Sept. 19, 2018
Danny Ducat, an assistant professor in the Department of Biochemistry and Molecular Biology, works with one of the oldest species on Earth: cyanobacteria. By tweaking their DNA, Ducat forces the bacteria to release sugars that can be used in the manufacturing of plastics that will degrade naturally.
Growing up on a steady diet of fantasy and sci-fi novels, I've been attracted to the idea of the unusual and alien for as long as I can remember. So imagine my delight when I first started to pick up books on microbiology and cell biology.
A multitude of tiny worlds were described that are all around us and are populated by living organisms with seemingly little resemblance to anything found in our normal daily lives. Yet, unlike the other books I was reading, these worlds were real.
Well, I was immediately hooked and, in retrospect it seems like only a blink of time before I was enrolled as an undergraduate at Michigan State majoring in microbiology and molecular genetics.
Beyond my fascination with the microcosm of bacterial worlds, I was also very interested in the natural environment around me that I could see and touch. Growing up on a tree nursery, being an avid Scout and being a product of a generation with programming that included David Attenborough and Captain Planet, all gave me an appreciation for nature and a desire to work towards preserving it against some of the negative consequences of our modern lifestyles.
I increasingly began to look for ways to bring my two interests together — to apply my training in microbiology towards environmentally relevant pursuits.
This is when I first began to study cyanobacteria. These tiny microbes are closely related to some of the oldest organisms on the planet, but contain similar molecular machinery to modern plants. Consequently, they are capable of absorbing sunlight and using the potential energy contained therein to catalyze reactions that turn carbon dioxide into useful cellular components for growth and reproduction.
But because cyanobacteria are relatively simple, they are also easy to examine, and to manipulate. So it is possible to reprogram cyanobacteria to divert some of the energy they capture from sunlight into compounds that are useful for humans too.
As it turned out, there was rising interest in the use of cyanobacteria for environmentally sustainable technologies. At the same time, a new discipline of biological engineering was emerging called synthetic biology. I was fortunate enough to be able to begin using some of these cutting-edge tools and approaches to examine cyanobacteria — with a primary goal of modifying them so that they could produce sustainable products, like biofuels.
Cyanobacteria hold tremendous potential if they can be appropriately harnessed: They naturally have high photosynthetic efficiencies, and they don’t require the use of arable land or potable water to grow like plants do. But cyanobacteria and algae also have a steep uphill battle — we’ve only been trying to farm these organisms for a couple decades, whereas we’ve been farming plants literally since the cradle of civilization.
Our technology, tools and infrastructure for mass cultivation of cyanobacteria lag far behind, which makes the economics of growing these simple microbes surprisingly complex.
My lab currently studies cyanobacterial biology and biotechnology with two primary goals. We want to innovate new approaches that enable cyanobacteria to be more feasible for real-world biotechnology applications, and we also often aim to investigate fundamental properties of their cell biology that have bearing on their efficiency to convert solar energy or the capacity to farm them on a large scale.
We are currently engineering communities of microbes, where the cyanobacteria harness solar energy to feed other co-cultivated microbes that produce useful products. These co-cultivated microbes can convert the sugar into higher value compounds (e.g., bioplastics, biofuels) in the same “pot,” which would eliminate the need to harvest the sugar.
Our vision is that if we can better understand how microbial interactions emerge between species, we can use synthetic biology principles to build “plug-and-play” communities to efficiently create a variety of bioproducts from sunlight and CO2.
Because the communities we build are relatively simple, we have more refined tools to investigate them and a larger capacity to control their function, pushing them to be better and more productive.
