Go Microbe Hunting with Researcher Bill Bourland
I go microbe hunting with Bill Bourland on a warm, hazy day in August. We arrive at the deep-green, finely manicured lawns surrounding the Veterans Administration Medical Center in the Fort Boise area, where the retired doctor used to perform surgery. It’s a spot that most people would walk by and see nothing at all. But in his mind, Bourland can see microscopic creatures living underneath the bluegrass.
He bounces out of the car, lifts the tailgate and produces his weapon — a turkey baster with a bright red bulb on top, the same instrument your grandmother might have used to prepare the Thanksgiving turkey. He ambles up near a sprinkler head and pushes down with his sandal, and I hear the water-soaked sod go “squish.”
“Oh yeah, I think we can get some samples out of here,” he says. “It doesn’t have to be any kind of exotic special place. Once you start looking around, you start seeing these little mud puddles everywhere. It’s all there waiting to be found.”
Bourland sticks the turkey baster deep into the grass, squeezes the bulb and the clear plastic cylinder fills with a brownish clear liquid. “Got ’em!” He grabs a glass jar from the back compartment of the Subaru and squirts the liquid into the jar. He pushes his foot down again, inserts the baster and draws more liquid until the jar is three-quarters full. We can already see larger creatures swimming around inside.
This all reminds me of science class in elementary school, when we sampled water from a pond behind our school and put samples on slides to see what kind of single-celled organisms lived in the pond, species that we couldn’t see with the naked eye. That’s what we’re going to do at Bourland’s home in the foothills of Boise’s hip North End, where he has a basement laboratory.
In the center of a black countertop sits one of Bourland’s prized possessions, a research-quality Zeiss microscope. The microscope has a digital camera mounted on top connected to a Sony computer monitor. He places a drop of water from the glass jar on a clean specimen slide, drops a glass cover over the bead of water and loads it into the Zeiss microscope.
We see tiny round worms (nematodes) swimming around, and he zooms in closer, and we see the even smaller rotifers, which are multicellular organisms (metazoans). He zooms in some more, and we start to see ciliated protozoa swimming round. These are Bourland’s target species, each a complete animal in just a single cell. “Some ciliates are anchored to soil particles or bits of plants,” he says, “but I like to look at free-swimming mobile forms.”
We see a kidney-shaped ciliate called Colpoda, a relatively common terrestrial genus. Bourland zooms in on the creature. Our exploration of the cell’s anatomy begins on the blue computer screen as he points out the organism’s nucleus, then its tiny hairlike organelles that it uses for mobility, its opening in the outer membrane for ingesting food and another opening for discharging waste and more. All ciliate species possess tiny hairlike organelles known as cilia—hence, the name of this group of protozoa. The cilia look similar to flagella in other species, but the organelles are shorter and much more numerous, covering the outer membrane of the cell. Ciliated protozoa use the cilia for locomotion, whether it be swimming, crawling, attachment, feeding or sensation.
“This is how I go about looking at things,” Bourland says. “The simplest is the first step: get the specimen and see what’s in it. Then I begin studying it in more detail with different optical techniques and classify it. My interest is to find new organisms that have never been described before.”
The retired physician has had to learn a whole new vocabulary, so he can speak and write the language of specialists when publishing his findings in scientific journals.
SAMPLING BOISE, AND THE WORLD
Bourland is fascinated by ciliated protozoa — very sophisticated single-cell organisms that live in the water and the soil. Retired early after a 22-year career as a vascular and thoracic surgeon, Bourland spends his free time hunting for new species of ciliated protozoa in various mud puddles in the city of Boise. It’s not your typical hobby, certainly. But Bourland has had a lifelong interest in tiny organisms that can only be seen and understood through the lens of a high-powered microscope. For him, it’s a passion, a chance to discover new species that haven’t been found anywhere in the world, species that could help us understand more about how life evolves, spreads and organizes into complex communities.
