Georgia Tech researchers found many types of bacteria, include E.coli, in the middle to upper regions of the troposphere. (Photo: USDA)

Scientists have discovered a considerable number of living microorganisms, including bacteria, in the middle to upper regions of the troposphere, the region of our atmosphere that’s about seven to 20 kilometers above the Earth’s surface.

Researchers from the Georgia Institute of Technology said their findings might help other scientists learn more about the role microorganisms play in forming ice that may impact weather and climate.

Health and medical experts studying the transmission of disease could also benefit by gaining new insight into long-distance transport of bacteria.

Conditions in the troposphere cannot support most other forms of life without the aid of special equipment. Temperatures there can drop to as low as -55° C and the air pressure and density are considerably lower than on earth.

Microorganisms, such as bacteria, are plentiful and can be found everywhere on the Earth and in the sea.

These hardy little forms of life not only survive but actually thrive in some of the harshest conditions known to man. They live within other forms of life, such as the human body; in the soil and the air surrounding us; in scalding hot springs; the great depths of the ocean; and inside rocks deep within the Earth’s crust.

A view outside the window of a DC-8 aircraft as air samples are gathered for a NASA study. Georgia Tech scientists found living microorganisms in the samples. (Photo: NASA)

The microorganisms  documented by Georgia Tech scientists were gathered from air samples recovered as part of NASA’s 2010 Genesis and Rapid Intensification Processes (GRIP) program, which studies low- and high-altitude air masses associated with tropical storms.

NASA gathered the air samples from aboard a DC-8 aircraft that flew over both land and ocean, including the Caribbean Sea and portions of the Atlantic Ocean during and after two major tropical hurricanes in 2010, Earl and Karl.

Attaching a special filter system developed by the Georgia Tech team to the aircraft’s outside air sampling probes, researchers were able to collect numerous particles, including the microorganisms.

Once the air samples were taken, the filters were removed from the aircraft and sent to researchers for examination.

Rather than resorting to conventional cell-culture techniques to make their analysis, the researchers instead used genomic techniques, including polymerase chain reaction (PCR) – a biochemical technology used in molecular biology that magnifies a piece of DNA, allowing scientists to generate millions of copies of the DNA sequence, as well as gene sequencing to spot and estimate the quantities of microorganisms contained within the air samples.

The researchers found more bacteria than fungi among the microorganisms.

“We did not expect to find so many microorganisms in the troposphere, which is considered a difficult environment for life,” said one of the study’s authors, Kostas Konstantinidis, an assistant professor at Georgia Tech. “There seems to be quite a diversity of species, but not all bacteria make it into the upper troposphere.”

Terry Lathem, a graduate student in Georgia Tech’s School of Earth and Atmospheric Sciences, aboard a NASA DC-8 aircraft while gathering samples of microorganisms in the atmosphere. (NASA)

The living bacterial cells found made up about 20 percent of the total particles detected within the size range of 0.25 to 1 microns in diameter.

Air samples taken over the ocean were found to contain mostly marine bacteria, while primarily terrestrial bacteria was found in samples taken above land.

The researchers also found that hurricanes had a major impact on the distribution and dynamics of microorganism populations.

Kostas Konstantinidis joins us for this weekend’s radio edition of Science World.  He’ll tell us how these findings could help advance research in climatology and medicine.

Check out the right column for scheduled air-times or listen now to the interview below.

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Scanning electron micrograph of very small and numerous bacterial cells inhabiting icy brine waters in Antarctica’s Lake Vida. (Photo: Christian H. Fritsen, Desert Research Institute)

Scientists say they have found ancient microbial life in dark and very salty water some 20 meters below the surface of a frozen and isolated Antarctic lake. The finding could provide scientists with insight into how life could possibly exist in the most extreme environments on Earth as well as elsewhere throughout the cosmos.

In a study recently published in the Proceedings of the National Academy of Science (PNAS) the researchers say they took the microbes from the Antarctic’s Lake Vida, which contains no oxygen but has the highest nitrous oxide levels found in any natural bodies of water on Earth. The scientists describe the icy environment in which the sample microbes were taken as a briny liquid, about six times saltier than normal seawater and with an average temperature of minus 13.5 degrees centigrade.

“This study provides a window into one of the most unique ecosystems on Earth,” said lead author Dr. Alison Murray from the Desert Research Institute (DRI) in Reno, Nevada. “Our knowledge of geochemical and microbial processes in lightless icy environments, especially at subzero temperatures, has been mostly unknown up until now. This work expands our understanding of the types of life that can survive in these isolated, cryoecosystems (ecosystems found in ice) and how different strategies may be used to exist in such challenging environments.”

