Tag: Bacteria

Mars Surface May Be Too Toxic For Microbial Life

mars surface

The combination of UV radiation and perchlorates common on Mars could be deadly for bacteria.
The hope for Martian life took another blow today. As Ian Sample at The Guardian reports, a new study suggests that in the presence of ultraviolet light, perchlorates, a class of chemical compounds widespread on Mars’ surface, turn deadly for bacteria.

The presence of perchlorates isn’t new. Viking 1 and 2 spacecraft detected perchlorates when they landed on the Martian surface in 1976. Since then, other spacecraft have confirmed the presence of the compounds. The 2009 Phoenix lander found that perchlorates make up between 0.4 and 0.6 percent of the soil sample it collected.

While perchlorates, which are composed of chlorine and oxygen, are toxic to humans, microbes typically love the stuff. And researchers have been optimistic that their presence could support bacterial life on Mars. Some bacteria on Earth use naturally occurring perchlorate as an energy source.
The compound also lowers the melting point of water, which could improve the chance of liquid water existing on the Red Planet. But the latest study, published in the journal Scientific Reports, suggests that in the presence of ultraviolet light perchlorate is not so microbe-friendly.

Mars has a thin atmosphere, which often leaves its surface bathed in UV rays. And when heated, chlorine-based molecules like perchlorates cause heavy damage to living cells.

“We knew before that any life would have an incredibly hard time to survive on the surface, and this study experimentally confirms that,” Dirk Schulze-Makuch, an astrobiologist at Washington State University not involved in the study.
mars surface
It’s also possible that hypothetical Martian bacteria could be much tougher than the common Bacillus subtilis. On Earth, researchers have found all types of extremophile organisms with the ability to survive under intense heat and pressure, in the presence of acid, without water and even inside rocks.
“Life can survive very extreme environments,”  says co-author Jennifer Wadsworth .“The bacterial model we tested wasn’t an extremophile so it’s not out of the question that hardier life forms would find a way to survive.”
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Scientists Accidentally Produce An Enzyme That Devours Plastic

There are research teams around the world dedicated to finding a remedy for the growing plastic pollution crisis, but now it seems that one group of scientists have found a feasible answer — and they stumbled upon it by accident.

Researchers studying a newly-discovered bacterium found that with a few tweaks, the bug can be turned into a mutant enzyme that starts eating plastic in a matter of days, compared to the centuries it takes for plastic to break down in the ocean.

The surprise discovery was made when scientists began investigating the structure of a bacterium found in a waste dump in Japan.

The bug produced an enzyme, which the team studied using the Diamond Light Source, an intense beam of X-rays 10 billion times brighter than the sun.

At first, the enzyme looked similar to one evolved by many kinds of bacteria to break down cutin, a natural polymer used by plants as a protective layer.

But after some gentle manipulation, the team actually improved its ability to eat PET (polyethylene terephthalate), the type of plastic used in drinks bottles.

Existing examples of industrial enzymes, such as those used in detergents and biofuels, have been manipulated to work up to 1,000 times faster in just a few years.

McGeehan believes the same could be possible with the new enzyme: “It gives us scope to use all the technology used in other enzyme development for years and years and make a super-fast enzyme.

According to the team, potential future uses for the enzyme could include spraying it on the huge islands of floating plastic in oceans to break down the material.

Plastic pollution has seen renewed focus in recent times, thanks largely to attention drawn by David Attenborough’s Blue Planet II series, and through a number of legislative proposals.

Science has examined a huge range of solutions, from plastic-plucking robots to infrared identification from space, but the discovery of this mutant enzyme could herald an entirely new way of dealing with the issue.

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To Get Humans To Mars, Making Space Food With Space Poop Is What We Need


Astronauts aboard the ISS drink recycled pee for a reason: we can only bring so much food and water to to space. Imagine how much more we need to take for that year-long journey to Mars.

Since bringing more resources means higher costs — the heavier a spacecraft is, the more fuel it needs, after all — scientists are looking to find ways to make self-sustaining vehicles.

A team of researchers from Penn State University, for instance, have developed a method to make space food with astronaut poop.

Disgusting? Well, the team’s technique doesn’t exactly turn the feces itself into food.

Instead, it uses microbes to break down solid and liquid human waste with anaerobic digestion, a process that doesn’t consume precious oxygen, similar to what happens inside our stomach when we eat.

During digestion, the fecal material produces methane, which is then fed to bacteria (Methylococcus capsulatus) naturally found in soil and already used to make animal pellets using a microbial reactor.

When the researchers tested their technique using artificial poop, the end result was biomass that’s 52 percent protein and 36 percent fats.

