Expose-R2 experment: Exploring Mars in low Earth orbit

The Expose-R2 experment on the outside of the Zvezda module of the International Space Station (ISS). 

Credit: DLR

In their quest to understand life's potential beyond Earth, astrobiologists study how organisms might survive in numerous environments, from the surface of Mars to the ice-covered oceans of Jupiter's moon, Europa.

For now, Earth is our only example of an inhabited planet, and studying the limits of habitability on Earth is a major component of astrobiology research.

For this reason, scientists collect data from places on our planet where life is pushed to the absolute limits of adaptability, from the Antarctic to the Arctic, and from smoldering thermal vents to highly acidic rivers.

But locations like the Antarctic Dry Valleys or deep-sea vents in the Pacific aren't the only places in which astrobiologists study life as we know it. Low Earth orbit provides an opportunity to observe Earth-life in the harsh conditions of space.

In the early hours of July 24th, 2014, a new astrobiology experiment began its journey from the Baikonur Cosmodrome in Kazakhstan to the International Space Station (ISS).

BIOMEX (Biology and Mars Experiment) launched onboard a Russian Progress cargo spacecraft and is one of four experiments that make up the EXPOSE-R2 facility, which will be mounted on the exterior of the ISS Zvezda module.

Just six hours after launch, the cargo ship successfully docked with the ISS.

Life on the Station
BIOMEX contains twelve different experimental packages that are designed to help determine life's potential on Mars.

The Institute of Planetary Research at the German Aerospace Center (DLR) is coordinating BIOMEX, but the project involves 25 participating institutions from around the world.

BIOMEX contains numerous chambers that are filled with biomolecules and organisms that include bacteria, archaea, algae, fungi, lichens and mosses.

Replicate samples spread across the compartments are subjected to a range of environmental conditions.

Some samples of each biomolecule or organism are embedded in a simulant Mars soil (ranging from just a single layer of soil to multiple layers), and other samples are left on their own to face the space environment without protection.

Various filters are also being used on the sample chambers to test exposure to different levels of radiation.

By doing this, scientists are able to simulate the solar radiation present at the martian surface. Some of the sample chambers are even pumped full of a simulated Mars atmosphere that is rich in carbon dioxide and pressurized to replicate conditions on Mars.

"To gain real insights into the behavior of biomolecules within a martian environment, we have to check the different parameters we might encounter on Mars," explained Dr. Jean-Pierre Paul de Vera of the German Aerospace Center (DLR) and the principle investigator for BIOMEX.

"This means we will approach, as much as possible on the ISS, martian conditions, including extreme temperature regimes, martian atmosphere by using Mars-like gases in the compartments of EXPOSE-R2, and the radiation regime, which we can never simulate in the labs on Earth."

The samples will spend up to one and a half years outside the space station, and the organisms inside will be monitored with temperature sensors and dosimeters, which monitor radiation exposure.

The goal is to see how exposure to these varied environmental pressures affects the survival of the organisms and the stability of important cellular components like membrane lipids, pigments, proteins and DNA.

The results of BIOMEX will help astrobiologists understand whether or not these biological materials can cope with conditions in the space environment and on Mars, and if being buried in martian soil might aid in their survival.

Tools for the Future
While the samples in BIOMEX are attached to the outside of the station, scientists on Earth will be working with replicate samples in the lab.

Here they will simulate martian conditions as best they can in the controlled environment of the laboratory and monitor the Earth-bound samples with a number of instruments.

View of a Progress vehicle connected to the Zvezda module of the ISS. 

The Zvezda Service Module was the first fully Russian contribution to the International Space Station. 

The module provides station living quarters, life support systems, electrical power distribution, data processing systems, flight control systems and propulsion systems. 

Credit: NASA

At the completion of the experiment, BIOMEX samples will be returned to Earth where scientists will take a close look at the results. In the laboratory, they will examine the stability of biomolecules after they have been exposed to the conditions in low Earth orbit.

This includes studying the signatures they leave behind in the sample chambers, which could be useful on future life-detection missions on Mars.

"BIOMEX is investigating the capacity of instruments to detect selected biosignatures (pigments, membrane composites, lipids etc.) in a Mars-like environment before and after space experiments, and also during Mars simulations in the lab," de Vera told reporters.

The set of spectroscopic instruments they are using on Earth are similar to those currently being eyed for Mars missions in the near future.

They include Raman, IR and UV/VIS spectroscopes. Initial tests in the lab have already turned up some interesting results.

Studies at the German Aerospace Center (DLR) in Cologne and Berlin indicate that biosignatures are altered by temperature and radiation.

