georgia Tech is much stronger than those of my graduate-school peers. Georgia Tech has prepared me well for medical school and my career as a physician.

For More Information Contact

maureen.rouhi@cos.gatech.edu

A. Maureen Rouhi, Ph.D.
Director of Communications
College of Sciences

Initially intimidated by Tech, she grew to believe in herself and succeed at Tech

May 3, 2018 | Atlanta, GA

“I was raised a Yellow Jacket,” says Elizabeth Ann “Lizzie” Stubbs. She’s referring to her parents and grandfather, who all graduated from Georgia Tech. She knew all the cheers and chants by heart. But still, she wasn’t sure if Georgia Tech was where she should be. “Honestly, I was intimidated by Tech and I was very close to going to [the University of Georgia],” Stubbs says, afraid that she wouldn’t be able to maintain a high GPA.

But her mind changed one day. At an information session for students admitted to the College of Sciences, she asked a female student about her personal experience at Tech. The student assured Stubbs that it was possible to succeed at Tech. “I was sold,” Stubbs says.

Stubbs went to high school at Pinecrest Academy, in Cumming, Georgia. As the third oldest of seven siblings, she gained independence and a strong work ethic at an early age. These skills enabled her to work hard and succeed. Now she is graduating with a B.S. in Psychology, with a minor in Biology.

What is the most important thing you learned at Georgia Tech?

To believe in myself.

Georgia Tech is rigorous, as I expected. My biggest fear was that I wouldn’t succeed academically. But after my first semester, I proved to myself that I am capable, and that knowledge helped me get through some tough semesters. Tech has shown me time and again that I am capable of achieving my academic and other goals if I am willing to put in the work.

I also love the emphasis on innovation and research, which fosters progress and ignites people’s passions. I’m amazed to learn about the projects and inventions fellow students, faculty, and alumni are working on.

"Georgia Tech has prepared me well for the academic rigor and fast-paced atmosphere that I expect I will experience in PA [physician assistant] school. From conversations with alumni currently in PA school, I have learned that they were well-prepared because they had already established good study strategies, time management skills, and work ethic at Tech."

What are your proudest achievements at Georgia Tech?

One of my proudest achievements is receiving the Leddy Family Scholarship. I was honored to be recognized for my hard work, and it took a huge financial burden off my shoulders. I am incredibly grateful to Mr. and Mrs. Leddy for their generosity and support.

It was awesome to learn that a paper of my research group was accepted for publication in the Journal of Autism and Developmental Disorders. I was listed as a coauthor for data analysis. The study we reported assessed the eye contact behavior of typically developing children versus children diagnosed with Autism Spectrum Disorder during play and conversation segments.

Which professors or classes made a big impact on you?

I loved Human Anatomy, a class taught by Adam Decker. I loved reading the textbook, and studying the material. I found the information so fascinating, and it helped confirm my decision to study medicine. That class was a lot of work, but Decker always kept lectures lively and informative.

What is your most vivid memory of Georgia Tech?

The Aug. 21, 2017, solar eclipse.

It was awesome to see students, faculty, and staff admiring and enjoying this rare occurrence all out on Tech Green. We were all just geeking out together and it was awesome!

How did Georgia Tech transform your life?

Tech helped shape the path that I am on and helped me grow as a person.

I volunteered to do outreach through programs like Hands on Future Tech and Step into STEM (science, technology, engineering, and mathematics).

This past winter break I went on a medical mission with Volunteers Around the World. We traveled to the Dominican Republic and set up mobile clinics in various villages. It was such an incredible experience, and I plan to continue going on medical missions and finding ways to serve those most in need.

Being involved in research since my second year has been one of the greatest things I about my time here.

Each of these opportunities required me to step outside of my comfort zone. I grew and learned valuable skills.

What unique learning activities did you undertake?

I never planned on doing research because I didn’t think I would enjoy it. But an older student told me about the lab she worked in and I was intrigued. After touring the Child Study Lab, I knew I was meant to work there.

Working at the Child Study Lab, with Agata Rozga of the School of Interactive Computing, is one of my best experiences at Tech.  The lab is also one of the best work environments I’ve encountered. Working in this lab for three years now has helped me grow. It taught about psychology and research in general. I learned a lot about myself. By stepping outside of my comfort zone, I gained confidence.

What advice would you give to incoming undergraduate students at Georgia Tech?

Yes, Tech is hard, but you are more than capable of succeeding if you put in the work.

