New Science Tracks Microbes in Smoke at University of Idaho

Leda Kobziar didn’t expect her ecological studies to launch into the troposphere. The University of Idaho fires science professor hadn’t considered that publishing a paper on the spread of microbes in wildfire smoke would be a game changer in fire science circles.

Over the past couple of years however, Kobziar’s name has become synonymous with a new field of ecological research called pyroaerobiology. It is a name she coined to describe the study of living microorganisms found in plumes of forest fire smoke. Her work has appeared in national and international media and been published in several journals.

“The interest the smoke research has garnered has been crazy,” Kobziar said.

In collaboration with scientists at the University of Florida and Colorado School of Mines, Kobziar’s U of I team, which includes undergraduate, graduate and postdoctoral students, explores the ecological and pathological repercussions of airborne bacteria and fungi hurled into the atmosphere during wildfires. Her group found more than a thousand different organisms surfing the smoke waves.

The next step, said Kobziar, is to determine how long microorganisms can live in the smoke, how far they can travel, and what effects they can have on natural systems.

“Are there repercussions for aquatic ecosystems from smoke transported over water bodies?” Kobziar asked. “Does smoke transport pathogenic organisms that can affect humans and crops, or is it transporting beneficial organisms critical for soil functioning?”

Early Research

The idea that smoke could be a source of living microbes was first investigated almost 20 years ago, when a Texas father-daughter team, Forrest and Sarah Mims, published a paper in Atmospheric Environment that showed viable fungal spores were present in smoke from distant wildfires.

The Mimses sampled air using a kite flown over the Gulf Coast. They found bacteria and fungi in smoke from forest fires in Yucatán, Mexico.

The Mims’ findings were not well publicized, and most scientists assumed smoke was too hot, gaseous and toxic to sustain living organisms — until Kobziar and her team showed, once again, microbes can be transported in the baking, volatile smoke of burning forests and grasslands.

Because pyroaerobiology is so new, Kobziar’s team is constantly developing novel ways to collect microbes from smoke. Phinehas Lampman, a doctoral student, drone pilot and former firefighter who grew up in Headquarters, Idaho, modifies drones using aluminum bar stock to attach small pumps and tubes. The mechanisms suck wildfire smoke through filters where the airborne fungi and bacteria can be collected.

“There aren’t any established ways to do any of this,” Lampman said. “We’re always coming up with new or better methods to conduct experiments, and that’s what makes it so interesting.”

So far, Kobziar and colleagues discovered that over 80% of the microbes in smoke samples collected from burning forests in Florida were alive. Additional samples collected with drones from extremely intense fires in the Rocky Mountain West found 60% of microbes had survived the intense heat of the smokey highway.

She estimates that 40 trillion to more than 100 trillion microbes are released into the atmosphere for every 2.5 acres burned in low- to mid-intensity fires.

“This means that larger fires would be predicted to mobilize even larger numbers of microbes,” Kobziar said.

Researchers found that microbes globbed onto airborne particles of burned plant or soil material. They learned microbes in the atmosphere enhanced condensation and freezing of water. By acting as ice-nucleating particles, the clumps of microbes can influence precipitation and change weather.

New Frontiers in Smoke Science

Hannah Griffin, who attends North Idaho College with plans to pursue a medical career, said joining Kobziar’s crew via an INBRE (IDeA Network of Biomedical Research) scholarship has given her an out-of-the-box view of microbiology.

Griffin is exploring whether microbes found in smoke have higher heat and drying tolerance than microbes found in non-smoky air.

“The hypothesis is that microbes found in smoke are more tolerant of high temperatures and drying,” Griffin said. “How smoke and heat can affect adaptations in microbes is something I had not considered before working with this team.”

Earth scorched by recent fires may seem like a wasteland because the microbes critical to plant health and nitrogen processing are severely reduced. But the new science shows that smoke can relocate bacteria and fungi to barren areas, essentially “reseeding” those places with new microbes.

The process of smoke-borne microbes adapting and being relocated has likely been happening for hundreds of millions of years, Kobziar said.

“Fire has been influencing the world in this way, as a microbial volcano,” she said. “This changes how we think about fire’s role on earth, and its effect on atmospheric processes.”

She and her fellow researchers theorize that smoke may be a temporary refuge for microbiota.

“These are the things that our upcoming work is going to try to unravel and test,” she said. “There seem to be an infinite number of questions that remain to be answered.”

Article by Ralph Bartholdt, University Communications.

Photos and video by Melissa Hartley, Visual Productions.

Video editing by Garrett Britton, Visual Productions.

Published in September 2022.