Montana scientist's interest springs from Yellowstone Park studies
George Schaible's interest in bacteria began while studying microbes in Yellowstone National Park.
Now backed by a prestigious NASA grant, Schaible, a Montana State University graduate student, will investigate bacteria that could provide insights into how multicellular life evolved.
Schaible, a doctoral student in the Department of Chemistry and Biochemistry and a fellow in MSU's Molecular Biosciences Program, was one of only 34 graduate students in the U.S. to receive the Future Investigators in NASA Earth and Space Science and Technology award, or FINESST, from the space agency’s Planetary Science Division.
The $133,000 funding will support three years of Schaible exploring multicellular magnetotactic bacteria, the only known kind of bacteria to be composed of multiple cells throughout its entire life cycle.
"These bacteria are potentially a very good model to understand the evolution of multicellular organisms on early Earth," said Schaible, whose adviser is Roland Hatzenpichler, assistant professor in the Department of Chemistry and Biochemistry in MSU's College of Letters and Science. "Learning more about them could fundamentally transform how we interpret the potential for complex life elsewhere in the universe, as well as how we think about bacteria — whether they're really as simple as is often assumed."
Although many kinds of bacteria can form biofilms composed of many cells, and a handful of bacteria have been observed in lab settings to grow into multi-celled forms, the vast majority are single-celled. In addition to being the lone example of exclusively multicellular bacteria, the organisms Schaible studies have a remarkable ability to navigate to preferred habitat by sensing Earth's magnetic field and swimming through water.
"It's almost like birds migrating," Schaible said. "They're basically forming compass needles inside their cells." In the Massachusetts salt marshes where he studies the microorganisms, they swim upward or downward through water-filled pores in sediment until reaching an area with the right amount of dissolved oxygen.
GOING IN VITRO
Although scientists have known about the bacteria for more than two decades, they haven't been able to grow, or "culture," them in a laboratory setting, which has stymied efforts to understand how the microbes achieve their unique form. That's where Schaible's research comes in.
"It's a tremendous opportunity for him and for our lab," Hatzenpichler said of Schaible's NASA-supported project. "We think these bacteria might hold clues to what makes life go from single-celled to more complex forms."
Since starting his doctoral studies at MSU in 2018, Schaible has combined new methods of treating the magnetotactic bacteria in Hatzenpichler's lab with advanced, high-resolution microscopy tools to develop new ways of examining their cellular structure, with the hope of finding out what the bacteria need to be cultured.
"This was simply not possible before," Hatzenpichler said of Schaible's new methods. "It took a lot of effort on his part. That's one thing I really like about working with him — his initiative."
Being able to culture the unique microbes would open the door to more controlled experiments, which would be a major breakthrough because researchers could easily study the bacteria through their whole life cycle, Hatzenpichler said. "It could really jump-start a whole new research front."
Schaible, who is from Missoula, earned his bachelor's in biotechnology with a microbial focus from MSU in 2014. He also earned minors in biochemistry and astrobiology, which involves studying how life originated to understand what it might look like elsewhere in the universe, and co-authored three scientific papers while conducting research with faculty, including professor of microbial ecology Dave Ward.
While working in Ward’s lab, Schaible studied bacteria that form mats and photosynthesize like plants in a backcountry hot spring in Yellowstone. By sequencing the genes found in the bacterial mat, the researchers could see that it was actually composed of several strains of the same species of co-habitating microbes.
"One of my favorite things about being an undergraduate at MSU was that we were encouraged to join research labs," Schaible said. "Those experiences really got me into research and how interesting and exciting it can be."
Like the magnetotactic bacteria, certain strains of the Yellowstone microbes Schaible studied have yet to be cultured, making them what scientists sometimes refer to as microbial “dark matter.” Just as the elusive particles hunted by physicists may account for much of the theoretical density of the universe, uncultured microbes are thought to account for upward of 98% of all microorganisms — an untapped scientific storehouse of nature's microscopic variety.
It was Schaible's interest in microbial dark matter, sparked by his undergraduate research experiences, that led him — partly by happenstance — to Hatzenpichler's lab. After teaching English in China for a year, Schaible was living in Los Angeles and attended a presentation on the subject at the California Institute of Technology. There he met Hatzenpichler, who was then a postdoctoral researcher soon to depart to MSU for a faculty position. The two hit it off and kept in touch as Schaible returned to Montana and applied to graduate schools.
"To be successful in astrobiology, you need to think very broadly and be open to collaborating with other people whose ideas are far outside your expertise, and George is well suited for that," Hatzenpichler said.
Upon returning to MSU, Schaible was named a Molecular Biosciences Fellow, which allowed him flexibility to conduct research across departments, including in the Department of Chemical and Biological Engineering in MSU's Norm Asbjornson College of Engineering. He was also awarded a STEM Storytellers Fellowship, funded by the National Science Foundation to improve graduate students' oral communication skills. And with one of his fellow lab members, Anthony Kohtz, Schaible founded MSU's Astrobiology Journal Club, which meets weekly to discuss the origins and evolution of life and its potential distribution in the universe; the club is open to both undergraduates and graduate students from all disciplines.
"Those are questions that fascinate me," Schaible said. "How did life start? And what would it look like to find it somewhere else in the universe?"