This causes their appearance to differ from the signatures we normally observe in Earth conditions.

Beyond Astrobiology
Data from BIOMEX could also have some important applications beyond the realm of astrobiology according to Dr. de Vera.

Studying how biosignatures survive in a simulated Mars regolith might have lessons for archaeology experts on Earth who are looking for radiation-independent (e.g. not carbon 14-dating) methods to study ancient wooden objects.

In particular, the thermogravimetric methodology, which is used by de Vera and his team to test the bounded and remaining water in BIOMEX samples after they have faced the conditions of space, is of special interest for archaeologists.

Raman spectroscopy is also a technique that is growing in prominence for biological studies in numerous fields.

"Raman spectroscopy is used more and more in microbiology, pharmacology and medicine," said de Vera.

"The Robert Koch Institute in Berlin, which is cooperating with us, uses this method (coupled with other methods) to characterise microorganisms that can be harmful to health, and they have to be detected very fast to find out if there could be a risk of an epidemic."

The studies of biofilms in space could have some interesting implications for the health of astronauts and humans on Earth.

On Earth, biofilms are used in some health drinks to trigger the immune system. Studying biofilms in space can help determine whether or not these drinks might be safe for astronauts to consume in orbit, or if the space environment will cause biofilm cultures to rapidly mutate in such a way as to become harmful for consumption.

"Desiccation [removal of water] and radiation protection is also a very important issue," noted de Vera.

"Studies on the exposed samples might give more information about how the most resistant microorganisms are able to shield themselves efficiently, and which substances are responsible for their resistance.

The cosmetic and food industries are interested in these results."

In fact, the Fraunhofer Institute IZI for Cell Therapy and Immunology in Potsdam, Germany is already working with two of the organisms that de Vera and his team are studying.

One is a highly resistant cyanobacteria, and the other is a green algae. Thanks to BIOMEX, these organisms now have a home in low Earth orbit, clinging to the outside of the International Space Station.

The Mars Simulation Facility Laboratory. 

Credit: DLR

Further afield BIOMEX will help astrobiologists understand the potential for habitability on Mars.

If life ever originated on Mars, and if that life operated under the same biological principles as on Earth, could those organisms have adapted to survive on Mars in the present day?

By exploring this question, BIOMEX could help shape the future of Mars exploration, providing guidelines for where robotic explorers might search for signs of life on present-day Mars or signs of ancient life preserved in the regolith.

"With the data obtained by the selected biomolecules as potential biosignatures and which are exposed to the Mars-like conditions in space, we are building up a database that might have significant relevance for future exploration missions to Mars," said de Vera.

"This database might serve as back-up, or a systematically generated reference list that takes into account the martian environmental conditions that might influence the signatures of minerals, and possible fossils or biomolecules from potential extant life forms."

ESA ExoMars could detect bacteria on Mars past and present

An artist’s conception of the European Space Agency’s ExoMars rover, scheduled to launch in 2018. Credit: ESA

Signs of life on the Martian surface would still be visible even after bacteria were zapped with a potentially fatal dose of radiation, according to new research—if life ever existed there, of course.

Using "model" bacteria expected to resemble what microbes could look like on the Red Planet, the research team used a Raman spectrometer—an instrument type that the ExoMars rover will carry in 2018—to see how the signal from the bacteria change as they get exposed to more and more radiation.

The bottom line is the study authors believe the European Space Agency rover's instrument would be capable of seeing bacteria on Mars—from the past or the present—if the bacteria were there in the first place.

Readings from the NASA Mars Curiosity rover recently found that humans on the surface of Mars would have a higher risk of cancer due to the increased radiation level on the surface.

Mars does not have a global magnetic field to deflect radiation from solar flares, nor a thick atmosphere to shelter the surface.

The new study still found the signature of life in these model microbes at 15,000 Gray of radiation, which is thousands of times higher than the radiation dose that would kill a human. At 10 times more, or 150,000 Gray, the signature is erased.

"What we've been able to show is how the tell-tale signature of life is erased as the energetic radiation smashes up the cells' molecules," stated Lewis Dartnell, an astrobiology researcher at the University of Leicester who led the study.

ExoMars 2016 Mission to the Red Planet. 

It consists of two spacecraft – the Trace Gas Orbiter (TGO) and the Entry, Descent and Landing Demonstrator Module (EDM) which will land. 

Credit: ESA

Specifically, the spectrometer detected carotenoid molecules, which can be used to protect a microorganism against difficult conditions in the environment.

The research teams stated that these cartenoids have been proposed as "good biosignatures of life" on Mars.