Do the homework, study the material outside of class time, and get help if you need it. Be confident in your skills and abilities. That you were accepted into Tech means you have the ability to excel here.

Step outside of their comfort zone and try new things. You will gain valuable experiences and learn about yourself along the way.

Where are you headed after graduation?

I will take a gap year, working as a medical assistant to gain patient care hours before going back to physician assistant (PA) school. Georgia Tech has prepared me well for the academic rigor and fast-paced atmosphere that I expect I will experience in PA school. From conversations with alumni currently in PA school, I have learned that they were well-prepared because they had already established good study strategies, time management skills, and work ethic at Tech.

For More Information Contact

maureen.rouhi@cos.gatech.edu

A. Maureen Rouhi, Ph.D.
Director of Communications
College of Sciences

Professor Emeritus Phil Sparling's newspaper columns are now a book of essays

May 7, 2018 | Atlanta, GA

By Mallory Rosten, Student Communications Assistant, College of Sciences

School of Biological Sciences Professor Emeritus Phillip Sparling has published his first book of creative nonfiction. “The Sneakers in the Closet and Other Essays” explores the intersection of sports, health, and life. It’s a collection of 24 stories (and a few poems), compiled and re-edited, from newspaper columns Sparling wrote over several years.

In the eponymous first essay, Sparling reminisces on a childhood full of sports and physical activity. As a kid, he was constantly on the move, taking detours from bicycling  to school to climb trees or scale a wall. He can measure the phases of his youth by sports: four square and kickball in elementary school; neighborhood pickup games of football, basketball, and baseball through junior high school; and then cross-country and track in high school. .

Maybe that’s why Sparling dedicated his research to unraveling connections between fitness and health. His early research focused on investigating relationships among endurance training, resistance training, energy balance, body composition, and cardiovascular health. In the mid-1990s, his research shifted to understanding physical activity and eating patterns as modifiable health behaviors.

Sparling joined Georgia Tech in 1979 as an assistant professor in what was then the Department of Physical Education. When he retired almost 30 years later, it had become the School of Applied Physiology, which merged with the School of Biology to form the School of Biological Sciences in summer 2016. During his last decade at Tech, Sparling taught a large lecture “Personal Health” course and the graduate-level courses “Exercise Physiology” and “Physical Activity and Health.”

In retirement, Sparling broadened his writing to include narrative nonfiction.  “It allows more creativity than scientific and technical writing,” Sparling says. He began publishing essays in Smoke Signals, the local paper of Big Canoe, a mountain community about one hour north of Atlanta. His editor and friends encouraged him to publish the essays in a book. In “The Sneakers in the Closet and Other Essays,” he reflects on various topics – from play, exercise, and fitness to diet, drugs, and doctors.

“My aim is to engage and educate by sharing stories, including personal reflections on growing up, finding a career and growing older,” Sparling says, “and to show how role models shape our health and well-being.” He hopes that people who read his stories walk away “better informed, empowered, and thankful.”

The book’s proceeds go to the Richard Gay Israel Health and Exercise Science Scholarship at Colorado State University.  Sparling describes his late colleague, Richard Gay Israel, as “salt-of-the-earth and a natural leader.”

At Georgia Tech, Sparling expanded the study of health and exercise by establishing and directing the Exercise Physiology Laboratory, developing the Ph.D. program in applied physiology, and advocating for the integration of behavioral science with biomedical science. For a decade, he served as chair of Georgia Tech’s Institutional Review Board for the protection of human subjects in research.

Sparling also had sabbatical experiences as a senior scientist with the Centers for Disease Control and Prevention and a Fulbright Scholar at University of Cape Town Medical School, in South Africa. In addition, Sparling was a leader in professional societies, including the American College of Sports Medicine and the Society of Behavioral Medicine.

 “I'm proud to have spent my career at Georgia Tech – a top-notch institution with excellent students, staff, and faculty,” Sparling says.

In addition to writing and reading, Sparling gardens and hikes with his wife, Phyllis, in the Georgia foothills where they live. They enjoy travel at home and abroad. And he continues to write columns to nudge folks to healthier ways and a fuller life.

For More Information Contact

maureen.rouhi@cos.gatech.edu

A. Maureen Rouhi, Ph.D.
Director of Communications
College of Sciences

For the first time, scientists determine the reach of quorum sensing in an infection

May 31, 2018 | Atlanta, GA

“A large part of my research is thinking about how bacteria communicate,” says Sophie Darch. The postdoctoral researcher works with School of Biological Sciences Professor Marvin Whiteley, studying the social lives of bacteria.

