Letting Microbes Do the Dirty Work

Letting Microbes Do the Dirty Work—Not to Mention Boost Energy, Reduce Greenhouse Gas Emissions

Microbes can convert oil into methane and scientists may have figured out how to harness the process

 

 
MICROBES AT WORK: These microbes, stained with a fluorescent dye for visibility, consume oil deep below the earth, eventually converting it to methane.

Millions of years ago, the microbes in river bottoms disappeared into the earth, buried by successive layers of sediment. Over hundreds of millions of years, these microbes—syntrophic bacteria and methanogenic Archaea—evolved to thrive in this underworld, slowly consuming the rich hydrocarbons that surrounded them in the form of oil. As a result, a large amount of the planet's petroleum stash has been ruined, becoming instead a "hot spot" for deep microbial life that consumes it and taints the rest with sulfur and other byproducts. Over time, however, these microbes finish their feast, leaving behind oil transmuted into methane—another, cleaner fossil fuel. Now researchers think they may have figured out how this process works and how to accelerate it to create a vast new energy resource.

"You're looking at an increase equivalent to the same amount of energy as conventional oil reserves in the world today," says petroleum geologist Steve Larter of the University of Calgary in Canada, a member of the team investigating the microbial process. "It's potentially a game changer if it can be demonstrated."

Larter and his colleagues used test tubes to demonstrate exactly how the microbes, over time, convert oil into methane. The tubes, laced with nondegraded oil from the North Sea and microbes from present-day river sediment that are accustomed to living without oxygen, produced the same levels of methane and other byproducts typical of degraded or "heavy" oil in reservoirs worldwide, the researchers report in Nature.

By fermenting unrecoverable heavy oil into methane, the microbes could boost energy supplies; methane can be burned in power plants to produce electricity. "At a conventional petroleum reservoir, you get 35 percent of the oil out of the ground and 65 percent remains in the ground," says microbial ecologist Ian Head of Newcastle University in England, another team member. "The equivalent figure for gas is 70 percent and 30 percent. If we can convert oil to methane, then the recovery of energy goes up."

A trillion cubic feet of methane can be generated from a billion barrels of heavy oil, Larter estimates, and the world contains at least six trillion barrels of such oil. "It will take less energy to recover," team member and Newcastle organic geochemist Martin Jones says. Plus, just knowing how the microbes operate allows the pinpointing of the better oils within a given field. "Biodegradation models are actually key for targeting the best quality oils, or sweet spots, in biodegraded oil fields," notes team member Jennifer Adams, a Calgary geologist.

Further, burning methane, itself a potent greenhouse gas, to generate electricity produces less carbon dioxide than burning oil or coal. "It's not environmentally neutral but it's certainly an improvement," Head notes.

The researchers plan to determine if this microbial conversion can be boosted in existing reservoirs by 2009 by adding nutrient-rich wastewater to them. "The microorganisms feed on the oil hydrocarbons. We just added some fertilizer, including nitrate and phosphate to enable them to grow faster," Head says. "This is a bit like giving the microbes a balanced diet."

If giving the microbes a balanced diet proves effective, then a vast new store of climate-friendlier fossil fuel might become available. But that gas will have to be recovered quickly after the microbes do their work. "Methanogenesis is still active today or was until recently," Adams notes. "Because there is very little gas found in these reservoirs, that also means that most of the generated gas leaked out of these reservoirs."

Farther down the road, direct production of hydrogen—a potential energy carrier with few known environmental drawbacks—might be possible. "Zapping the methanogens and accelerating the syntrophs, plus some clever engineering, may enable hydrogen production—but that's much more difficult, " Larter says. "If you could recover molecular hydrogen from the reservoir, you've got a zero-carbon energy source from fossil fuel."

In the meantime, the process shows the power of microbes to literally change the world. "Most of the world's oil has been generated by microorganisms over geologic time scales," Head says. "Very small microorganisms have global effects."

The Secret to a Longer (Worm's) Life: A Breath of Poison Gas

The Secret to a Longer (Worm's) Life: A Breath of Poison Gas

Small quantities of toxic hydrogen sulfide in the air lengthen life in a nematode by 70 percent

 

 
SULFUR SURPRISE: Rather than sending a nematode into suspended animation, an atmosphere with boosted levels of hydrogen sulfide extends its life by 70 percent.

