Charlie Culbertson sits in S. Fernald’s Country Store in Damariscotta on March 3. Culbertson, of Alna, is a retired microbial ecologist who discovered different types of microscopic organisms that were theorized to have existed billions of years ago when life first started. Culbertson worked for the United States Geological Survey for 21 years. (Alec Welsh photo)
While pushing the boundaries of human knowledge, Alna resident and microbial ecologist Charlie Culbertson learned firsthand major discoveries can sometimes seem to suddenly appear, even when they are not being looked for.
“It actually happens quite a lot,” Culbertson said.
Completing his bachelor’s degree in microbiology at San Francisco State University in 1978, Culbertson went on to pursue a master’s degree in microbial ecology. In 1981, Culbertson was studying nitrogen cycling in the San Francisco Bay when he accidently discovered a bacterium that could use the chemical acetylene as an energy source without needing oxygen to survive, something scientists had believed to be possible for decades, but had never actually documented.
“Scientists have theorized about this since the early 1900s,” Culbertson said.
The discovery of the bacterium led to an entirely new field of research called acetylenotrophy, which studies how this bacterium breaks down the gas acetylene as a food source.
According to Culbertson, scientists had theorized the existence of these bacteria based on the theoretical environment of Earth 3.5 billion years ago, when life is thought to have started. Because acetylene was abundant in Earth’s atmosphere when life had originated, it was thought some organic organism had to be able to consume the gas as a food source. Culbertson’s discovery confirmed the prediction.
After publishing an article detailing the discovery in the Origins of Life and Evolution of the Biosphere magazine in 1988, Culbertson’s work was recognized by renowned scientist Carl Sagan.
“Dude, that paper is still being cited today.” Culbertson said. “One of the reviewers of our work said ‘this needs to be published immediately’ and it was Carl Sagan.”
The discovery not only helps scientists gain knowledge about the origins of life on Earth, it allows scientists to look at other planets within the solar system that might contain the conditions for the life forms to grow.
Culbertson’s paper, published in 1988, argued the existence of acetylene in the atmospheres of Jupiter, Saturn, and in Saturn’s largest moon, Titan, means life forms similar to the bacterium Culbertson discovered could exist elsewhere in the solar system.
Later in his career Culbertson would continue to push the boundaries by searching out extreme environments in hopes of finding microscopic life forms that might have existed billions of years ago. According to Culbertson, extreme environments on earth today are similar to the typical environment on earth when life had started.
Working with his former mentor, Ron Oremland, as part of the United States Geological Survey, Culbertson’s pursuit of the extreme environments led him to Mono Lake in California.
“I was still part of Ron’s team in San Francisco and we were looking for ancient enzymes that we believed use to exist when life started on earth,” Culbertson said.
What made the lake an extreme environment according to Culbertson was the high salt content and the high pH level of the water caused by its proximity to a volcano.
“It was an obvious place to find weird life,” Culbertson said.
While studying the lake, Culbertson and his team found exactly what they were looking for – a bacterium that could consume arsenic through photosynthesis and without the presence of oxygen. Arsenic is toxic to humans,
The discovery was reported in The New York Times in 2008 and published in Science, a scientific journal founded in 1880.
“It is the ultimate publication,” Culbertson said. “To get a paper in Science, it had to be significant.”
Culbertson’s discovery of arsenic consuming bacteria was not the only one he made at Mono Lake. The lake was also home to a new type of algae Culbertson’s team nicked named Mickey, due to the algae’s resemblance to the Disney character Mickey Mouse.
“It had a nose and two ears so we nicknamed it Mickey,” he said. “It was bizarre, nobody had seen it before.”
After discovering the algae under a microscope in early 1980, Culbertson and his colleagues spent days investigating different types of pollen around the lake in what was ultimately a futile attempt to identity the new algae. The team had believed because of the algae’s geometrical shape it was more likely to be pollen.
After shining a florescent light on the algae they realized it couldn’t be pollen.
“The ears started to glow because of the presence of chlorophyll, which pollen doesn’t have,” Culbertson said.
Culbertson moved to Maine in 1999 as a compromise with his wife, Collin Roesler, who lived in Connecticut while he lived in California. The couple moved after Roesler, an oceanographer, was hired to work at Bigelow Laboratory for Ocean Sciences in Boothbay.
“It was neutral territory,” Culbertson said of his move to Maine.
Since moving to Maine Culbertson retired from the United States Geological Survey but has worked as an emeritus scientist for the department, studying toxic algae blooms known as cyanobacteria. The algae, also known as blue-green algae have been thriving in Maine lakes and poses significant environmental hazard, according to Culbertson.
“These fresh water algae blooms is, going forward as we continue to warm, one of the major environmental challenges that not just the U.S., the planet is going to have,” he said.
As part of the emeritus program Culbertson works essentially as a volunteer. He is provided resources from the United States Geological Survey, but does not receive a salary.
“The program is for geeks like me that love science and want to keep working,” Culbertson said.
For the past two years Culbertson has been serving on the Alna Select Board, winning election in 2021. He said he was motivated to run for the board on the belief he could bring the community together.
During his time with the board Culbertson helped residents obtain financial aid through the town’s general assistance program. Despite not seeking reelection to the select board, Culbertson said he plans to continue managing the program so an incoming select board member does not have to learn how to run the program on the fly.
“I feel like we have built such good momentum with the program and want to make sure there are no setbacks,” Culbertson said.
Culbertson said the program is incredibly important for residents living paycheck to paycheck.
“Some people really need it even if it is just $100,” he said.
Culbertson decided against running for a second term this year to spend more time with his 18-year-old son, Jack, before Jack goes to college this fall. When Culbertson is not chasing the origins of life or serving his community, he is likely playing baseball or coaching the next generation of ball players.
Culbertson said he has been coaching baseball since he lived in California.
“I have coached for years, and years and years,” he said.
Coaching Little League baseball wasn’t enough for Culbertson who started playing in the Maine Woods Baseball League in 2017. Culbertson played in the league until last year when he tore his rotator cuff pitching to Little Leaguers.
Undeterred by his injuries Culbertson says he plans on being back on the field after he is healthy.
“I have loved the sports since before Little League,” Culbertson said. “Once I am healthy, I will be back on the field.”
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