On April 8th, 2018 we learned about

Investigating the likelyhood of microbial life existing in Venus’ upper atmosphere

You don’t want to live on Venus, but there are a lot of places you don’t want to live on Earth as well. Hydrothermal vents, acidic lakes and the cold reaches of the upper atmosphere are all pretty inhospitable plants and animals alike, but that doesn’t mean that they’re not home to life. As we look closer at the nastiest, hottest, most acidic bits of real estate on the planet, the more bacteria we find adapted to these extreme conditions. This has scientists excited, because if life is in the market for these spots on Earth, there’s a small but real chance that it might love what’s available on Venus.

Too hostile to be a home?

Don’t feel bad if you’re not familiar with the brutal conditions on Venus. It’s such a rough part of the solar system that the probes we’ve sent to the second planet generally don’t last very long; the Soviet Venera 13 set records by surviving for a whole 127 minutes. Aside from a few photographs, we have been able to determine that the surface of Venus gets up to 863º Fahrenheit, and the air pressure is between 17 to 20 times as strong as on Earth. With the wind and acidic chemistry in the air, even the heartiest Earth-born bacteria couldn’t survive on Venus’ surface. On the other hand, the upper atmosphere may be just gentle enough to allow microbes a small chance at survival.

The upper layers of clouds on Venus are reflective and acidic, made mostly of carbon dioxide, water and sulfuric acid. It doesn’t sound pleasant, but the temperatures are low enough that life as we know it could exist there. What’s more, the sulfuric acid may even be a byproduct of microbial metabolisms– species on Earth are already known to do that (often with unfortunate consequences for their surroundings.) What’s more, observations from space have noted unexplained dark patches in these Venusian clouds, most of which are within the size range of bacteria on our own planet. This isn’t proof of alien life, but since we’ve never tested specifically for organic chemistry in Venus’ upper atmosphere, we can’t rule out the possibility of microbes without getting more information.

While spacecraft are circling Venus in space, none of them are in a position to sample these dark spots in the planet’s clouds. One proposed design is the Venus Atmospheric Maneuverable Platform (VAMP), which would fly through caustic clouds for as long as a year. With the right set of sensors, like mass spectrometers and microscopes to examine airborne samples, researchers would be in a better position to identify potentially organic materials in the atmosphere.

Originating from the past, or other planets

As hard as it is to picture life on such a harsh planet, there are actually a few possibilities for how bacteria could end up there. The first option is that the bacteria migrated from the ground, since Venus was probably a nice place 2.9 billion years ago. At that time, there’s a fair chance that the planet was a tepid 51° Fahrenheit on the surface, giving microbes a chance to evolve before the upper atmosphere was the only place left to go. Alternatively, the clouds could have been seeded by a place like Earth, as high-speed dust moving through the solar system has been calculated to be able to knock microbes in our atmosphere clear into space. So if life didn’t arise on Venus on its own, there’s still a chance that other Earthlings simply beat us to the punch of traveling to another planet.

Source: Is there life adrift in the clouds of Venus? by University of Wisconsin-Madison, Science Daily

On March 27th, 2018 we learned about

Reshaping sugar crystals to reduce quantities while staying sweet

The average piece of milk chocolate is 60 percent sugar by weight. While your stomach and pancreas will need to process all those calories, there’s a chance that the bundles of sugar-sensitive cells on your tongue won’t actually taste it all. This has presented a bit of an opportunity for food scientists looking for ways to reduce the amount of sugar used in sweet foods, as they realized that less sugar can be used if more of that sugar will actually be tasted when you eat. So rather than add sugar substitutes like aspartame, researchers at Nestlé and startup DouxMatok have been trying to reshape the sugar itself so that it’s essentially easier to enjoy, even in smaller doses.

Creating more contact with our taste buds

Nestlé’s approach has been to make what they’re calling “structured sugar.” Using a process that involves spraying sugar, milk and water in warm air, they’re creating porous sugar crystals that dissolve faster than more cubic crystals. This allows more of the key molecules in the sugar to quickly trigger your taste buds, giving you the equivalent experience of eating a sweeter food. By maximizing how much you experience each gram of sugar, Nestle says they’ll be able to cut just how much sugar goes into their recipes by as much as 30 percent, starting with their new Milkybar Wowsomes in the United Kingdom.