Consider the life of a nematode: Caenorhabditis elegans, a diminutive, soil-dwelling, hermaphroditic worm that has had its entire genetic code (all base pairs) mapped. Coupled with its reproductive potential, this creature makes a perfect lab specimen. Each worm can expect to live for only a few weeks—unless it is lucky enough to reside in an atmosphere laced with small quantities of hydrogen sulfide. At concentrations of just 50 parts per million, the toxic gas can extend worm longevity by as much as 10 days.

"They were able to withstand higher temperatures than animals that did not have hydrogen sulfide and they were more long lived," says biologist Mark Roth of the Fred Hutchinson Cancer Research Center in Seattle, who teamed with Hutchinson biologist Dana Miller on the study. "They lived 70 percent longer, which is considerably longer. If you add 70 percent to your own life that's a lot."

There is currently no reason to believe that hydrogen sulfide, which is deadly at high concentrations, will have the same effect on humans, although Roth and others have shown that it can put mice into a state of suspended animation. Roth and his colleagues are currently assessing the safety of low concentrations of the gas in humans in order to assess its potential to place removed organs into a state of suspended animation for longer, better storage prior to transplant or even to put critically injured patients into the state to enable more time for lifesaving interventions. 

That potential remains unproved and, in this case at least, H₂S has rendered surprising results. Contrary to Roth's expectations, the worms thrived instead of entering a suspended state  when exposed to the gas. And when subjected to high temperatures (95 degrees Fahrenheit, or 35 degrees Celsius), those in the more sulfurous atmospheres lived eight times longer than their peers.

The biologists are not sure exactly why this occurs but they did discover that the benefits of  H₂S were lost when they removed the gene known as sir-2.1—linked to long life. "It's a demonstration of the requirement or need for that gene product to have sulfide work its magic," Roth says.

The ultimate goal, he says, is to understand the role H₂S plays in maximizing survival, whether in worms, mice or, potentially, people. But the long history of the healing effect of natural sulfur springs—volcanic fissures that emit sulfurous water and gases, such as  H₂S—attests to the fact that the tiny nematode is certainly not the first hint that hydrogen sulfide might have beneficial properties.

Shake, Rattle and Respond: Early Warning System for Earthquakes

Shake, Rattle and Respond: Early Warning System for Earthquakes

By analyzing earthquakes when and where they strike, a computerized system could save lives 

 
EARLY WARNING: As little as seconds advance warning of earthquakes could save lives by prompting automatic shutdown of dangerous infrastructure, such as gas pipelines.

When an earthquake strikes, seismic waves spread from the epicenter, following the patchwork quilt of faults and geology in California, for example. The violent shaking these waves may trigger can topple buildings, rupture water mains and wreak havoc on industrial infrastructure. But by making quick computer analyses in seismographic stations near the epicenter, warnings can be relayed in seconds, allowing people to take safety precautions and critical infrastructure to be shut down, scientists reported this week at the fall conference of the American Geophysical Union in San Francisco.

"What we're doing with early warning is predicting the ground motion after we know the earthquake is underway," says seismologist Richard Allen of the University of California, Berkeley. "Any computerized system can start to do things very rapidly, rapidly enough so we can implement our response before the ground stops shaking."

Such a system, developed by Allen and his colleagues, is currently being tested in California's roughly 300 seismometer stations and provided 10 seconds of warning for the San Jose temblor that measured 5.4 on the Richter scale on October 30.

Japan and Europe already have such warning systems, which have proved useful in preventing fires, one of the major secondary impacts of powerful earthquakes. "Actions that can be made to prevent fires is just to have [an] automatic system to switch off gas supply, also electricity," says geophysicist Paolo Gasparini of the University of Naples–Federico II of the systems operating in that Italian city as well as in Istanbul and Bucharest.

The Japanese system, which began operation on October 1, has already provided warnings from two large quakes. "In both cases, the information was disseminated successfully," says seismologist Osamu Kamigaichi of the Japan Meteorological Agency. "False alarms—very, very few."

But Allen says that California would have to build an additional 600 stations and upgrade its existing network to create a robust early warning system for the state, which could cost as much as $30 million.

