Fifty miles off the sun-drenched Tuscan coast, amidst a sparkling blue expanse dotted with rugged, remote islets like the fabled Island of Montecristo, an ancient form of life thrives. These tiny creatures spend their days feasting on an unexpected meal: methane, a potent greenhouse gas that constantly seeps from cracks in the seafloor.
Recently, researchers have embarked on an ambitious quest to enlist these microorganisms in a vital mission. They aim to understand if the microbes’ natural appetite for methane can be redirected to tackle the vast quantities of this planet-warming gas released annually from sources like oil and gas operations, livestock, and wetlands. Success could offer a groundbreaking strategy to slow down climate change.
However, before these microbial allies can be truly understood and deployed, scientists must first unravel the mysteries surrounding them. These organisms have inhabited Earth for billions of years, yet much about their existence remains largely unknown. A series of captivating visuals showcases the scientific journey: from sailing under the predawn sky to locate underwater mud volcanoes, to the specialized tools used in the expedition, and moments of rest for the dedicated team, including Captain Roberto Scotto guiding their vessel.
One such habitat favored by these microbes is the ocean floor, where methane, long trapped deep within the Earth, escapes through seabed fissures. In 2017, local fishers reported a dramatic 30-foot jet of murky water erupting near Montecristo. Geologists later identified this as a chain of offshore mud volcanoes, tirelessly releasing methane into the pristine blue waters. Yet, until recently, no one had attempted to study the organisms responsible for consuming this gas in such a unique environment.
Life in Unlivable Places
While most atmospheric methane originates from microbes decomposing organic matter in swamps, landfills, and animal digestive systems, a distinct group of microorganisms actively devours methane. Only in recent decades have scientists begun to grasp the intricate processes enabling them to achieve this feat.
Methane, a primary component of natural gas, is a surprisingly challenging energy source for any organism. Its chemical structure demands complex metabolic maneuvers and a significant energy expenditure from microbes to utilize it. Nevertheless, once scientists identified and decoded these methane-eating bacteria, known as methanotrophs, they discovered them virtually everywhere: in rivers, soils, deep-sea vents, and even tree bark. In certain environments, these bacteria consume methane before it ever has a chance to reach our atmosphere.
The collective impact of these methanotrophs is immense. Globally, these minuscule organisms consume many times the amount of methane that humans release into the atmosphere. This implies that without their tireless work, our planet would likely be significantly warmer today. This revelation fuels the hope that if these microbes can be spurred to work even harder, they could become powerful allies in the fight against climate change, much like other microorganisms used in medicine, pest control, and wastewater treatment. A striking colorized image of methanotrophs seen through an electron microscope, a view of a small undersea mud volcano, and gas bubbles naturally rising to the surface illustrate the microscopic world and its profound potential.
Despite their immense potential, harnessing methane-eating bacteria has proven to be a complex challenge. Some perish with even the slightest exposure to oxygen, while many operate in intricate symbiotic relationships with other organisms. “They’re dependent on each other and almost certainly other factors, and we just don’t know exactly what they need,” explains Jeffrey Marlow, an assistant professor of biology at Boston University.
This complexity is precisely why Dr. Henriksen, Dr. Tierney, and genomic scientist Krista Ryon are venturing into Earth’s most extreme environments. Their goal is to discover if microbes in these unique locations possess novel characteristics – or perhaps are simply strange enough – to help mitigate the environmental damage caused by fossil fuel use and industrial agriculture. The three scientists, along with their collaborators, have collected samples from diverse locations, including hot springs in Colorado and volcanic seeps off the coasts of Sicily, Japan, and Papua New Guinea. Their globe-trotting research is facilitated by the Two Frontiers Project, a nonprofit organization supported by various donors, including Seed Health, a probiotic manufacturer.
In Search of Purple Blobs
On a cool summer night aboard their dive boat, Dr. Tierney, Ms. Ryon, and Gabriele Turco, a marine ecologist from the University of Palermo, were filled with eager anticipation as they awaited daybreak. After a midnight departure and a four-hour westward journey, they dropped anchor, peering out over the dark waters. A flick of a spotlight revealed beads of gas lazily bubbling up from the depths – a promising sign of a methane seep.
This particular corner of the Mediterranean remains largely unexplored territory for biologists, as Dr. Turco, who also works for Italy’s National Biodiversity Future Center, noted: “We have studied just a few parts of the tip of the iceberg.”
Following sunrise, the scientists donned their scuba gear and submerged into the water. Below them, a vast, gently sloping saucer of sand and sediment formed the distinct dome of a mud volcano. Starting at its base, roughly 50 feet deep, they carefully collected samples of seawater, sediment, and microbial biomass – gooey assemblages that could be charitably described as resembling mucus.