That’s what future spacefarers would eat — and what Mark Watney probably would’ve used as dip for his potatoes if he just had the equipment.

Team leader and Penn State professor Christopher House admits that “it’s a little strange,” but it’s like “Marmite or Vegemite where you’re eating a smear of ‘microbial goo.‘” We’ll bet space-poop goo is also an acquired taste.

In addition to being packed with nutrients, the goo is also relatively fast to make: researchers said they managed to remove 49 to 59 percent of the solids in the waste material within 13 hours during their tests.

That’s much faster than current waste management treatment methods, and as House said, it’s “faster than growing tomatoes or potatoes.

The researchers also found potential food sources other than Methylococcus capsulatus during their tests.

When they tried growing microbes in either an alkaline or a high-heat environment to prevent the growth of pathogens, they discovered that a bacterium called Halomonas desiderata (15 percent protein and 7 percent fats) can thrive in the harsh conditions.

Another species of bacteria called Thermus aquaticus can live in environments reaching 158 degrees Fahrenheit, as well.

With a nutritional value that’s 61 percent protein and 16 percent fats, it’s yet another possible source of microbial goo grub for future astronauts.

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Is Hand Sanitizer Killing You?

Parents have made an enemy of bacteria for years. They’ve sanitized tabletops, disinfected playthings and wiped down grocery store carts to keep their children safe from unseen germs.

That instinct is a natural one, experts say, but emerging research about the body’s bacteria, fungi and other cells that cover our skin, gastrointestinal tract and other areas suggests that we may be taking hygiene vigilance a little too far.

That, in the long run, weakens our immune systems.

Scientists are only beginning to understand the millions of microbes that make up the human microbiome, said UC Davis microbiologist Jonathan Eisen, but researchers are finding that antibiotics.

Household disinfectants and other sanitizing products are also killing the “good bacteria” that help our bodies fend off disease.

Many believe that the shortage of certain microbes explains recent spikes in childhood allergies and asthma.

People in developing countries, who grow up in less sterile environments, eat mostly non-processed foods and spend more time around people and animals, have more varieties of microbes in their gastrointestinal tracts than people in the United States, recent studies show.

At the same time, food allergy rates are lower in Africa and South America than in North America, Western Europe and Australia, according to the World Allergy Organization.

The findings play into the “hygiene hypothesis,” or the idea that childhood infections acquired through unhygienic contact bolster the immune system against disease later in life.

Of course, too many germs can also carry risks for children, said Dr. Ralph Morris, a Minnesota physician.

So what is the microbiome anyway?

The microbiome is made up of trillions of bacterial cells that we pick up from the world. They’re mostly concentrated in the gastrointestinal tract, but they also live in the lungs, mouth and other parts of the body.

Microbes assist in food digestion and trigger the immune system to fight illness. Some microbes appear to contribute to weight gain and others cause inflammation.

A difference in microbial makeup can predispose people to certain diseases or change the way they react to drug therapies.


How is it formed?

Germ exposure starts in utero and keeps forming through adulthood, making the first few months and years of a child’s life a crucial time for building a healthy microbiome.

Many experts, including Roseville allergist and immunologist Dr. Travis Miller, believe the ways babies are delivered help determine their future health.

Babies born vaginally take in healthy microbes from the birth canal, organisms that babies delivered by cesarean section don’t pick up, Miller said.

That may place C-section babies at a disadvantage from the get-go, he said.

How dirty is dangerous?

Land Park mother Amanda Bauer said she tries to be careful about keeping her two young daughters clean.

She doesn’t carry hand sanitizer around with her, she said, but always makes sure her 7- and 9-year-olds wash their hands after going to the grocery store.

Around the house, she cleans off door handles, remote controls and other heavily touched items with Lysol wipes, especially when someone is sick.

Recent science supports Bauer’s beliefs.

A study from Swedish researchers found that children whose families washed dishes by hand had significantly lower rates of eczema and slightly lower rates of allergies than children whose families used a dishwasher.

Other studies have shown children who live with dogs and cats tend to be healthier because the pets pass on their own beneficial microbes.

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Bacteria On Space Station Likely From Germy Humans, Not Aliens

Living bacteria have been found on the outside of the International Space Station, a Russian cosmonaut told the state news agency TASS this week.

Anton Shkaplerov, who will lead Russia’s ISS crew in December, said that previous cosmonauts swabbed the station’s Russian segment during spacewalks and sent the samples back to Earth.

The samples came from places on the station that had accumulated fuel waste, as well as other obscure nooks and crannies.

Their tests showed that the swabs held types of bacteria that were not on the module when it originally launched into orbit, Shkaplerov says.