Such a system could provide as much as a minute's notice for the Bay Area, for example, if an earthquake struck in the Mendocino triple junction, a highly active seismic conjunction where three plates meet off the northern California coast. "The final goals of the project are to assess the amount of warning time a system like this could provide and look forward to what might be necessary," Allen says. "Even if it's a very small amount of time, it could be useful."

Thunder, Hail, Fire: What Does Climate Change Mean for the U.S.?

Thunder, Hail, Fire: What Does Climate Change Mean for the U.S.?

The regional effects range from more wildfires in the west to stronger storms in the east. 

 
STORMY WEATHER: Climate change impacts in the U.S. range from more severe summer thunderstorms in the east to more wildfires in the west.

The U.S. heartland can look forward to hotter, wetter summers, according to the latest climate research. Global warming will cause more severe thunderstorms—convective cloud fronts that could produce wind gusts of 58 miles (93 kilometers) per hour, 0.75-inch (1.9-centimeter) size hailstones and even more frequent tornadoes—in the region, according to research led by atmospheric scientist Robert Trapp at Purdue University. At the same time, according to independent environmental consultant Kristie Ebi, heat waves like the one in Chicago that killed 700 people in 1995 will become more commonplace.

"Climate change is projected to increase the frequency, intensity and duration of heat waves in the Midwest," says Ebi, an Intergovernmental Panel on Climate Change (IPCC) report author. "In addition, heat waves are projected to be hotter."

Of course, the U.S. Midwest is not the only region of the world that is being affected by climate change. Signs of global warming are beginning to appear everywhere: from runaway ice melt in the Arctic to slowly drowning islands in the Pacific. "Changing climate conditions are already happening," says Eileen Claussen, president of the Pew Center on Global Climate Change, which today released a report on regional impacts in the U.S. "It is clear that there is an immediate need for strong national and international policy action."

The reports findings, in addition to increased heat waves, include:

Western Wildfires—The increasingly destructive and widespread fire seasons of recent years are likely to continue due to a combination of increased drought and land development encroaching on naturally burning landscapes, along with a climate change–induced fuel boom (enhanced plant growth and a shift to more woody species) exacerbated by fire-suppression efforts leading to more abundant plant matter to fuel violent blazes, according to ecologist Dominique Bachelet of Oregon State University in Corvallis and The Nature Conservancy. "The deadly combination of human behavior and climate change means we will likely see more wildfires like those in 2007," she says.

Gulf Coast Swamped—Human engineering efforts such as levees have reduced the ability of the wetlands of Louisiana and other Gulf Coast states to keep pace with subsiding land and rising sea levels, according to coastal scientist Robert Twilley of Louisiana State University in Baton Rouge. "If soil formation cannot keep pace," he says, "inundation of wetlands from rising seas will essentially drown these landscapes, and wetlands will convert to open waters." That, in turn, will make nearby communities far more vulnerable to the effects of storm surges, such as the one caused by Hurricane Katrina in 2005.

"Dead Zones" Deader—One of a number of large and growing seasonal areas in bodies of water from which all oxygen has been leeched drives the degradation of Chesapeake Bay. A "dead zone" is a place devoid of the fish and bottom dwellers, such as the crabs and other shellfish, for which the bay is famous. Marine scientist Donald Boesch, president of the University of Maryland Center for Environmental Science, warns that climate change will also complicate the already difficult task of restoring this important watershed and food source. "Climate change impacts are not straightforward," he says, "but are multiple and interactive."

And the Pew report is not the only research to examine regional impacts.

Stronger Storms—Much of the country will experience severe thunderstorms, but major eastern and southeastern cities are likely to see the largest jumps in storm frequency, according to Purdue's Trapp—a finding buttressed by a NASA study earlier this year. "Our analysis suggests the possibility of an increase of up to 100 percent or more in locations such as Atlanta and New York," the researchers wrote in this week's Proceedings of the National Academy of Sciences.

As a result, these experts say efforts to combat climate change must focus not only on reducing greenhouse gas emissions that drive global warming but also on adjusting to the changes already underway. "The challenge we have with adaptation is trying to understand the specific impacts of climate change on a region," Boesch says. Nevertheless, "adaptation is going to be essential because we cannot avoid climate change entirely."