"In this study we've used a bacterium with unrivaled resistance to radiation as a model for the type of bacteria we might find signs of on Mars."

"What we want to explore now is how other signs of life might be distorted or degraded by irradiation," Dartnell added.

"This is crucial work for understanding what signs to look for to detect remnants of ancient life on Mars that has been exposed to the bombardment of cosmic radiation for very long periods of time."

NASA: Pseudomonas Aeruginosa Bacteria sent into space behave in mysterious ways

Recent experimental findings about bacterial behaviour aboard Atlantis’ STS-132 and 135 missions represent a key step toward keeping astronauts healthy during long-term space missions. 

Above photo shows astronauts of the STS-135 crew performing floating exercises. Credit: NASA

Colonies of bacteria grown aboard the Space Shuttle Atlantis behaved in ways never before observed on Earth, according to a new NASA-funded study from Rensselaer Polytechnic Institute, Troy, New York.

Recent findings provide important evidence of spaceflight's effect on the behavior of bacterial communities, and represent a key step toward understanding and mitigating the risk these bacteria may pose to astronauts during long-term space missions.

The research team, led by Rensselaer faculty member Cynthia Collins, sent the experiment into orbit aboard Space Shuttle Atlantis missions STS-132 on May 16, 2010 and STS-135 on July 8, 2011.

Samples of the bacteria Pseudomonas aeruginosa were cultured for three days in artificial urine.

The space-grown communities of bacteria, called biofilms, formed a "column-and-canopy" structure not previously observed on Earth.

Additionally, biofilms grown during spaceflight had a greater number of live cells, more biomass, and were thicker than control biofilms grown under normal gravity conditions.

Biofilms are complex, three-dimensional microbial communities commonly found in nature. Most biofilms, including those found in the human body, are harmless. Some biofilms, however, have shown to be associated with disease.

"Biofilms were rampant on the Mir space station and continue to be a challenge on the ISS, but we still don't really know what role gravity plays in their growth and development," said Collins, assistant professor in the Department of Chemical and Biological Engineering at Rensselaer.

"Our study offers the first evidence that spaceflight affects community-level behaviors of bacteria, and highlights the importance of understanding how both harmful and beneficial human-microbe interactions may be altered during spaceflight."

Results of the study were published by the journal PLOS ONE April 29, 2013 in the paper "Spaceflight promotes biofilm formation by Pseudomonas aeruginosa."

Beyond its importance for astronauts and future space explorers, this research also could lead to novel methods for preventing and treating human disease on Earth.

Examining the effects of spaceflight on biofilm formation can provide new insights into how different factors, such as gravity, fluid dynamics, and nutrient availability affect biofilm formation on Earth.

Additionally, the research findings could one day help inform new, innovative approaches for curbing the spread of infections in hospitals, Collins said.

More information: For more information about the results, visit: dx.plos.org/10.1371/journal.pone.0062437

Large communities of bacteria in the Mariana Trench

Deep sea trenches act as hot spots for microbial activity because they receive an unusually high flux of organic matter, made up of dead animals, algae and other microbes, sourced from the surrounding much shallower sea-bottom.

An international research team announces the first scientific results from one of the most inaccessible places on Earth: the bottom of the Mariana Trench located nearly 11 kilometers below sea level in the western Pacific, which makes it the deepest site on Earth.

Their analyses document that a highly active bacteria community exists in the sediment of the trench - even though the environment is under extreme pressure almost 1,100 times higher than at sea level.

In fact, the trench sediments house almost 10 times more bacteria than in the sediments of the surrounding abyssal plain at much shallower water depth of 5-6 km water.

Deep sea trenches are hot spots
Deep sea trenches act as hot spots for microbial activity because they receive an unusually high flux of organic matter, made up of dead animals, algae and other microbes, sourced from the surrounding much shallower sea-bottom.

It is likely that some of this material becomes dislodged from the shallower depths during earthquakes, which are common in the area.

So, even though deep sea trenches like the Mariana Trench only amount to about two percent of the World Ocean area, they have a relatively larger impact on marine carbon balance - and thus on the global carbon cycle, says Professor Ronnie Glud from Nordic Center for Earth Evolution at the University of Southern Denmark.

Ronnie Glud and researchers from Germany (HGF-MPG Research Group on Deep-Sea Ecology and Technology of the Max Planck Institute in Bremen, Scotland's (Scottish Association for Marine Science), Japan's (Japan Agency for Marine-Earth Science and Technology),  and Denmark (University of Copenhagen), explore the deepest parts of the oceans, and the team's first results from these extreme environments were published in the widely recognized international journal Nature Geoscience.