In his interview with TASS, Shkaplerov says the bacteria “have come from outer space and settled along the external surface“, a claim that sparked some media outlets to issue frenzied reports about aliens colonizing the space station.

For now, though, details about the swabbing experiment are thin on the ground.

Shkaplerov did not note whether the study has been vetted by a peer-reviewed journal, which means it’s unclear exactly when and how the full experiment was conducted, or how the team avoided any contamination from much more mundane bacteria on the cosmonauts or in the Earth-bound lab.

Interview requests with the Russian space agency were unanswered when this article went to press. Up in the vacuum of space, microbes have to deal with turbulent temperatures, cosmic radiation, and ultraviolet light.

But Earth is home to plenty of hardy organisms that can survive in extreme environments, like virtually indestructible tardigrades.

Sometimes, researchers intentionally send terrestrial contaminants, such as E. coli and rocks covered in bacteria, into space to see how it will react.

And TASS reports that on a previous ISS mission, bacteria accidentally hitched a ride to the station on tablet PCs and other materials.

Scientists sent these objects up to see how they would fare in space, and the freeriding organisms managed to infiltrate the outside of the station.

They remained there for three years, braving temperatures fluctuating between -150 and 150 degrees Celsius.


These types of discoveries present concerns for scientists trying to limit the spread of human germs on other worlds.

NASA in particular has set strict limits on its interplanetary contamination.

Apollo astronauts were quarantined when they returned from their missions, for example, to prevent extraterrestrial germs from making their way out into the world.

And almost all equipment from Earth is sterilized before it heads skyward, either with extreme heat or an alcohol bath, depending on its intended destination.

These treatments are especially important for missions sent to Mars, which may have once hosted its own life-forms, leaving fossil traces in the rusty rocks.

But all bets may be off when and if we manage to send humans to explore Mars, writes The Planetary Society’s Emily Lakdawalla: “Once we’ve put humans on the surface, alive or dead, it becomes much, much harder to identify native Martian life.”

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According To A Russian Cosmonaut, Bacteria Found On International Space Station May Be Alien In Origin

Bacteria found on the outside of the International Space station could be alien life, according to a cosmonaut who has visited the satellite.

Spacewalkers regularly take samples and materials from the outside of the station when they head outside for what are officially called “extravehicular activity“.

Those samples are then taken down to scientists on Earth, who study them to understand the workings of the International Space Station and possibly life in space.

Now Anton Shkaplerov, a Russian cosmonaut who has served on board the space lab, told the Russian state news agency that one of those experiments had found something interesting.

Bacteria that had not been there during the launch of the ISS module were found on the swabs,” Mr Shkaplerov said. “So they have flown from somewhere in space and settled on the outside hull.

He made clear that “it seems, there is no danger “, and that scientists are doing more work to find out what they are.

He said also that similar missions had found bacteria that could survive temperatures between -150 degrees celsius and 150.

That bacteria appears to have made its way from Earth – but suggests that it can survive in the harsh environments of space.

It isn’t entirely clear where the rumoured organisms are currently being stored, and what scientists know about them.

Finding bacteria that came from somewhere other than Earth would be one of the biggest breakthroughs in the history of science – but much more must be done before such a claim is made.

Earlier this year, Russian scientists announced that the “Test” experiments had found a range of different organisms that had been brought up from Earth and seemed to be surviving by clinging onto the ISS’s hull.

They included plankton and bacteria that had been pulled up by a phenomenon that lifts micro-organisms up into the heights of the atmosphere.

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Possible Side Effects of the Bread & Water Diet

Many weight loss plans like carbohydrate cycling, ketogenic diets, liquid diets can be complicated, so a diet of bread and water alone may seem attractive due to its simplicity.

While such a diet may produce weight loss due to a low calorie content, there are many potential side effects, as a bread and water diet would not provide balanced nutrition.

Consult a doctor and apply your own common sense before you start any diet plan. Here are some side effects of bread and water diet:

  1. Reduced Testosterone Levels
    The foods you eat not only have an effect on your weight, but the functioning of your body’s internal systems, including your endocrine system, which controls hormone production.Bread contains very little fat and tends to be rich in fiber, so a diet comprised entirely of bread and water could have negative effects on your hormone levels.According to research published in the December 1996 issue of “The American Journal of Clinical Nutrition“, consuming a diet rich in fiber and low in fat can decrease levels of testosterone. This hormone helps produce muscle and can aid in fat loss.
  2. Impaired Wound Healing
    Although bread does provide some important nutrients, it is typically devoid of vitamin C. This nutrient acts as an antioxidant and is crucial for healthy growth and development.Additionally, vitamin C plays a vital role in the wound healing process, so a bread and water diet may compromise your body’s ability to heal injuries.
  3. Eye Damage
    Consuming a diet consisting of just water and bread can also impair your vision. This is because neither water nor bread provide vitamin A.This vitamin is important for a wide array of functions, including maintaining the lining of your eyes that keeps out harmful bacteria.You may also experience night blindness, as a lack of vitamin A can dry out your eyes and cause damage to your cornea and retina.
  4. Increased Risk of Infection
    Consuming just bread and water may make you more susceptible to infections. This is because both vitamins A and C, vitamins not provided by bread — are involved in maintaining the integrity of your immune system.Even relatively innocuous infections may become serious health problems due to your compromised ability to fight off infections.
  5. Weak Bones
    Eating a diet of just bread and water can be detrimental for your skeletal system. This is because vitamin C helps produce collagen, which forms part of your bone structure.Additionally, bread contains no vitamin D, and low levels of this vitamin may lead to osteoporosis.
  6. Poor Skin and Hair Health
    Neither bread nor water are rich in dietary fat. While dietary fat is sometimes avoided on diets because it is high in calories, doing so can be detrimental.Your body needs fat to maintain your skin and hair health, so a diet low in fat can be detrimental for both.

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NASA Plans To Use Bacteria And Algae To Make Oxygen On Mars

If humans land on Mars in the 2030s as planned, one thing that will be essential to their survival will be self-sufficiency, as they won’t be able to take too much cargo with them.

With this in mind Nasa is testing whether oxygen can be created from Martian soil, without having to carry it all the way from Earth.

The innovative method would see bacteria or algae use the soil as fuel, pumping out usable oxygen in the process for astronauts on the surface.

Nasa has been working with Techshot Inc of Greenville, Indiana to develop this method in a so-called ‘Mars room’, which mimics the conditions on the red planet.

It is able to simulate the atmospheric pressure on the planet, in addition to the day-night temperature changes and the solar radiation that hits the surface.

In experiments, certain organisms were capable of producing oxygen from Martian soil – known as regolith – and they also removed nitrogen from it.

This is a possible way to support a human mission to Mars, producing oxygen without having to send heavy gas canisters,” said Eugene Boland, chief scientist at Techshot.

The research is part of the Nasa Innovative Advanced Concepts (NIAC) Programme.

It’s envisioned that biodomes could be scattered across the surface to produce the oxygen needed for humans to survive.

The oxygen produced could also be stored for later use.

But while experiments on Earth are all well and good, the scientists want to test their method actually on Mars in the near future.

To do so, an upcoming rover – such as the 2020 Mars rover – could carry small container-like devices with Earth organisms inside.

The containers would be buried a few inches underground in certain locations, to see how successful they are at producing oxygen.

Sensors inside the container would detect how much oxygen was made, and report the findings back to a satellite in Mars orbit.

The scientists note that the container would be sealed tightly, to prevent the organisms being exposed to – and possibly contaminating – the Martian surface.

But if proven successful, future explorers on Mars may use multiple biodomes like this to produce the oxygen they need to survive.

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Engineering Mosquito Gut Bacteria To Fight Malaria

A malarial mosquito is a flying factory for Plasmodium – a parasite that fills its guts, and storms the blood of every person it bites. By hosting and spreading these parasites, mosquitoes kill 1.2 million people every year.

But Plasmodium isn’t the only thing living inside a mosquito’s guts. Just as our bowels are home to trillions of bacteria, mosquitoes also carry their own microscopic menageries.

Now, Sibao Wang from Johns Hopkins Bloomberg School of Public Health has transformed one of these bacterial associates into the latest recruit in our war against malaria.

By loading it with genes that destroy malarial parasites, Wang has turned the friend of our enemy into our friend.

Many groups of scientists have tried to beat malaria by genetically modifying the species of mosquito that carries it – Anopheles gambiae.

Marcelo Jacobs-Lorena, who led Wang’s new study, has been at the forefront of these efforts. In 2002, his team loaded mosquitoes with a modified gene so that their guts produce a substance that kills off Plasmodium.

The approach worked very well in the laboratory,” says Jacobs-Lorena, but it would be impossible to load wild mosquitoes with the anti-malarial gene.

Instead, you’d have to ensure that the modified mosquitoes could out-compete their wild peers, so that the gene passes from one generation to the next via natural breeding.

It must also do so quickly before the parasite can evolve a countermeasure.

That’s very difficult to guarantee, especially given our limited understanding of the mating habits and ecology of mosquitoes.