So far, Bourland has discovered three unique terrestrial ciliates, Bryophrya gemmea, Etoschophrya inornata, and Agolohymena aspidocauda. He discovered a fourth, Bryophryoides ocellatus, not long ago, in a puddle on the well-irrigated green lawn behind the Boise Little Theater. He likes to draw samples from mud puddles next to Cartwright Road, various irrigation canals, several parks in Boise and farm ponds. He’s also collected samples from the desert flats where raptors like to catch mice in the Morley Nelson Snake River Birds of Prey National Conservation Area, south of Boise. When traveling the world with his wife, Debra, he’s collected samples in Finland, Brazil and Borneo.
On a website called “Micro*scope,” maintained by Arizona State University, Bourland has shared more than 1,700 digital images of about 650 species of ciliates since 2004. He’s met the world’s top ciliatologists and collaborates with them on a regular basis. Although he went through a lengthy amount of schooling and training to be a surgeon, he’s had to learn a whole new field of scientific discovery, a field called protistology, the study of protists — single-celled organisms, including unicellular algae and protozoa. He’s had to learn a whole new vocabulary, so he can speak and write the language of protistologists when publishing his findings in scientific journals.
It’s all there waiting to be found.
Bill Bourland, citizen scientist
FROM AFRICA TO ANN MORRISON PARK
Bourland is a “citizen scientist,” a category of intriguing people who have made huge scientific discoveries dating back to the 16th and 17th centuries. The first “microbe hunter” was Antonie van Leeuwenhoek, a Dutch carpenter who knew how to cut glass and invented the best microscope available in the mid-1600s.
With the microscope, Leeuwenhoek began documenting single-celled organisms. He identified various forms of bacteria, free-living and parasitic microscopic protists, sperm cells, blood cells, microscopic nematodes and more. In 1857, while working with yeast in Paris, microbiologist Louis Pasteur made the connection between airborne organisms and human disease. In doing so, he had to identify, classify and characterize many bacterial species in detail. He learned that some bacteria are good, even helpful to us human beings. And some bacteria are bad, causing infections such as tonsillitis, pneumonia and diarrhea.
Pasteur came up with the first vaccines for rabies and anthrax, and he’s well known for inventing pasteurization, a method for slowing the rate of spoilage for milk and wine.
Bourland is inspired by these early microbiologists, among many others, knowing how their discoveries have had such a profound impact on humans. One of his heroes is Alfred Kahl, a German high school teacher who began studying ciliates in mid-life, in the early 1900s. Kahl discovered 17 new ciliate families, 57 genera and about 700 previously unknown species. It was a time ripe for discovery.
Some bacteria are good, even helpful to us human beings. And some bacteria are bad, causing infections such as tonsillitis, pneumonia and diarrhea.
In Bourland’s mission to discover new species of ciliated protozoa, he found a ciliate, Puytoraciella dibryophryis, in a mud puddle in Ann Morrison Park, near the Boise River. This was a ciliate that he hadn’t seen before, so he began poring through the literature to determine its uniqueness. It turned out that P. dibryophryis had been discovered in the tropics of Africa. “It was the first time this particular species had been discovered in the Northern Hemisphere,” he says.
Bourland’s discovery showed that P. dibryophryis is more widespread than previously thought. How remarkable that the same species of ciliate found in the rainforests of Africa could be swimming around in a mud puddle in Boise’s Ann Morrison Park! Bourland smiles in the telling of his discovery.
So that’s one value of a microbe hunter searching for new species more than 300 years after the original microbe hunters began documenting them. It helps us understand the uniqueness and range of ciliated protozoa on a global scale. “It gives us an idea of how things evolved on Earth,” Bourland says. “How things are distributed — where they live, why they live where they live, how they contribute to the ecology of where they live.”
Terrestrial ciliates are “enormously important for maintaining soil health,” Bourland explains. “They transform nutrients in the soil, they eat bacteria and fungi, and control those things to some extent, and they provide food for other organisms, so they’re part of the microbial food web. In that way, they’re really important in uncultivated soils, agricultural soils and in aquatic environments.”
