Graduate student hopes quorum sensing research will have broad impact
Whenever we tweet, post on Facebook or share a picture on Instagram, we call that social networking. Bacteria also have a way of networking, and graduate student researcher Revathy Ramachandran is trying to better understand the process.
A sixth year graduate student in biological sciences in the College of Science, Ramachandran is working with Ann Stevens, a professor in that department, to study the phenomenon of quorum sensing and how it is used by the plant pathogenic bacterium Pantoea stewartii, which causes Stewart’s wilt in corn plants.
Quorum sensing is the process by which a bacterium is able to sense a fellow bacterium nearby and coordinate expression of genes to form specific proteins. In doing so, the proteins can then become the cause of various diseases. By better understanding quorum sensing, Ramachandran and Stevens hope to manipulate it in a way that is beneficial to society.
“Quorum sensing in this particular bacteria is really quite impressive,” said Ramachandran. “Bacteria are single celled, so this kind of communication and ability to coordinate with other bacteria is quite advanced.”
Ramachandran hopes that insight into quorum sensing in Pantoea stewartii will lead to the ability to prevent disease in other organisms, including humans, since many other species of bacteria also employ quorum sensing to regulate pathogenesis.
Ramachandran and Stevens have identified approximately 15 new genes that are directly regulated by quorum sensing in P. stewartii. “A gene can affect anything in the bacterium, from capsule production to motility and even bioluminescence,” said Ramachandran. “But to be able to test whether these targets affect pathogenesis brings us closer to the ultimate goal of identifying gene targets that can be used for disease intervention strategies.”
In her time at Virginia Tech, Ramachandran has worked as a teaching assistant in the department of biological sciences and served on a faculty search committee for that department. She’s presented her research at international conferences such as the 63rd Bacteria, Archaea and Phages Meeting, the 4th ASM Conference on Cell-Cell Communication in Bacteria and the Gordon Research Conference on Microbial Stress Response. She’s also published papers in the Journal of Bacteriology as well asApplied and Environmental Microbiology.
Her advisor and mentor, Ann Stevens, can testify to Revathy’s numerous accomplishments. “Using both proteomic and cutting edge Next-generation sequencing technology, Revathy has greatly expanded our knowledge of the genes controlled by quorum-sensing in P. stewartii,” Stevens said.
Previously, Ramachandran studied biotechnology at Visveswaraiya Technological University in Bangalore, India. “Coming to Virginia Tech to study microbiology was certainly a shift in focus for me, but one that has been very rewarding,” Ramachandran said.
Next, Ramachandran hopes to obtain a postdoctoral position where she can design experiments and continue researching. She aspires to one day develop a project and run her own lab at a prestigious university.
Written by Audra Norris, Communications Assistant, Fralin Life Science Institute
Q&A: Meet Revathy
B.S. Engineering from Visvesvaraya Technological University
What or who inspired you to be in this field of research?
My microbiology professor during my undergraduate degree greatly affected my love for microbiology. She was very enthusiastic and instilled in me a passion for bacterial research.
What do you enjoy the most in this research?
Surprisingly, it’s the trouble-shooting that I enjoy in research. Experiments don’t work out 90% of the time, which can be pretty frustrating. But I feel the most stimulated when I research for possible ways to get an experiment to work right, and it finally works.
What keeps you motivated to continue these corn plant virulence assays?
The corn plant virulence assays are a culmination of a few years of research, where we identified the genes controlled by quorum sensing in Pantoea stewartii. A gene can affect anything in the bacterium, from capsule production to motility. But to be able to test whether these targets affect pathogenesis brings us closer to the ultimate goal of identifying gene targets that can be used for disease intervention strategies.
What do you ultimately what to discover in the continuation of this research?
I would like to find out how dkgA and lrhA-- the two genes shown to be controlled by quorum sensing-- affect pathogenesis. Also interesting would be to see why the bacterium needs to regulate these two genes according to its cell density.
If you were to finish this research soon, what is the next big thing you want to research next?
Given the knowledge of quorum sensing that I have gained in these 5 years, I would like to study the communication between different bacterial species in an environment and see what factors play a role in that.
How do you recooperate from a failed or unexpected experiment, and how do you go about moving forward from that?
When an experiment fails, I resort to research. I look up similar experiments online, or email people who may have experience in a similar system. I often ask professors and other graduate students in our department if they have faced similar problems. If someone has already found a way out, I’d rather not spend time reinventing the wheel. If nothing works, then I resort to trial and error, which takes time but does eventually give results.