Dietary Changes and Milk fats alter gut bacteria leading to degenerative abdominal disease

The rise of inflammatory bowel diseases could be down to our shifting diets causing a "boom in bad bacteria", according to US researchers.

Mouse experiments detailed in the journal Nature linked certain fats, bacteria in the gut and the onset of inflammatory diseases.

The researchers said the high-fat diet changed the way food was digested and encouraged harmful bacteria.

Microbiologists said modifying gut bacteria might treat the disease.

Inflammatory bowel diseases (IBDs), such as Crohn's and ulcerative colitis, affect one in every 350 people in the UK. When the gut becomes inflamed it can lead to abdominal pain and diarrhoea.

The researchers at the University of Chicago said the incidence of the diseases was increasing rapidly.

They used genetically modified mice which were more likely to develop IBDs. One in three developed colitis when fed either low-fat diets or meals high in polyunsaturated fats. This jumped to nearly two in three in those fed a diet high in saturated milk fats, which are in many processed foods.

They also suggest an effective means of dealing with such diseases, by simply reshaping the microbial balance of the gut”

Dr Roy Sleator Cork Institute of Technology

These saturated fats are hard for the body to digest and it responds by pumping more bile into the gut.

This changes the gut environment and leads to a change in the bacteria growing there, the researchers said.

Treatments

One bacterium in particular, Bilophila wadsworthia, was identified. It thrives in the extra bile produced to break down the fats. It went from being incredibly rare to nearly 6% of all bacteria in the gut in the high-fat diet.

Prof Eugene Chang, of the University of Chicago, said: "Unfortunately, these can be harmful bacteria. Presented with a rich source of sulphur, they bloom, and when they do, they are capable of activating the immune system of genetically prone individuals."

However, he said this could lead to possible treatments as the gut bacteria could be "reshaped" without "significantly affecting the lifestyles of individuals who are genetically prone to these diseases".

Commenting on the research, Dr Roy Sleator, from the Cork Institute of Technology, said: "Not only do the authors provide, what is in my opinion, the first credible explanation as to how Western diet contributes to the unusually high incidence in inflammatory bowel disease; they also suggest an effective means of dealing with such diseases, by simply reshaping the microbial balance of the gut."

USB stick can sequence DNA in seconds

It may look like an ordinary USB memory stick, but a little gadget that can sequence DNA while plugged into your laptop could have far-reaching effects on medicine and genetic research.

The UK firm Oxford Nanopore built the device, called MinION, and claims it can sequence simple genomes – like those of some viruses and bacteria – in a matter of seconds.

More complex genomes would take longer, but MinION could also be useful for obtaining quick results in sequencing DNA from cells in a biopsy to look for cancer, for example, or to determine the genetic identity of bone fragments at an archaeological dig.

The company demonstrated today at the Advances in Genome Biology and Technology (AGBT) conference in Marco Island, Florida, that MinION has sequenced a simple virus called Phi X, which contains 5000 genetic base pairs.

Proof of principle
This is merely a proof of principle – "Phi X was the first DNA genome to be sequenced ever," says Nick Loman, a bioinformatician at the Pallen research group at the University of Birmingham, UK, and author of the blog Pathogens: Genes and Genomes.

But it shows for the first time that this technology works, he says. "If you can sequence this genome you should be able to sequence larger genomes."

Oxford Nanopore is also building a larger device, GridION, for lab use. Both GridION and MinION operate using the same technology: DNA is added to a solution containing enzymes that bind to the end of each strand.

When a current is applied across the solution these enzymes and DNA are drawn to hundreds of wells in a membrane at the bottom of the solution, each just 10 micrometres in diameter.

Within each well is a modified version of the protein alpha hemolysin (AHL), which has a hollow tube just 10 nanometres wide at its core.

As the DNA is drawn to the pore the enzyme attaches itself to the AHL and begins to unzip the DNA, threading one strand of the double helix through the pore.

The unique electrical characteristics of each base disrupt the current flowing through each pore, enough to determine which of the four bases is passing through it. Each disruption is read by the device, like a tickertape reader.

OxFord University: Flesh-eating bacteria inspire superglue

A bio-inspired superglue has been developed by Oxford University researchers that can’t be matched for sticking molecules together and not letting go.

It could prove to be a very useful addition to any toolbox for biotechnology or nanotechnology. You could use the glue to grab hold of proteins or stick them immovably to surfaces. You could even use it to assemble proteins and enzymes to build new structures on the nanometre scale.