DouxMatok’s patented sugar operates on a similar principle. Instead of increasing your tongue’s contact with sugar crystals by making them hollow and porous, their process increases the available surface area of sugar crystals by attaching them to a carrier agent that will help them come in contact with the correct tongue cells. Again, this allows for your tongue to come in contact with more of each gram of sugar, allowing less to be used in a recipe overall.

Selling the public on smaller sizes

Even if both high-surface area sugars keep treats sweet, candy makers are concerned with the dimensions of their product on a larger scale as well. Going back to our original piece of milk chocolate, a 30 percent reduction in sugar will likely result in a noticeable decrease in the candy’s net weight. There’s concern that this may look bad to consumers, and that some new filler agent will be needed to make up the difference.

One option may be just to reshape the chocolate itself. When people were asked to let chocolate pieces melt in their mouths, manufacturers found that spheres were considered the tastiest shape. It’s suspected that a round shape allows air to circulate through the mouth, which makes it easier to smell the compounds that help give chocolate its flavor (aside from all that sugar, of course.)

Source: Designer sugar is here – but just what are we sacrificing for healthier sweets? by Jodi Helmer, The Guardian

On March 25th, 2018 we learned about

Biologists rely on dogs’ sense of smell to find samples of endangered animals’ feces

Dogs’ sense of smell is legendary, possibly on par with their revolting interest in other animal’s poop. Biologists have realized that these two strengths are quite complimentary, although the dogs don’t get to eat any of the feces that they help find. Instead, the stinky samples are collected an analyzed to assess the health of whichever animal made them. As dogs would surely tell us, there’s a lot of information in poop if you know what you’re sniffing for.

There are currently 17 dogs working for the CK-9 program at the University of Washington Center for Conservation Biology, all of whom have trained to turn their nose into a focused, feces-finding instrument of science. They start on controlled course, where they can be rewarded for finding and reporting poop from specific species, such as spotted owls or caribou. Over time, a dog may train on as many as 13 different species, helping biologists gather data on the state of threatened or endangered animals in need of protection. By analyzing found poop, researchers can figure out an individual’s identity, stress levels and more, all without needing to actually capture any of them.

Sniffing scat on the high seas

Most of this work is conducted on land, but some dogs even work on boats to find whale droppings. Or floatings? Whale poop is often brightly colored and floats on the water’s surface when first released, making it practical to sample if it can be found quickly enough. While a human nose is capable of detecting whale poop, a dog can pick the scent up from a mile away, giving their handler signals about which way the boat needs to go. It has enabled biologists to successfully patrol 100 square miles of territory, keeping tabs on individual whales each year. For example, researchers are currently tracking the levels of toxins from orcas eating Chinook salmon, as it may be influencing whale birthrates around the Pacific Northwest.

Finding feces to play fetch

As much as your dog may be interested in sniffing stool that they find on their evening walk, the C-K9 dogs do still need motivation to stay focused on their task. Instead of food, each successful sample is rewarded with a bit of playtime with a rubber ball. Even on a boat, a short round of fetch is used to keep these dogs going. That may not be a huge motivation for every dog out there, so an intense desire to play fetch is actually the key perquisite to join the C-K9 team. Once properly motivated, it seems that any pooch is capable of finding particular bits of poop.

Source: Meet the Dogs Sniffing Out Whale Poop for Science by Michelle Z. Donahue, Smithsonian

On March 18th, 2018 we learned about

Platypus milk fights bacteria with specially-folded proteins

When you’re as weird a mammal as a platypus, some compromises are to be expected. As monotremes, platypuses hatch their kids out of eggs instead of giving live birth, although mammals don’t really have a monopoly on that bit of child-rearing in the first place. Platypuses do try to stick with the signature mammalian ability to feed milk to their offspring, even if they lack the lips or nipples to make feeding time a tidy process. This kind of milk secretion has required its own set of adaptations, and one of them may prove to be very helpful to humans, regardless of how we nurse.

When a platypus feeds her young, it does so by secreting the milk through special patches of skin around her belly. That milk dribbles into grooves in the mother’s skin where it can be more easily lapped up, or saturate her fur where babies can suckle. The potential complications in this path means that the milk needs extra protection from bacteria who might hitch a ride into the baby’s mouth, and researchers now believe they’ve gotten a handle on the protein responsible.