Jacobs-Lorena found an alternative. He would sneak the Plasmodium-killing gene into the bacteria that live inside a mosquito’s guts, rather than the insect’s own genome.

We thought that it would be easier to introduce bacteria than genes into mosquitoes in the field,” he says.

The strategy has one big advantage: the gut is the most vulnerable part of Plasmodium’s complicated shape-shifting life cycle.

When the mosquito bites an infected human, it sucks up thousands of Plasmodium sex cells, which mate with each other to form fertilised eggs called ookinetes.

These invade the lining of the insect’s gut and become factories called oocysts. Each one manufactures thousands of long, worm-like sporozoites that swim into the mosquito’s salivary glands, ready to jump into a new person.

The oocyst stage is the bottleneck in this process. Even if a mosquito swallows thousands of Plasmodium cells, it typically ends up with far fewer oocysts in its gut.

In such small numbers, they make an attractive target, and it just so happens that the gut contains potential collaborators – bacteria.

Pantoea agglomerans is among the most common of these partners. It’s co-exists harmlessly with the mosquito and we still don’t know what, if any, role it performs.

Wang, a member of Jacobs-Lorena’s team, engineered P.agglomerans to make several proteins that turn the mosquito’s gut into a hostile zone for Plasmodium.

Some of these proteins interact the mosquito’s gut to prevent the young Plasmodium parasites from invading it, while others (including one derived from scorpion venom) tear the parasite apart.

The bacteria secrete these weapons into the gut where they get to work upon any invading Plasmodium.

It also helps that when a mosquito drinks blood, the numbers of P.agglomerans within it shoot up by over 100 times, creating a defence force that’s ready for the incoming parasites.

Wang found that the engineered bacteria slashed the numbers of oocysts in mosquitoes by 85 to 98 per cent.

Just 14 to 18 per cent of the insects carrying the defensive microbes became infected with Plasmodium after drinking contaminated blood, down from a typical proportion of 90 per cent.

Scientists who are trying to use GM-mosquitoes to fight dengue fever in Brazil and the US have already encountered severe hostility. The bacterial approach might fare even worse.

It relies on a GM bacterium which can’t be contained once released in mosquito populations, and will easily end up in the food chain and eventually also on peoples plates,” says Dimopoulos.

While such bacteria may not pose a hazard to humans and animals, the work required to prove, educate and finally convince various stakeholders that the implementation is safe will be lengthy and challenging.”

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Infection During Pregnancy May Alter Expression Of Autism Genes

A severe infection during pregnancy disrupts the expression of autism genes in the child, a study in rats suggests.

The findings may help to explain why maternal infections boost autism risk by as much as 37 percent.

Infections set off an immune reaction involving molecules that can enter the womb.

The new work shows that infection in a pregnant rat dampens or boosts the expression of a number of genes linked to autism.

Many of these genes control the growth and formation of the junctions between neurons, called synapses. And some are on a list of genes that harbor rare, harmful mutations in some individuals with autism.

It’s amazing what the correspondences are” between findings in rats and those in children with autism, says Eric Courchesne, professor of neuroscience at the University of California, San Diego, who was the senior collaborator on the study.

Even though there may be different causes behind autism, these different causes seem to converge to common attributes.”

Environmental factors such as maternal infection sometimes exacerbate the effect of genetic risk factors for autism.

For example, a 2015 study revealed that children who have a large DNA deletion or duplication linked to autism and whose mothers had infections during pregnancy have more severe autism features than children with only one of these risk factors.

The new work shows how the prenatal environment may affect autism genes to alter brain development, says Melissa Bauman, associate professor of psychiatry and behavioral sciences at the University of California.

Courchesne and his colleagues used gene expression data from a 2012 study.

In that study, researchers injected pregnant rats with a chemical called lipopolysaccharide, which mimics a bacterial infection and elicits a strong immune response.

Rat pups exposed to an immune response in the womb are known to show autism-like features, such as social deficits.

In the 2012 study, researchers injected the rats on day 15 of pregnancy, equivalent to the end of the first trimester in people.

Four hours after the treatment, they collected the fetal brain tissue to determine which genes were expressed and at what levels.

In the new work, Courchesne team reanalzyed this dataset to confirm previous results and found that the pups express 4,033 genes at unusually high levels.

These genes seem to play a role early brain development, guiding processes such as cell division.

The pups also show diminished expression 4,959 genes that help guide the formation of neurons and synapses.

The study represents a step forward in understanding how maternal infection might boost autism risk, says Alan Brown, professor of psychiatry and epidemiology at Columbia University, who was not involved in the study.

The findings indeed overlap with several genes and mechanistic pathways that have been suggested in autism,” says Brown.

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