‘We’re very interested in creating protein assemblies. We want to be able to treat proteins like Lego,’ explains Dr Mark Howarth, who with his graduate student Bijan Zakeri at the Department of Biochemistry developed the superglue. ‘But previously we’ve been limited to ill-controlled processes or have had to build using weak biological interactions.’

The Oxford biochemists came up with their new super-strength molecular glue by engineering an unusual protein from a type of bacteria that can cause life-threatening disease.

While many people carry Streptococcus pyogenes in their throat without any problems, the bacteria can cause infections. Some are mild, like impetigo in infants or a sore throat, but some can kill, like toxic shock syndrome or flesh-eating disease.

What attracted the biochemists’ interest was a specific protein which the bacteria use to bind and invade human cells.

‘The protein is special because it naturally reacts with itself and forms a lock,’ says Mark.

All proteins consist of amino acids linked together into long chains by strong covalent bonds. The long chains are folded and looped up into three-dimensional structures held together by weaker links and associations.

The protein FbaB from S. pyogenes has a 3D structure that is stabilised by another covalent bond. This strong chemical bond forms in an instant and binds the loops of the amino acid chain together with exceptional strength.

Mark and his colleagues reckoned with a bit of engineering they could split the protein around this extra covalent bond. Then, when the two parts were brought together again, they might dock and form this strong bond once more.

The two parts would be locked together immovably – stapling together anything else attached to their tails.That is what the researchers have now demonstrated in this week’s PNAS.

They’ve nicknamed the larger fragment which formed the bulk of the original protein ‘SpyCatcher’. Once SpyCatcher gets hold of the shorter protein segment, ‘SpyTag’, it never lets go.

At least, the researchers with their collaborators at the University of Miami tried to measure the force needed to pull apart SpyTag from SpyCatcher using an atomic force microscope.

But when they pulled on each end, the chemical links holding the proteins to the apparatus broke first. Boiling in detergent won’t separate the protein fragments either.

‘Our system forms rapid covalent bonds with high efficiency and high stability,’ says Mark.

When SpyCatcher and SpyTag are brought together, they bond in minutes with high yield. It doesn’t matter whether it is in acidic or neutral conditions, or whether it is 4°C or 37°C.

They will stick together in test tube reactions or inside cells. And importantly, they don’t stick to other things – there’s no equivalent of getting your fingers stuck to the Airfix model you’re building.

Mark explains that there isn’t really any equivalent way to bind biomolecules together. There are chemical reactions that can join two proteins together covalently but often only small proportions react, they take a long time, or they require UV light, toxic catalysts or reaction conditions that could damage living cells.

The ability to attach SpyCatcher and SpyTag onto other molecules you want to glue together could have many applications. For example, sticking all the enzymes involved in a chemical process into a small factory could speed reactions and increase yields.

Or you might want to bring all the elements together that plants use to turn sunlight into energy with only water as a waste product. Scientists have long wanted to come up with ways of achieving photosynthesis artificially for useable green energy.

But the first uses of the molecular superglue may well be in the research lab, grabbing hold of structures within biological cells. That way you could resist the forces generated by important motors, machines and transporters inside the cell.

Mark and his team are now working on developing the molecular superglue technology through Isis Innovation, the University of Oxford’s technology transfer company.

Bug-Free! A keyboard that cleans itself

It’s not uncommon for keyboards to become the breeding grounds for bacteria and germs. And in a hospital, where doctors and nurses alternate between tending to patients and typing up medical records, the germy computer can be particularly troublesome.

Now, however, health care professionals won’t need to worry about going home sick. In a recent press release, medical technology company Vioguard announced that it has received FDA approval for its first product—a self-sanitizing keyboard.

The keyboard, which is to be used in hospitals, automatically cleans itself by employing the germ-killing properties of ultraviolet light (UV-C). It is able to target microbes (a.k.a. germs) due to their ability to be broken down with just the right amount of ultraviolet light.


Taking on the appearance of any other keyboard, the self-sanitizing version works by automatically retracting into its own light-tight enclosure after use.

Then the UV-C light gets to work—flooding the case and killing any germs that may have been left behind. A quick hand-wave in front of the motion sensor and the keyboard drawer opens, ready for use once again.

Initial testing has shown that the germicidal light was successful in eradicating 99.99 percent of the germs and bacteria that had been lurking on the keyboard.

The system may come as a relief to health care workers who sometimes worry about their own physical conditions—health care associated infections (HAIs) are a real concern in the medical world.