Previous studies going back to 1996 show the Lake Vida brine and its microbial residents have had to do without outside resources that normally support life (i.e.: sunlight or oxygen) for more than 3,000 years. Despite what many would consider being an unlivable habitat, the researchers in this project found that the polar lake supports what they call a surprisingly diverse and large community of bacteria that can survive the harsh conditions.

To ensure that their samples and the microbe’s ecosystem weren’t affected or contaminated by human or other external influences, the researchers developed specialized equipment and a set of very strict procedures when they set out to retrieve them during expeditions to the Antarctic back in 2005 and 2010.

Members of the 2010 Lake Vida expedition team use a sidewinder drill inside a secure, sterile tent on the lake’s surface to collect samples for their research. (Photo: Desert Research Institute, Emanuele Kuhn)

Regarding the high levels of nitrous oxide that was found in the lakes salty water, the scientists say that geochemical analyses are suggesting that the N₂O was generated by chemical reactions between the salty water and the lake’s iron-rich sediments. The chemical reaction also produced an amount of molecular hydrogen, which the researchers say may be what has been providing the energy that was needed to sustain the community of diverse microbial life.

“It’s plausible that a life-supporting energy source exists solely from the chemical reaction between anoxic salt water and the rock,” explained co-author Dr. Christian Fritsen, also from DRI.

“If that’s the case,” Murray said, “this gives us an entirely new framework for thinking of how life can be supported in cryoecosystems on earth and in other icy worlds of the universe.”

Murray said that the scientists involved with the project are continuing their research by analyzing the non-organic components, the chemical interactions between Lake Vida brine and sediment, and by using various methods of genome sequencing, and are learning more about their rare microbial find.

They also suggested the research and findings produced for this study could also provide some help to others who conduct investigations into possible cryoecosystems that might be found in the soil, sediments, wetlands, and other lakes that lie beneath the Antarctic ice sheet.

A western honeybee (Photo: Wolfgang Hägele via Wikimedia Commons)

A new study finds prolonged antibiotic use by beekeepers might play a role in the mysterious drop in honey bee populations in the United States.

Yale researchers found genetic evidence that helpful bacteria, which normally live the bellies of honeybees, have become highly resistant to the antibiotic tetracycline, possibly weakening the bees’ ability to fight disease.

Researchers say decades of use may have unknowingly encouraged antibiotic resistance by genetically altering the beneficial bacteria.

Past studies show helpful bacterial play an important role in protecting the honeybee by neutralizing toxins found in their diets while also helping fight off various pathogens.

The  researchers have identified eight different tetracycline resistance genes among U.S. honeybees that were exposed to antibiotics.  Those same resistance genes were missing in bees from countries where antibiotic use is banned.

“It seems to be everywhere in the U.S.,” says Nancy Moran of Yale University, a senior author on the study. “There’s a pattern here, where the U.S. has these genes and the others don’t.”

In the 1950s, beekeepers started using the antibiotic oxytetracycline, a compound similar to tetracycline, which is commonly used in humans. They were trying to fight a devastating bacterial disease called foulbrood, which can wipe out a hive more quickly than beekeepers can react to the infection.

But after years of use  the microorganisms eventually acquired a resistance to tetracycline, possibly weakening the honeybee’s resistance to other diseases.

“It seems likely this reflects a history of using oxytetracycline since the 1950s,” says Moran. “It’s not terribly surprising. It parallels findings in other domestic animals, like chickens and pigs.”

A beekeeper tends to a beehive. (Photo: Emma Jane Hogbin via Creative Commons at Flickr)

The researchers took bee samples from the Czech Republic, New Zealand and Switzerland, which do not allow their beekeepers to use the antibiotics.

Researchers found  those bees had only two or three different resistance genes and even then only in very low numbers, suggesting that prolonged antibiotic use in the US bees may have played a role in developing the resistance genes.

Moran  points out that the antibiotic-resistant genes researchers found in the bellies of the honeybee do not pose a direct risk to humans.

Those microorganisms, according to Moran, “don’t actually live in the honey, they live in the bee. We’ve never actually detected them in the honey. When people are eating honey, they’re not eating these bacteria.”

Nancy Moran joins us this weekend on the radio edition of Science World.  She tells us more about how treatment meant to strengthen honeybee hives in the U.S. may have actually weakened them instead. Tune in (see right column for scheduled times) or check out the interview below.

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