This post is written by UT Austin undergrad researchers Katelyn Corley, Matthew Hooper, and Zachary Martinez
“What starts here changes the world.” This is the motto that we as students at the University of Texas at Austin have come to embrace and strive towards in our everyday lives. In 2016, we began conducting research at UT Austin. For most of us, this was the first time we conducted research. We also took part in iGEM (international genetically engineered machine), and attended the annual conference in Boston. Our research experiences broadly spanned topics including microbiology, molecular biology, and synthetic biology, but our main work in 2016 focused on studying the microbiome of kombucha, with an ultimate goal of creating a designer beverage by altering the kombucha microbial community.
Example of kombucha “brewed” in a test tube. The large mass at the top is a layer of cellulose, while the mass at the bottom and the stringy “material” throughout the tube are clumps of bacterial and yeast cells.
Kombucha is a popular fermented tea beverage that is home to a variety of microbes, both bacteria and yeast. Many die-hard consumers of kombucha love its acidic qualities and its characteristic vinegar taste, while these same attributes are what often turn others away from the drink. More importantly, kombucha is commonly referred to by its producers as being healthy or “rejuvenating” due to the presence of probiotics that are said to aid in digestion. As undergraduate scientists, we are skeptical of these claims, particularly because no current scientific evidence supports them. To us, kombucha soon became a vast frontier full of gray areas and large unknowns. Is it healthy, and if so, what makes it healthy? If not, could we make it healthy? These questions are what continually drove us forward as both researchers and as members of a community who desire to put something good into the world.
So then what did we learn? Over the course of roughly 6 months, the three of us along with our team, studied the “mysteries of kombucha”. We first identified some of the microbes that are naturally found in the drink. Species of bacteria such as Gluconobacter oxydans and Gluconacetobacter hansenii became commonplace names in our lab as we characterized these organisms and attempted to genetically engineer them for future study. Another major contributor to kombucha that we identified was the yeast, Lachancea fermentati. Interestingly, we found two unique strains of this species in our samples of kombucha with different phenotypes, and both appear to be required for proper kombucha brewing. One grew more quickly, while the other produced higher amounts of CO2. This finding immediately intrigued us. Not only do an array of species of bacteria and yeast coexist in kombucha, but differences in members of the same species appeared to have evolved in the process! Differentiation in the species was a possibility that we had not considered at first. The community of organisms that exists within kombucha appears to have evolved in a way that was much more complex than we had initially imagined. Kombucha was not simply a tea drink that was commercially sold and consumed, but was an exciting example of the world of microbial communities, which possess aspects of evolution and symbiosis that are still not fully understood.
Members of the Austin UTexas 2016 iGEM Team (from left to right): Prachi Shah, Matthew Hooper, Zachary Martinez, Katelyn Corley, Stratton Georgoulis, Alex Alario, Ian Overman
We had the privilege of presenting our research at the 2016 iGEM “Giant Jamboree” in Boston. This research competition is one of the most incredible opportunities offered to both undergraduate and post-graduate students in the field of synthetic biology. We spoke with other students who work in our field and shared many of our successes and difficulties along the way. Additionally, we had the chance to present our research on kombucha to scientists, who gave us feedback and additional suggestions for expanding our project in the future. Our future plans include studying how the microbial community changes during a single brewing cycle as well as how the community might collectively evolve over multiple brewing cycles.
The major take-away from this experience was that, there is still work to be done, but that it is important work. Many of us first saw this project as being fun and approachable, and though we still view our lab work in this way, we have now begun to see how the scope of this project extends into greater, more compelling fields of science. Kombucha offers immense outlets for exploring the limitations of synthetic biology, as well as in exploring the types of evolutionary changes that must occur to enable specialization and the coexistence of microbes. Additionally, if we were to create a “designer” kombucha beverage, we need to consider the potential evolutionary shifts that might occur as we alter the microbial community found within kombucha. The great part about science is that you never know where it will lead you. This project took us from a grocery store shelf holding a bottle of kombucha, to an international conference in Boston, to a situation where we are now beginning to see how our work could shed light on an area of science that is not fully understood. On behalf of the entire Austin UTexas iGEM team, we encourage others to never stop digging deeper into science.