“Conventional computer keyboards have been identified as a key point of transmission of viruses and bacteria, especially within the medical setting,” says Larry Ranta, president and CEO of Vioguard, in the press release. “The Vioguard keyboard takes the guesswork out of sanitization efforts, reduces labour costs, and helps fight the spread of harmful and often deadly superbugs.”

White blood cell chasing a bacteria

Your faeces, my friend, are blowin' in the wind

GO FOR a bracing winter stroll in a major US city and you will be inhaling more than vehicle fumes. 

A new study has demonstrated for the first time that during winter most of the airborne bacteria in three large Midwestern cities come from dog faeces.

Noah Fierer at the University of Colorado, Boulder, found the high proportions of airborne dog faecal bacteria after analysing samples of winter air from Cleveland, Detroit and Chicago. 

His team checked the DNA in their samples against reference banks which "barcode" organisms according to their genes.

They discovered that most of the bacteria they found came from dog faeces by checking the bacterial profiles against reference samples of bugs typically present in soils, leaves and faeces from humans, cows and dogs.

In summer, the proportions of bacteria in the air come almost equally from soils, dog faeces and the leaves of trees. But come winter, the trees have shed all their leaves and aerosols from soils are limited by overlying snow or ice, reducing absolute counts of airborne bacteria by about 50 per cent. 

This means that dog faeces becomes the dominant remaining source.

Fierer says that at the relatively low concentrations found - 10,000 bacteria per cubic metre of air sampled - the bugs are unlikely to cause disease (Applied and Environmental Microbiology, DOI: 10.1128/aem.05498-11).

'Mars in a Bottle' Tortures Bacteria

It's hard to believe that nearly 35 years ago we conducted the first -- and so far last -- experiments to find life on Mars.

In 1976, two NASA Viking landers scooped up some orange Martian soil and attempted to incubate any native microorganisms that might be present. The results were ambiguous as best, and have been hotly debated ever since.

The Viking experiments were criticized as being too premature because in the 1970s we didn't know very much about the Martian environment or its geological history. In fact, the Viking experiments may have actually killed exotic native life say some astrobiologists (Viking's view of Mars is pictured below). We didn’t even know about the existence of extremophiles on Earth back then -- tough microbes that adapt to hostile conditions that would normally kill us.

Before we send another biology experiment to Mars, says a team of researchers at the University of Padova, Italy, let's build our own Martian environment in a lab and see what Earth life forms might survive. Call it a "goldfish bowl" for seeing if life can live on the edge.

Finding a life form able to survive in homemade Martian conditions may have a double payoff says the team, lead by Giuseppe Galletta. It might expand our understanding of the limits of environments where life can survive.

The experiments would also define the limits for how easy or hard it would be to accidentally contaminate Mars with Earth bugs.

The small Martian environment simulators they built (pictured top), called LISA and mini-LISA (Laboratorio Italiano Simulazione Ambienti), make an attempt at duplicating Martian surface conditions.

Inside the mini-Mars habitats, temperature ranges from a maximum of near-freezing in the tropical Martian summer to –200 degrees Fahrenheit (-130°C) in the harsh polar winter. Air pressure is kept at an anemic fraction of a percent of Earth's surface pressure. The bottled atmosphere is 95 percent carbon dioxide with trace elements. Searing ultraviolet (UV) light floods the habitat.

What's handy is there are no time limits on the experiments. The mini-Mars world is refueled with liquid nitrogen weekly to keep it chilly.

Gut Bacteria helps fight Influenza and Lung Disease

Bacteria have their place. They are not always bad and sometimes they are beneficial.

They aid in digestion, help keep our intestines harmoniously balanced, and are even important in diabetes, obesity, and inflammatory bowel disease.

But what about beyond our gut? Scientists found that bacteria can avert the flu by keeping the immune system on alert for seasonal viral intruders.

Mice on antibiotics can’t fight the flu as well as mice that haven’t taken the drugs, researchers say.

Antibiotics quash the immune system’s infection-fighting power by killing friendly bacteria living in the intestines.

For a month, the researchers treated mice with antibiotics commonly given to people with bacterial infections and then they gave them the flu. The treated mice were more susceptible.

Turns out, the naturally-occurring bacteria taken out by antibiotics actually help produce flu-fighters – like immune cells and antibodies that fend off the viral infection.

The gut is where the bulk of the body’s roughly 100 trillion ‘commensal’ – harmless or beneficial – bacteria live [Nature]. And since lungs are normally sterile, it was a bit of a surprise that killing bacteria as far away as the colon would have any effect on how well the lungs could fight viruses [Science News].

“It seems that the commensal bacteria in the gut are providing a crucial signal throughout the body that prepares the body for fighting infection,” says lead author Akiko Iwasaki of Yale. “And it’s probably not only restricted to lungs.”