Darch observes the conversations of bacteria, which take place via molecules they release into the environment and are sensed by other bacteria. In Darch’s experiments, completed messages are marked by the red-to-green change in the color of the bacterium sensing the molecule.

By sending and receiving extracellular signals, bacteria sense their neighbors. When enough bacteria are in the conversation, things happen. Sometimes it leads to changes in virulence or ability to establish an infection. The phenomenon is called quorum sensing.

Yet little is known about how quorum sensing proceeds during infection “Much of what is known about quorum sensing,” Darch says, “comes from studies of large populations of bacteria in an environment that does not compare with the natural infection site.” In infections, for example, bacteria are often found in small, dense clusters, called aggregates. “It’s really important for us as scientists to think about what bacterial growth looks like in an infection,” Darch says.

In a paper in the Proceedings of the National Academy of Sciences USA, Darch, Whiteley, and colleagues describe for the first time how close bacteria need to be to “talk” with each other in an environment similar to an infection. Their findings could reveal new ways to disrupt bacterial signaling and provide other targets to treat infections.

The work was supported by the National Institutes of Health, the Cystic Fibrosis Foundation, Human Frontiers Science, and the Welch Foundation.

Cystic Fibrosis Model

The study uses an environment similar to the chronic infection of the cystic fibrosis (CF) lung.

CF is a genetic disease that causes buildup of sticky mucus in the lung. The viscous setting CF creates makes the organ prime real estate for disease-causing bacteria. Among the most prevalent of these in the CF lung is Pseudomonas aeruginosa.

P. aeruginosa infections pose a huge problem because they are resistant to many antibiotics and are difficult to treat. Often P. aeruginosa infection is what causes death among patients with CF.

The team used a synthetic CF sputum media (SCFM2), based on the makeup of lung secretions from patients. In nutritional content and physical form, the medium is similar to sputum from the lung. Importantly, P. aeruginosa forms aggregates in SCFM2 that are similar in size to those observed in CF lung tissue.

3-D Printed Bacteria

To begin to answer the question “How close do you have to be to talk to your neighbor?” the team collaborated with Jason Shear at the University of Texas, Austin. The Shear Lab had developed a micro-3D-printing platform that could be used to engineer the growth of bacteria to mimic infections.

Bacteria are not uniformly distributed in infections. “Instead we see bacterial aggregates that vary in size and can be separated by large distances,” Whiteley says. “We needed an experimental method to engineer these types of infection landscapes in the lab.”

Using Shear’s micro-3D-printing platform, the team printed bacterial aggregates of exact positions and sizes.

A typical experiment starts by enclosing one producer cell in a picoliter-sized trap, using micro-3D-printing. After multiple cell divisions, the population fills the volume of the trap. Then SCFM2-containing aggregates of responder cells are overlaid the porous trap.

They observe the one-way flow of signals from aggregates in a trap (producers) to aggregates outside receiving signals (responders). They could see the response of completed conversations by responders changing color from red to green.

Implications for Cystic Fibrosis

“We found that bacterial aggregates slightly larger than those in CF lung – containing about 2,000 cells – were not large enough to signal to other aggregates,” Darch says.

Prior to this study, it was thought that bacterial signaling could occur over extended distances. However, in the CF lung, small populations of bacteria are scattered across a large volume and separated by large distances. Aggregates are unlikely to “talk” to each other. 

It took aggregates containing at least 5,000 cells to successfully send signals to neighbors as far away as 176 micrometers. “These aggregates are around five times the size of the average aggregate observed in CF lung tissue” Darch says “From these data, communication is likely confined within an individual aggregate rather than being a population-wide phenomenon”.

Among CF patients who are at least 20 years old, 80% are infected with P. aeruginosa. “Infection with P. aeruginosa remains a significant clinical problem in immunocompromised patients, particularly those with CF,” Darch says. “Understanding better how bacteria communicate has the potential to find ways of disrupting the communication and potentially diminishing bacterial virulence.”

“The study provides benchmark data for how quorum sensing might proceed in an environment similar to the CF lung,” says Whiteley, who is a member of the Parker H. Petit Institute for Bioengineering and Bioscience. “In different settings, where P. aeruginosa and other bacteria exist as aggregates of different sizes, communication may look different. Future studies will involve experimental and modeling work to further examine the spatial parameters of quorum sensing in CF and other infections, such as a chronic wound.”