The protein itself isn’t as exciting as the way it functions. Researchers from Australia’s Commonwealth Scientific and Industrial Research Organization (CSIRO) isolated the protein, then rebuilt it in the lab to more closely observe how it worked. The way the protein folds into a series of curly loops that not only helps fend off bacteria, but also earned it the nickname “Shirley Temple,” after the actress’ hair. If researchers can replicate those properties in other proteins, we can incorporate them into medicines without needing to specifically suck on monotreme stomach hair.

Antibiotics in other mammals’ milk

As special as these proteins are, platypuses aren’t the first mammal to load their milk with bacteria-fighting ingredients. Human milk can also fend off bacteria like Group B. Streptococcus, although we do it with sugars instead of proteins. Those sugars don’t seem to be produced equally by every mom, so researchers are now trying to figure out exactly how they work so their antibiotic properties can be added to more accessible media.

Source: Saving lives with platypus milk by CSIRO, Phys.org

On March 4th, 2018 we learned about

Resilient bacteria in Chilean desert raise hopes of finding microbes on Mars

Life as we know it needs water. Aside from the larger-scale functions we need water for, even bacteria struggle if their proteins unravel when no water is available. So when researchers in the found traces of bacteria and algae in the hyperarid Atacama Desert, it was assumed that these organisms were essentially unlucky. A place that can go years between rainfalls just can’t support life, and so these microbes and accompanying bits of DNA that turned up in soil samples were thought to have been blown in by the wind, and left to decompose among the rocks.

Dormant, but not dead

As it turned out, many of these parched organisms were just waiting for the rain. Soil samples were collected shortly after a rainfall in 2015, and found to be much more biologically active than anyone expected. Researchers were able to see that the microbes were healthy and reproducing, and had apparently only been dormant in the previous dry spell. It’s not an unprecedented survival strategy, as other organisms, such as tardigrades, are also known to become dormant in response to dehydration. However, the idea that these desert microbes essentially spend most of their existence waiting for the next drop of moisture shows that life is worth looking for in even the most extreme environments.

Red Planet proxy

The reason anyone was looking in Atacama in the first place is thanks to its resemblance to another extreme environment that may also be home to dormant organisms. The minimal rainfall and rocky terrain has made the Chilean desert a proxy for the surface of Mars here on Earth. Sure, there’s a lot more oxygen, not as much radiation from the Sun, etc. in Chile, but it’s the closest approximation of our neighboring planet available. As such, it’s been used to test equipment bound for Mars, and in this case, see if there was any hope of finding living things in hyperarid conditions. After all, if nothing could survive in Atacama, the colder and even drier Martian landscape would be an impossible place for any organism to survive.

Instead, it looks like there’s a definite chance that the harsh conditions of Mars could be home to at least dormant microbes. The Red Planet was once wetter and warmer than it is today, and thus more likely to be home to at least microbial organisms like bacteria. As the planet lost much of its atmosphere and grew colder and drier, some of those microbes could have adopted a similar strategy to what was found in Atacama— going dormant until the next round of moisture arrives. Instead of rain, that would most likely be some kind of frost or snow, or possibly just some sub-surface run-off soaking through the Martian soil. It’s no guarantee that we’ll find any native Martian species, but it supports the idea that it’s still worth looking.

Temporarily full of flowers

Funnily enough, the rains can sometimes bring even more than microbes in Atacama. Unusual rainfall in the fall of 2017 actually spurred the growth of flowers and various plants. While it was a lovely sight for tourists, it wasn’t exactly what Mars researchers would want for their investigations.

Source: Life in world's driest desert seen as sign of potential life on Mars by Washington State University, Phys.org

On January 18th, 2018 we learned about

Updating our spotty, rat-filled understanding of the 14th century plague epidemics

If there’s one thing we can learn from the Black Death in the 14th century, it’s the importance of record keeping in times of crisis. Granted, it was probably hard to focus on documenting what was going on when tens of millions of people were dropping dead for no obvious reason. However, piecing together exactly how the plague spread with the speed it did has been an ongoing question, even long after we’ve come to understand and successfully treat the Yersinia pestis bacteria that actually causes bubonic plague. While rats have long been thought to have carried fleas that carried the bacteria, new investigations are starting to cast doubt on what we thought we knew about these horrifying epidemics.

