Scientists Create Aircraft Fuel from Soil Bacteria

An airplane prepares to land at Cointrin airport in Geneva,
Switzerland December 5, 2017. REUTERS/Pierre Albouy
An airplane prepares to land at Cointrin airport in Geneva, Switzerland December 5, 2017. REUTERS/Pierre Albouy
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Scientists Create Aircraft Fuel from Soil Bacteria

An airplane prepares to land at Cointrin airport in Geneva,
Switzerland December 5, 2017. REUTERS/Pierre Albouy
An airplane prepares to land at Cointrin airport in Geneva, Switzerland December 5, 2017. REUTERS/Pierre Albouy

Aircrafts transport people, ship goods, and perform military operations, but the petroleum-based fuels that power them are in short supply. In research published on June 30 in the journal Joule, researchers at the Lawrence Berkeley Lab have found a way to generate an alternative jet fuel by harvesting an unusual carbon molecule produced by the metabolic process of bacteria commonly found in soil.

"In chemistry, everything that requires energy to make will release energy when it's broken. When petroleum jet fuel is ignited, it releases a tremendous amount of energy, and the scientists at the Keasling Lab at the Lawrence Berkeley Laboratory thought there must be a way to replicate this without waiting millions of years for new fossil fuels to form,” said lead author Pablo Cruz-Morales, a microbiologist at DTU Biosustain, part of the Technical University of Denmark.

The idea was born years ago, when Jay Keasling, a chemical engineer at University of California, Berkeley, approached Cruz-Morales, who was a postdoc in his lab at the time, to see if he could synthesize a tricky molecule that has the potential to produce a lot of energy. "Keasling told me: it's going to be an explosive idea," according to Cruz-Morales. The molecule that Keasling wanted to recreate was called Jawsamycin, created by the common bacteria streptomyces, an organism that Cruz-Morales had worked with in the past.

"The recipe already exists in nature," says Cruz-Morales. The jagged molecule is produced by native metabolism of the bacteria as they munch away on glucose. "As they eat sugar or amino acids, they break them down and convert them into building blocks for carbon-to-carbon bonds," he said.

"You make fat in your body in the same way, with the same chemistry, but this bacterial process has some very interesting twists. These twists, which give the molecules their explosive properties, are the incorporation of cyclopropane rings -rings of three carbon atoms arranged in a triangular shape," he added. After careful analysis, the team determined that the enzymes that were responsible for the construction of these high-energy cyclopropane molecules were polyketide synthases.

"Polyketide synthases are the ultimate biological tool to make organic chemistry," says Cruz-Morales.

Cruz-Morales explains that the fuel produced by the bacteria would work a lot like biodiesel. It would need to be treated so that it could ignite at a lower temperature than the temperature needed to burn a fatty acid, but when ignited, it would be powerful enough to send a rocket into space.

"If we can make this fuel with biology there's no excuses to make it with oil. It opens the possibility of making it sustainable," says Cruz-Morales.

In the future, Cruz-Morales hopes that he and the team of Department of Energy researchers who worked on the project will be able to scale up this process so that their alternative fuel could actually be used in aircrafts.

"You can see this as a preparation for the moment because we are going to run out of fossil fuels, and there's going to be a point, not far from now, when we will need alternative solutions," Cruz-Morales explained.



There Are Fewer Than 100 Ocelots in the US - These Scientists Are Trying to Save Them 

Zookeeper Laura Carpenter of the Cincinnati Zoo observes 5-year-old female ocelot Milla after the wild cat underwent an in vitro fertilization procedure at the Texas State Aquarium in Corpus Christi, Texas, US, December 9, 2024. (Reuters)
Zookeeper Laura Carpenter of the Cincinnati Zoo observes 5-year-old female ocelot Milla after the wild cat underwent an in vitro fertilization procedure at the Texas State Aquarium in Corpus Christi, Texas, US, December 9, 2024. (Reuters)
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There Are Fewer Than 100 Ocelots in the US - These Scientists Are Trying to Save Them 

Zookeeper Laura Carpenter of the Cincinnati Zoo observes 5-year-old female ocelot Milla after the wild cat underwent an in vitro fertilization procedure at the Texas State Aquarium in Corpus Christi, Texas, US, December 9, 2024. (Reuters)
Zookeeper Laura Carpenter of the Cincinnati Zoo observes 5-year-old female ocelot Milla after the wild cat underwent an in vitro fertilization procedure at the Texas State Aquarium in Corpus Christi, Texas, US, December 9, 2024. (Reuters)

In the race to save the endangered ocelot, scientists are trekking the United States, pursuing fertility treatments and striving to kickstart a new generation of the wild cat.

Ocelots roamed the southwestern US in the 1800s, but have since dwindled to fewer than 100 in two small breeding populations in South Texas.

While the feline species is found in Mexico, Central America and South America, the Texas cats with striking spotted coats are believed to be the last wild population in the United States.

"Just look at the cat – why would you not want that animal to survive in nature?" said Bill Swanson, the Cincinnati Zoo's director of animal research, who has traveled the country trying to breed captive ocelots in animal institutions with sperm from wild ocelots from South Texas ranch land.

"It's not just saving the ocelot, it's saving the habitat and the ecosystem where it lives, which supports so many other animals that provide those services that let people survive on this planet," he said,

The nonprofit East Foundation, based in San Antonio, manages one of those breeding populations on more than 200,000 acres (810 sq km) of South Texas ranch land containing thorn scrub habitat, a dense covering of short, spiky shrubs that the elusive and nocturnal ocelots adore.

Ashley Reeves, a research veterinarian at the East Foundation, said humans played a major role in the decline of the ocelot, listed in 1982 as an endangered species in the US.

"Back when the fur trade became very popular, they were hunted down for their beautiful fur," Reeves said. "And then also loss of habitat, human encroachment, large cities being built and roadways, so roadways are one of their No. 1 killers today."

Reeves and Swanson have been working on their ocelot project since 2021. The team has tried - unsuccessfully so far - to breed ocelots two ways.

The first is via artificial insemination, in which semen collected from a cat is deposited directly into a female cat's reproductive tract.

The second is in vitro fertilization, in which oocytes, or eggs, are collected from the female cat's body and fertilized with semen in a petri dish before developing into an embryo in an incubator. The viable embryo is then surgically transferred into a cat or frozen to be transferred later.

Of the 13 artificial inseminations and four in vitro fertilization procedures performed in recent years, none have produced a viable pregnancy.

Swanson points to decreased quality in wild ocelot sperm due to signs of inbreeding, environmental stresses like dehydration from drought and decreased motility - the ability of sperm to move - from freezing specimens.

"An ocelot usually has one kitten. That's the normal litter size," Swanson said. "And in the wild, the mother will raise that kitten for a full year until it's old enough to go out on its own. So ocelots are very slowly reproducing animals naturally."

At the Texas State Aquarium in Corpus Christi, Texas, in December, the team extracted two eggs from a five-year-old ocelot named Milla and patiently waited to see if an embryo would form after combining the eggs with wild sperm in a petri dish. After two days of waiting for a fertilized egg to cleave, or rapidly divide and develop into an embryo, the researchers were disappointed to find neither cell cleaved.

"It's disappointing," Reeves said. "But at the same time, science doesn't always go the way you expect it to."

Researchers will spend the next few months trapping wild male ocelots to collect their sperm before resuming fertility procedures in the fall.

By the end of the year, a facility in Kingsville, Texas, will be constructed to house ocelots, provide medical and reproductive care as well as a setting for young ocelots to learn how to hunt in the wild.