Figure Caption

(Left) Rendered confocal laser-scanning micrograph of a micro-3D-printed trap (red)  surrounded by P. aeruginosa aggregates responding to quorum-sensing signals (green) in a synthetic CF sputum media (SCFM2).

(Right) Rendered confocal laser-scanning micrograph of responding (green) and non-responding (red) P. aeruginosa aggregates formed in a synthetic CF sputum media (SCFM2).

For More Information Contact

maureen.rouhi@cos.gatech.edu

A. Maureen Rouhi, Ph.D.
Director of Communications
College of Sciences

With Ford Foundation support, Kennda Lynch seeks to learn more about microbes that consume rocket fuel as energy source

June 19, 2018 | Atlanta, GA

Liquid water on Mars fired everyone’s fancy in 2015. Water on Mars today exists in the form of hydrated perchlorates, said the researchers who led the work. They include James Wray, an associate professor in the School of Earth and Atmospheric Sciences (EAS).

The finding boosts the possibility of life on the red planet. Water tied to perchlorate meets life’s two needs: water and energy. Perchlorate emits huge amounts of energy when it reacts. For this reason, its salts are ingredients of rocket boosters and fireworks.

Perchlorate as Food for Microbes

Some organisms use perchlorate as an energy source. So-called perchlorate-reducing microorganisms (PRM) would likely live in places where perchlorate naturally occurs. Yet coexistence of PRMs with naturally occurring perchlorate has not been detected until recently.

One likely place where such coexistence may occur is Pilot Valley, in the Great Salt Lake Desert of Utah. Pilot Valley is a hypersaline, perchlorate-rich, and closed basin. It loses water mainly from evaporation.

Yet perchlorate vanishes from Pilot Valley to an extent that cannot be explained by water loss, says Kennda Lynch. She’s a postdoctoral researcher working with Wray and School of Biological Sciences Professor Frank Rosenzweig.

Perchlorate is soluble in water, but it will not evaporate with water. Perchlorate salt residues should accumulate as water evaporates. Yet Pilot Valley shows a decline of such salt remains. The perchlorate is just disappearing.  

Lynch believes PRMs in Pilot Valley must be using the perchlorate. While doing her Ph.D., Lynch found the first known coexistence of PRMs and naturally occurring perchlorate in Pilot Valley. Because no one knows what these PRMs are, Lynch will spend the next year finding out. Supporting her work is a recently announced Ford Foundation fellowship.

Ford Foundation Fellowship

“I’m extremely honored to be a Ford Fellow,” Lynch says. “This funding will allow me to continue this important research, which will aid the search for evidence of life on other planets.”

Ford Foundation Fellowship Programs seek to increase diversity in academia by increasing ethnic and racial diversity. As a fellow, Lynch will gain access to one of the largest communities of academic professionals committed to creating and fostering diverse environments in higher education.

The fellowship presents a “unique opportunity to forge connections with extraordinary individuals as I continue efforts to broaden diversity within the field of astrobiology,” she says.

Lynch’s Ford Foundation research aims to find out what microbial communities use perchlorate. What are the mechanisms at their disposal?

Lynch will examine whether active perchlorate metabolism takes place in Pilot Valley. If so, what other metabolic processes occur when that process is on?

Then she will use the findings to help define a model for perchlorate-driven life on Mars. 

Filling the Knowledge Gap

The work will help NASA’s Mars Exploration Program understand the extent of habitable environments on Mars, including energy sources that could drive microbial systems. “Perchlorate is one of the most abundant and most energetic metabolic resources on Mars,” Lynch says. Yet basic questions abound about its use to support life in a place that looks like Mars.

Working in Pilot Valley – an Earth stand-in for Mars – Lynch aims to fill the knowledge gap. She will run experiments to detect perchlorate use. She will apply state-of-the-art techniques to find genes for, and expression of, perchlorate metabolism. She will also isolate PRMs. 

Lynch will continue to work with Wray and Rosenzweig. However, she will be based mostly in the lab of EAS Assistant Professor Jennifer Glass.

“My lab members and I are very excited to have Kennda join us,” Glass says. “Kennda will bring a new perspective on Mars’s relevance to our group. Serendipitously, we have cultivated microbes similar to PRMs in our recent studies, and we look forward to helping Kennda grow new, exciting microbes from Pilot Valley.”

For More Information Contact

maureen.rouhi@cos.gatech.edu

A. Maureen Rouhi, Ph.D.
Director of Communications
College of Sciences

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