The findings suggest that long-term use of antibiotics could hamper our ability to fight influenza, Iwasaki says, perhaps even impair the effect of a vaccine.

Additionally, it also implies that our diet affects our ability to fight viruses by influencing the composition of our beneficial bacteria. For example, probiotic treatments, like yogurt, may help stimulate our immune systems during flu season.

The study was published in the Proceedings of the National Academy of Sciences this week.

Consuming Tequila (plants) helps Build Stronger Bones

The plant that gave the world tequila contains a substance that seems ideal for use in a new genre of processed foods -- so-called "functional foods" -- with health benefits over and above serving as a source of nutrients, scientists reported at the 239th National Meeting of the American Chemical Society (ACS) in San Francisco on March 23. Foods spiked with "fructans" from the agave plant may help protect against osteoporosis by boosting the body's absorption of calcium and could have other health benefits, they said.

"Fructans are considered functional food ingredients because they affect body processes in ways that result in better health and reduction in the risk of many diseases," said Mercedes López, Ph.D., who delivered the report. She is with the National Polytechnic Institute, Guanajuato, Mexico. "Experimental studies suggest that fructans may be beneficial in diabetes, obesity, stimulating the immune system of the body, decreasing levels of disease-causing bacteria in the intestine, relieving constipation, and reducing the risk of colon cancer."

Fructans are non-digestible carbohydrates. They consist of molecules of fructose -- the sugar found in honey, grapes, and ripe fruits -- linked together into chains. Rich natural sources include artichokes, Jerusalem artichokes, garlic and onions, and chicory. Fructans do not occur in tequila, however, because they change into alcohol when agave is used to make tequila, López said.

So-called "inulin-type" fructans from chicory find wide use in the United States and other countries in ice cream, breakfast cereals, baked goods, sauces, beverages, and other foods. Small fructans have a sweet taste, while those formed from longer chains of fructose have a neutral taste and give foods a smooth, pleasant texture. Scientific studies have suggested that fructans stimulate the growth of healthful bacteria in the large intestine in a way that increases the body's absorption of minerals, including the calcium and magnesium important for bone growth.

In the new study, López and colleagues set out to determine what effects agave fructans actually have on bone growth. They tested the effects of agave fructans on laboratory mice, used as stand-ins for humans in such research. Mice fed agave fructans absorbed more calcium from food, excreted less calcium in their feces, and showed a 50 percent increase in levels of a protein associated with the build-up of new bone tissue.

"These results suggest that the supplementation of the standard diet with agave fructans prevented bone loss and improved bone formation, indicating the important role of agave fructans on the maintenance of healthy bone," López said. "They can be used in many products for children and infants to help prevent various diseases, and can even be used in ice cream as a sugar substitute."

Newly engineered enzyme is a powerful staph antibiotic

Lysins that are effective against drug-resistant staph bacteria bore a hole through their cell walls.

The bacterium's contents ooze out, instantaneously killing it. (Credit: Image courtesy of Rockefeller University)

Newly engineered enzyme is a powerful staph antibiotic

With their best chemical antibiotics slowly failing, scientists are increasingly looking to nature for a way to control deadly staph bacteria -- the culprit behind most hospital infections.

Naturally toxic for bacteria, enzymes called lysins have the promising ability to obliterate staph, but the problem is producing large enough quantities of them to study how they work.

Rockefeller University scientists have now overcome this barrier by engineering a lysin that not only kills multidrug-resistant Staphylococcus aureus (MRSA) in mice, but also works synergistically with traditional antibiotics that have long been shelved due to resistance.

For the past five years, Vincent A. Fischetti, head of the Laboratory of Bacterial Pathogenesis and Immunology, and his colleagues have tried to clone a lysin that specifically targets staph, but they always ran into the same problem.

Although hundreds of thousands of lysins could be expressed in an engineered cell, they all would stick together forming an insoluble clump, rendering them inactive. "They were useless; a real thorn in our side," says Fischetti. "We've come across some problems cloning lysins for other bacteria, such as strep, but nothing to this extent."

Lysins, proteins derived from the viruses that have been infecting bacteria for billions of years, have two basic components. One acts as a recognition system to identify the specific bacteria species it has evolved to target; the other works like a molecular power drill that bores holes through the bacterium's cell wall, killing the organism. Together, these two components work so quickly and so efficiently that bacteria have no time to develop resistance.

Read the full article here

NASA Martian sheen: Life on the rocks

WHEN NASA's Viking landers touched down on Mars, they were looking for signs of life. Instead, all their cameras showed was a dry, dusty - and entirely barren - landscape.