A UNIVERSE IN A DROP OF WATER
But what’s the deeper meaning? I ask Bourland. Why is it important to search for new ciliates? Why should anyone care?
“Because they’re so remarkable,” he says. “They are single-celled organisms, but they have all of the systems in place of much more complicated organisms. They have a way to encode their genetic information. They have a way to reproduce. They have a way to exchange genetic information sexually. They have a means of nourishing themselves — by different means. They can be carnivorous. They can eat bacteria and algae. They can absorb nutrients through their cell membrane and not eat anything at all. They have a way to move about. They have excretory systems for liquid and solid waste.”
1,700Digital images Bourland has shared of 650 species of ciliates on the Micro*scope website
“And they have systems for defending themselves from other predators,” he continues. “They have means of paralyzing their prey. So they are phenomenally complicated organisms, yet all of those systems are contained in one cell. From the standpoint of the organization of living things, they’re really remarkable. They have in one cell all of the division of labor that our bodies require with its billions of different cells.”
When he first inquired about adding images to the Micro*scope website, Bourland met David Patterson from the University of Sydney, Australia. He not only invited Bourland to contribute images, he visited him in Boise on several occasions. Bourland also met Wilhelm Foissner, the world’s preeminent ciliatologist, who teaches at the University of Salzburg, Austria. Their relationship started through an innocent email with a question. Bourland expected him to say, “Don’t bother me, you’re not one of us.” But actually, Foissner was immediately helpful.
“He was very gracious,” Bourland says. “He wrote a long e-mail back to me. He showed me how to be more detailed in my observations and what to look for.” Foissner even invited Bourland to visit Austria and see his lab, where he taught the citizen scientist more tricks of the trade.
“He’s probably the best in the world, so it was like studying at the feet of the master.”
Bourland isn’t worried about running out of things to do when it comes to discovering new ciliated protozoa and understanding how they tick. “There are literally thousands of ciliates yet to be discovered,” he says. “Some experts suggest that there are more to be discovered than have been discovered so far. It’s a matter of how hard people are looking for them or how carefully.”
About the book
Steve Stuebner is a longtime Idaho outdoors writer. This story is excerpted from “Idaho Microbes: How Tiny Single-Celled Organisms Can Harm, or Save, Our World” by Stuebner with Todd Shallat and was published last year by Boise State University School of Public Service. It’s available at Rediscovered Books in Downtown Boise, the Boise State Bookstore at the SUB, Boise State Publications website and Stuebner’s website.
Birth of a microscopic explorer
Bill Bourland was a curious kid growing up in Rockford, Ill. His grandfather, a physician, left behind an old brass German microscope. When 8-year-old Bill was poking around in his grandmother’s attic, he found it and took it home.
“In those days, all serious doctors had their own microscope. They had to do their own blood smears and lab work,” Bourland says. “My grandfather’s microscope was a very good microscope in its day.”
Bourland started using it immediately, looking at bacteria and blood smears — pricking his own finger for samples. “I set up my own microscopy lab with all kinds of materials — more materials than I probably should have been able to have as a kid. And later, I got interested in protozoa and water samples. I thought it was amazing that you could see so many different protozoa in a teaspoon of water. And there would be dozens, if not hundreds of types of protozoa in a small jelly jar.”
He remained interested in science through high school and earned a bachelor’s degree in zoology from the University of Iowa. He went to medical school at the University of Iowa and completed his residency in general surgery at the University of Washington. He launched his surgery practice in Boise in 1986 and practiced medicine until 2008, when he started his work as a citizen scientist.
One day, Bourland got a wild hair and bought his first microscope, a Leica. When he upgraded and added a feature called differential interference contrast, he could see the one-celled creatures in three-dimensional relief. That made it easier to identify different features of ciliated protozoa, apply stains to the specimens and take digital photos of the species.
“That really opened up a whole new world to me,” he says, grinning. “It’s like an astronomer getting a Hubble telescope. It’s completely captivating. You could sit there for hours looking at one drop of water.”