No rats required

To be clear, Y. pestis is still the cause of death that killed millions of Europeans on more than one occasion. The question is how big a role rats played in transmitting the bacteria to humans. Part of our evidence against the rodents is that they have often play a role in plague outbreaks today, which understandably makes a strong case for their guilt in the 14th century. However, there are some holes in the story of past epidemics, such as no reporting on dead rats turning up in large numbers (as the rodents can be killed by the plague just as we can.) Researchers have also questioned if the flow of infections that we do know about really required rats’ presence in the first place, so they ran some tests to find out.

These experiments obviously didn’t involve risking any human or rat lives. They were conducted as simulations in a computer, allowing changes in different variables to be run over and over, eventually revealing the likelihood of one scenario over another. Obviously, long-shots can still happen, but these simulations showed that fleas biting humans could be passed around quite efficiently with no help from furry friends. In fact, in seven out of nine cities’ virtual infections, the human-flea-human model was a better match for mortality records than scenarios that depended on the movement of rodents.

Looking at leprosy

While these simulations have tried to consider an array of data sources to build a more accurate picture of how the plague spread, some historical gaps have been filled erroneously. Many images that are now archived as contemporary depictions of plague victims are actually pictures of other diseases entirely, such as leprosy. This kind of mistake has become common enough that it’s likely reshaping people’s understanding of what symptoms the bubonic plague actually produces.

Medieval images of leprosy, later labeled as the plague, often include eye-catching lesions on the victims’ skin. It’s dramatic and easily understood as a sign of disease, making these mislabeled images all the more convince to audiences lucky enough to never encounter an actual bubo- the real calling card of the bubonic plague. While some victims could occasionally end up with dark red spots under their skin, most people would end up with a single swollen lymph node in the armpit or neck, depending on where the bacteria-carrying flea bit them. However, these buboes don’t turn up in any drawings or paintings from the 14th century outbreaks. Instead of showing the medical reality of the plague, the few contemporary images directly related to the epidemic focus on its effect on societies, such as a drawing of people burying coffins from 1349, or Jews being burned alive in the 1340s after they were blamed for the disease.

Seeing patterns in the symptoms

Even after the dramatic epidemic of the 14th century, the plague revisited Europe every few decades. Bit by bit, people started to put the pieces together, even making a point to record what an actual plague victim looked like. Images of swollen lymph nodes are directly connected to the plague in imagery from the 15th century, both in artwork and medical documents, some of which suggested lancing buboes to save infected patients.

It’s understandable that people didn’t know what to keep track of before they even knew what was making them sick. But it’s interesting to consider how much information about a curable disease is still hard to be sure of. As someone who was preemptively treated for bubonic plague once as a toddler, I guess I’m just grateful that someone around me knew what to look for at a time when it counted. For what it’s worth, in that case people blamed a flea-bitten cat.

Source: Maybe Rats Aren't to Blame for the Black Death by Michael Greshko, National Geographic

On January 11th, 2018 we learned about

Mammals keep our offspring on our left side so we can more easily identify their emotions

By the time my son was two-years-old, my left tricep was in great shape. Neither of my kids are petite, and they both loved to be carried around, giving my arms and shoulders plenty of exercise. Being right-handed, I tried to keep the kids perched on my left arm most of the time, leaving my “good” hand to interact with the rest of the world. There may have been a more tender side to this preference though, as researchers are building the case that the left-arm bias may have actually been about accommodating the right side of my brain, not my hand.

Looking closely from the left

According to this study, the key reason to hold a baby in your left arm is so their face will be more clearly visible to your left eye. That eye is connected to the right hemisphere of your brain, which is more directly associated with processing spatial and emotional information. You probably don’t notice any that gap in your day to day activity, but most of the stimuli you’re looking at isn’t being clutched right next to your face (and pulling on your glasses). So by picking up small changes in your baby’s emotional state more easily, a parent can either head off trouble or just provide emotional feedback a bit faster.

Now even if parents have been proven to more accurately assess their babies’ moods when relying on their left eye, that doesn’t prove that emotional communication is the root cause behind this pattern. Maybe our right hemispheres became attuned to facial expressions because so many of us were already right-handed, and needed to access the ancient equivalent of a cell-phone all day? To test this, researchers looked at other mammalian parents to see if they had a similar preference in how they viewed their kids. Non-primates in particular were of interest, as their forelimbs should make less of a difference in how they interact with their offspring.