Or so it seemed. But what the 1976 Viking mission, and every subsequent one, saw was a scene littered with rocks coated with a dark, highly reflective sheen. That coating looks a lot like a substance known on Earth as "rock varnish", found in arid regions similar to those on Mars. The latest evidence hints that rock varnish is formed by bacteria. Could there be microbes on Mars making such material too?

Rock varnish has long been something of a mystery. It is typically just 1 to 2 micrometres thick, but can take a thousand years or more to grow, making it very hard to discover whether biological or purely chemical processes are responsible. If it is biological, though, the race will be on to discover whether the same thing has happened on Mars - and whether microbes still live there today.

If you go to Death Valley in California, you can find rock varnish covering entire desert pavements. Also known as desert varnish, it forms in many places around the globe, and despite its glacial growth rates, can cover vast areas.

The smooth, high sheen, dark brown-to-black coating is mainly made up of clay particles, which bind the iron and manganese oxides that give the coating its mirror-like reflectivity.

In the Khumbu region of Nepal, not far from Mount Everest, it has turned the boulders black. Halfway around the world, it enabled ancient peoples to create the Nazca Lines in the Peruvian desert.

These giant, elaborate images - some over 200 metres across and created over 1000 years ago - were made by simply removing rows of varnished stones to exposing the lighter stones or soil beneath.

George Merrill coined the phrase desert varnish in 1898, while working for the US Geological Survey (USGS). No one really studied it, though, until 1954, when Charles Hunt showed that the veneer forms on many different rock types - meaning that it wasn't simply a chemical production from a certain kind of rock and prompting the first questions about where it might come from (Science, vol 120, p 183). Hunt went on to find rock varnish in humid regions, tropical rainforests and at high altitudes in the Alps and the Rocky mountains.

Theories on how rock varnish forms weren't long in coming - and, initially at least, biology didn't get a look-in. In 1958 Celeste Engel of the USGS and Robert Sharp from the California Institute of Technology explained it as a chemical weathering phenomenon similar to iron oxide stains - red/orange coatings arising when iron particles from the air collect on the surface of rocks and bind together when made wet by dew (Geological Society of America Bulletin, vol 69, p 487).

Read the full article here ....

AIDS /HIV and Circumcision: Reduces microbial neighbourhood

A flap of foreskin isn't the only thing missing after a circumcision. Microbes that call the penis home disappear, too, which could explain why the procedure reduces a man's chance of contracting HIV.

"The microbes change dramatically," says Lance Price, a microbiologist at the Translational Genomics Research Institute in Flagstaff, Arizona, whose team identified thousands of microbes on the penises of 12 HIV-negative men. All had participated in a clinical study in Uganda which showed that circumcision halves the chances of getting the virus.

The team discovered a total of 38 families of bacteria on the men's penises before circumcision, and 36 a year after. But the make-up of these communities had swung. Gone were a diverse population of bacteria intolerant of oxygen and linked with vaginal infection; now there was a more homogenous air-loving lot, more typical of other patches of skin.

Price thinks that some of the expelled bacteria provoke an immune reaction on an uncircumcised penis, causing specialised immune cells to shuttle HIV throughout the body.

More of the Article here .......

Unhapiness of Blue Birds: Losing their Sparkle

Brightly coloured birds can become infected with bacteria that eat the coating on their feathers. That in turn can affect the health of the birds and dull their plumage.

The discovery comes from a study that found that 99% of all Eastern US bluebirds srveyed, were infected with feather-degrading bacteria. Such bacteria were first discovered a decade ago, but the latest research is the best evidence yet that the bugs affect the colour and general health of the birds.

New to Bird studies

"Feather-degrading bacteria are relatively new to ornithologists," says Alex Gunderson of Duke University in Durham, North Carolina, US. "The first report of their occurrence on wild birds was published only ten years ago."

Since then, scientists have found that most species of wild bird probably harbour some feather-degrading bacteria in their plumage, sometimes of more than one species.

Impacts on their hosts

Feather-degrading bacteria work by hydrolysing the protein beta-keratin, which constitutes over 90% of a feather's mass but these bugs are usually found in a minority of birds sampled, and it has not been clear what impact they have on their hosts.

So Gunderson and colleagues Mark Forsyth and John Swaddle of the College of William and Mary in Williamsburg, Virginia, US surveyed a population of Eastern bluebirds (Sialia sialis) living in Virginia.

They found that 99% of all the birds surveyed carried feather-eating bugs. The full report can be found in the Journal of Avian Biology.