Dr. Tierney’s keen eye spotted a fuzzy, chewing-gum-sized wad of purple biomass clinging to an algae-furred boulder. He excitedly secured it in a sample bag. Moments later, Dr. Turco discovered a miniature mud volcano nestled on the flank of the larger one. Dr. Tierney uncapped a sample tube, corkscrewed it into the sand, and watched as three plump bubbles erupted. The small mound jiggled like flan when touched, a clear indication of its gas saturation and likely abundance of microbial life.
In total, the researchers collected 22 samples from the large volcano, carefully transferring them to a cooler on their boat. The following morning, they ventured near the island of Elba, where they explored swaying sea grass meadows and the imposing wreck of the Elviscot, a cargo ship that sank in 1972. To Dr. Tierney’s delight, another purple blob was found, suggesting a chemical similarity between the two sites despite a 25-mile separation. The visuals from this part of the expedition capture the stunning real-life Island of Montecristo, and show Ms. Ryon and Dr. Tierney preparing for a dive, then meticulously collecting samples on the seafloor alongside Dr. Turco.
The team amassed 43 samples, which they quickly transported back to their Airbnb for preliminary processing. Their makeshift lab was quite basic: samples were stored in the kitchen refrigerator, nestled alongside eggs and half-eaten croissants. To maintain sterility during processing, windows were sealed and the air-conditioning switched off, turning the cramped bedroom into a humid sauna. Dr. Tierney showcased one of the purple blobs – a clumpy mixture, he surmised, of bacteria and other organic matter resembling pond slime or spoiled food, possibly intermingled with algae. “Let’s make sure we get as much of the actual goop as possible,” he emphasized. Once securely transferred to new vials filled with various nutrient broths to ascertain the bacteria’s environmental preferences, these tiny specimens were shipped via FedEx to Dr. Henriksen’s lab in Colorado, where they are now being cultivated with methane.
Nature’s Surprises
Currently, the most straightforward methods to reduce atmospheric methane levels don’t involve bacteria at all. Instead, they focus on preventing methane release in the first place, through actions like repairing pipeline leaks, diverting organic waste from landfills, and modifying livestock diets. However, these simpler, low-tech solutions are not yet being adopted widely enough to significantly curb emissions. This is where scientists hope microbes can offer a crucial helping hand.
Dr. Lidstrom and her team at the University of Washington are developing a device designed to remove methane by pumping air from above emission sites through a tank containing a microbial ‘soup.’ The significant hurdle, she notes, is scaling this technology to atmospheric levels. Moving such vast quantities of air would demand enormous energy, and if that energy generation relies on burning fossil fuels, it would partially negate the climate benefits. Meanwhile, Windfall Bio, a California-based startup, utilizes methanotrophs to convert excess methane into valuable products like fertilizer. The company has already conducted small-scale trials of its technology at a landfill and a dairy farm.
Josh Silverman, Windfall’s co-founder and chief executive, points out that a major challenge in employing microbes for climate solutions lies in funding. “People are not willing to pay for sustainability, and they’re not willing to pay for climate,” Dr. Silverman said. “So while it’s good to be aligned with that, that can’t be the only thing that drives it.” He and his colleagues are exploring novel ideas, such as coating cardboard boxes with microbes. These bacteria would then consume ambient methane as the boxes are transported globally, and if the boxes are later composted, the microbes could continue their methane-eating work within the compost pile. “There’s a whole lot of surface area of cardboard boxes,” Dr. Silverman enthusiastically adds.
The Two Frontiers team is diligently analyzing the specimens collected this summer in Italy. Initial findings are promising: their samples include a symbiotic blend of algae and bacteria that appears to thrive on a combination of sunlight and methane. This microbial partnership could prove invaluable for methane capture in environments like rice fields, a significant source of emissions. For their next venture, Two Frontiers plans to investigate drier areas featuring terrestrial mud volcanoes. Dr. Marlow of Boston University is also keen to explore the seafloor off Angola and Namibia, regions that still hold many secrets – and, he anticipates, new species of methanotrophs. Dr. Marlow initially dreamed of working on Mars missions, drawn to extreme environment microbes for their potential to shed light on extraterrestrial life. Now, he reflects, “it’s clear that they matter a lot on Earth, too.”
A final video showcases a lighthouse perched majestically on a cliff, with subtle bubbles rising from the ocean below, symbolizing the ongoing natural processes and the hope for a cleaner future.