Gauging the maternal gaze of bats and walruses

The two other mammal species didn’t have much in common, except for the fact that they were known to spend some time looking at the faces of their offspring. Walruses and flying fox fruit bats were both observed interacting with their young, and as expected, they were more likely to orient themselves to keep their kin in their left visual field. In the case of the walruses, researchers noted that interactions from the animals’ left side weren’t only more common, but they lasted longer than engagement from the right.

In all of these cases, this pattern turned up in the babies as well. Offspring tended to approach their parents from the left, and when facing a parent could watch with their left eyes, just like their mothers.

Looking and leaning when kissing

Looking back to humans, a separate study may have inadvertently found a similar connection between adult humans. Adult couples were asked to kiss their spouse, and then record their descriptions of how the kiss occurred. Among other trends, researchers found that most people prefer to avoid mirroring their partner’s head position, and will tilt their head in the opposite direction, usually to each person’s right.

This was attributed to the handedness of each participant, and who initiated the kiss (usually men in heterosexual couples.) However, it seems like the tension between handedness and emotional observation is relevant here, because tilting your head to the right means that you’re giving your left eye the best view of your partner’s face. It seems fair to say that reading the emotional state of the person you’re about to kiss would be important, giving people all the more reason to lean right as they smooch. Unfortunately, this study didn’t specifically mention how often folks were kissing with their eyes open or closed.

Source: Mammals prefer to cradle babies on the left, study demonstrates by Nicola Davis, The Guardian

On January 4th, 2018 we learned about

Fossilized microbes show surprising biodiversity from 3.4 billion years ago

Most rocks on the Earth’s surface don’t last more than 200 million years before erosion or other forces get the best of them. Sure, that’s older than any dinosaur, but it’s only a tiny slice of our planet’s 4.5-billion-year history. Thankfully, rocks and crystals from the Earth’s early days do turn up here and there, helping us understand what our planet once looked like, and even more intriguing, who first called it home. That latter point is being revealed by 3.4-billion-year-old rocks from Australia, which have been found to not only contain fossilized microorganisms, but evidence of a surprisingly diverse ecosystem at a time when our planet was just beginning to be habitable.

Combing through fossils for traces of chemistry

The fossilized microorganisms weren’t multicellular animals of course, so these ancient rocks offered no bones or organs to study. Instead, researchers studied each singled-celled organism with secondary ion mass spectroscopy (SIMS). This technology allowed researchers to compare variations of carbon atoms, or isotopes, in the fossils and surrounding stone. The ratios of carbon-12 to carbon-13 was then be used to determine how each microbe functioned when it was alive, as those isotopes will accumulate differently in different metabolic conditions.

Differences in these early prokaryotes‘ metabolisms suggest that even 3.4 billion years ago, life had evolved a few different ecological niches. One group was apparently a methane producer, while another powered its metabolism by consuming methane. A third fossil showed signs of primitive photosynthesis that, unlike today’s plants, didn’t produce oxygen (which would have been toxic to these organisms). A microbe from an earlier study rounds out the bunch, as it relied on sulfur as its primary food-source.

Is life less unusual than we assumed?

This version of Earth certainly wouldn’t be habitable by today’s standards, but it’s an amazing degree of sophistication for a planet that had probably only had solid ground for 600 million years. This suggests that either the Earth was intensely lucky at an early age, or that life may be a bit more tenacious than we once thought. If it’s the latter, researchers suspect that this aggressive microbial timeline may have played out on other planets as well. It wouldn’t mean that other planets have the same complex organisms we do here, but that getting some microbes growing in the first place isn’t such a long-shot.

Until we get probes out to places like Europa, Titan or Enceladus, the best location to find extraterrestrial microbes may be Mars. This wouldn’t be to find microbes alive today, but to look for traces of similar fossils from the days when Mars was likely a more habitable planet.


On January 2nd, 2018 we learned about

Mouse guts demonstrate the multi-generational impact of low-fiber diets on microbial diversity

The next time you’re in the grocery store, consider the idea that you’re not just shopping for yourself. In addition to the enjoyment and nutrients you might gain, what you eat also makes an impact on the multitudes of bacteria that live in your digestive tract. In addition to the nutritional needs of your microbiome, recent research has found that what you munch on might also make a difference in the guts of your children, as well as your grandchildren. So what are all these microbes interested in eating? Fiber, and lots of it.