A 'Flower' That Delivers Disease-Killing Treatments to Mosquitoes

A 'Flower' That Delivers Disease-Killing Treatments to Mosquitoes

In development: an artificial flower that kills pathogens in disease-carrying mosquitoes but spares the bugs 

DON'T KILL THE MESSENGER: The PROVECTOR is designed to use visual, olfactory and chemical signals to entice mosquitoes to ingest antimalarial and antiviral treatments that inhibit the development of pathogens.

The most common way of fighting diseases like malaria, dengue fever, and West Nile today is to try to wipe out the mosquitoes carrying them and treat those who have been infected. Now there's an alternative on the horizon that promises to be safer and cheaper by zapping the germs while sparing the mosquitoes. The technology is hidden in an artificial flower designed to attract mosquitoes and treat them with pathogen-killing drugs that allow the insects to live and continue to perform important functions such as pollinating flowers and serving as food for animals and other insects.

MIT Holding, Inc., a Savannah, Ga., pharmaceuticals distributor, says its PROVECTOR "flower" reduced the number of viruses that cause dengue and parasites that cause malaria in mosquitoes in lab settings.

Although company is still considering what type of flower the PROVECTOR will resemble, the product is designed to use visual, olfactory and chemical signals to entice mosquitoes to ingest antimalarial and antiviral treatments that inhibit the development of the pathogens. This is a vastly different approach to current methods of fighting insect-borne diseases that involve treating populations with expensive preventive medications (which can have serious side effects and may not work), the wholesale killing of the insects using toxic pesticides and / or treating the infected bite victims.

A major problem with current treatments for malaria—a long-lasting, potentially fatal blood disease that kills more than 2.7 million people a year, according to the World Health Organization—is that the parasites may become drug-resistant; in such cases, they are spread along with the disease. A group of researchers led by Pennsylvania State University biology professor Andrew Read recently published findings on the Proceedings of the National Academy of Sciences USA Web site that indicate "the more drugs you use, the worse you make the situation in terms of the evolution of drug resistance."

Lest you worry about the faux flower's impact on humans and other living things: the flower portion of the PROVECTOR is covered by a membrane that protects people, bees and other animals that touch it but is thin enough to be penetrated by a mosquito's long, pointy proboscis. Tests have shown that the chemicals inside the PROVECTOR not only kill pathogens but also suppress the development of Plasmodium parasites that cause malaria if a mosquito encounters them after being treated. "There appears to be a strong prophylactic action in the mosquito," says Dr. Thomas Kollars, MIT Holding's chief scientific advisor and director of the Biodefense and Infectious Disease Laboratory at Georgia Southern University's Jiann-Ping Hsu College of Public Health in Statesboro.

Kollars says PROVECTOR'S drug—which is still being developed—will function similar to doxycycline, an antibiotic that slows or kills parasites in the blood that cause malaria and is taken to prevent the disease before traveling to (and while in) areas where malaria has been reported.

The impetus for Kollars's work began about a decade ago when he was working as a disease outbreak investigator in Thailand. "We were testing antimalarial drugs for the army and their effects on mosquitoes," he says. There are antimalarial drugs available to prevent people from contracting the disease and treatments for those who actually get it, but few people in the most vulnerable regions—such as parts of Africa and Asia—can afford the tab. "We needed to find a treatment that was in the $5-to-$10 range," he says, adding that the goal is to offer the PROVECTOR for less than $5 a flower.

The PROVECTOR will be designed to last about a year before its artificial petals need to be replaced. The product's lifespan will depend upon the mosquito population in a particular area and the amount of chemicals that they ingest.

Another dangerous mosquito-borne disease that Kollars hopes to stop is dengue fever, a disease in tropical areas that can cause headache, rash, achy joints and, in some cases—mostly in very young children—can be fatal if the victim goes into shock. "Our goal is also to develop the technology," Kollars says, "and then transfer that knowledge to help developing countries so they can produce them."

MIT Holding says it will cost about $3.7 million to conduct the next round of product development and testing, which will include trying out PROVECTOR on mosquitoes in rural Georgia come spring and in the Florida Everglades next summer. "We hope to have received some funding by next fall for overseas trials," Kollars adds. He says his team is testing four different prototypes of PROVECTOR to come up with the most effective mix of color and chemicals—not to mention, disposable petals that are biodegradable.

"PROVECTOR alone isn't the answer," Kollars acknowledges, "but it will interdict at a different stage than other treatments for malaria and other diseases. I've seen kids dying of malaria; it behooves those of us who can do something to do something."