Fiber isn’t easy for us to digest, at least not on our own. Unlike animals that have multiple stomachs to help break down tough bits of cellulose, dextrins or pectins, humans have to get what we can from dietary fiber in the first round of digestion. Fortunately, bacteria living in our guts can help with this, as they help break down fiber by targeting what are known as microbiota-accessible carbohydrates. By fermenting these carbs, the bacteria feed themselves, and make a bit of fuel that our bodies can reclaim as well. If that weren’t enough of an incentive, well-fed microbes have also been linked to lower rates of allergies, infections and autoimmune diseases.

Starving the microbiome in sterile mice

Researchers at Stanford University wanted to see how long a gut’s microbiome could last without its favorite foods, checking to see just how strict a diet these bacteria were on. This would be a difficult test to control in humans, so mice were raised in a sterile environment, and with no natural bacteria of their own. That way, the starting microbiome could be controlled by seeding the mice’s’ guts with bacteria laden feces from a healthy human. It doesn’t sound appealing, but it made for mice that could healthily digest meals without any problems.

After a few weeks of a healthy, high-fiber diet, half the mice were switched to meals lacking in fiber, which made a clear impact on their gut bacteria. Bacteria populations declined in 60 percent of the sampled species in just seven weeks. Unfortunately, putting giving those mice extra whole grains and veggies didn’t really undo the damage— returning to a high-fiber diet restored some bacterial diversity, but the mouse guts were still 33 percent more homogeneous than before.

This simplified gut ecology persisted, even in other mice. Researchers compared gut bacteria in multiple generations of mice, and continued to see the impact of even temporary low-fiber diets. Fourth-generation low-fiber mice showed 72 percent less microbial diversity, and could only recover five percent of their stunted microbiome when switched to a high-fiber diet. Aside from the loss of bacterial diversity, researchers also noted a decline in glycoside hydrolases, the proteins that bacteria use to help digest fiber in the first place.

Is your bacterial diversity doomed already?

It’s good to keep in mind that this study was in an unusually controlled environment with a small number of mice. It shouldn’t be taken as a perfect proxy for human digestion, as we generally get exposed to a variety of bacteria in our everyday life, and usually eat a wider variety of foods than mice do. So while the mice needed to be isolated from these factors in order to properly test the possible impact of food, the degree of isolation likely makes a difference. With that said, most Americans don’t eat their recommended helping of 25 grams of fiber a day, and so it probably couldn’t hurt to eat more fresh produce, beans and whole grains in our diets. We can’t say for sure if our great-great grandchildren will notice the effects, but we’ll probably feel better while we wait for them to be born.

Source: Low-fiber diets make gut microbes poop out by Bethany Brookshire, Scicurious

On December 13th, 2017 we learned about

Antarctic microbes scavenge their metabolic fuel from the air around them

On a planet where live evolved around access to water, living in a desert is a challenge. Plants and animals that call these arid locations home often require impressive adaptations, like thorns and thick skin, to make the most of the resources available. As impressive as any of those adaptations are, scientists recently discovered that microbes may be the true masters of inhospitable biomes, making their homes in the coldest, darkest desert on Earth— the Antarctic. The various bacteria living in the icy terrain not only contend with a lack of water, but very low levels of carbon in the soil and a lack of photosynthesis-powering sunlight for half the year. With all these common sources of nutrients missing, it almost seemed liked the microbes were magically pulling their sustenance out of thin air.

As it turns out, the microbes were doing exactly that. The most reliable source of carbon and energy in the Antarctic is apparently the air itself. The microbes have evolved mechanisms to harvest what they need from hydrogen and carbon monoxide circulating in the atmosphere. It’s obviously not the most robust way to spur growth, but it seems to be the primary source of nutrition and energy for the microbes growing in locations where no plant could even hope to live.

Applications beyond Antarctic bacteria

The surprising diet these bacteria live off of raises two new lines of inquiry. While scavenging the air itself doesn’t appear to be the most energy-rich way to live, understanding how the bacteria accomplish this task may open up new technologies that don’t require traditional power sources.

It also lowers the bar for what life needs to sustain itself, particularly on other planets. Our search for extraterrestrial life generally focuses on ingredients that are found across wide portions of the Earth. There’s been some understanding of the extreme environments microbes can live in, such as along hydrothermal vents, but surviving on wafting carbon monoxide certainly expands our notion of what qualifies as ‘habitable.’

Source: Living on thin air—microbe mystery solved, Phys.org