Tagmicrobiology

Gut–brain link could shed light on mental health

Nature reports:

Companies selling ‘probiotic’ foods have long claimed that cultivating the right gut bacteria can benefit mental well-being, but neuroscientists have generally been sceptical. Now there is hard evidence linking conditions such as autism and depression to the gut’s microbial residents, known as the microbiome. And neuroscientists are taking notice — not just of the clinical implications but also of what the link could mean for experimental design. […]

The evidence that probiotics affect human behaviour “is minimal to say the least”, Mazmanian acknowledges. Still, he says, a growing number of researchers are starting to look at some mental illnesses through a microbial lens.

Full Story: Nature: Gut–brain link grabs neuroscientists

Previously:

Networks, Bacteria, and the Illusion of Control

Can Bacteria Make You Smarter?

Humans Are Really Just Biomechanical Suit-Cities For Bacteria

Using Swarm Intelligence to Build Targeted Anti-Cancer Nano-Drugs

Nanoparticles and insect swarms

The results of Geoffrey von Maltzahn et al. in their Nature Materials publication reveal that nanoparticles that communicate with each other can deliver more than 40-fold higher doses of chemotherapeutics (anti-cancer drugs) to tumors than nanoparticles that do not communicate can deliver. These results show the potential for nanoparticle communication to amplify drug delivery over that achievable by nanoparticles that work alone, similar to how insect swarms perform better as a group than the individual insects do on their own.

Scientific American: Learning from Insect Swarms: Smart Cancer Targeting

(via Social Physicist)

Bacteria Loves Caffeine Too

Think you live on caffeine? You’re still no match for a newly described bitty bacteria called Pseudomonas putida CBB5. These little guys can feast on pure caffeine all day—and presumably all night—long. And researchers have now located just how they accomplish this arguably admirable feat.

Celebrated and cursed, caffeine is actually an alluring blend of carbon, hydrogen, nitrogen and oxygen, and the clever bacterium uses specialized enzymes as it “breaks caffeine down into carbon dioxide and ammonia,” Ryan Summers, a doctoral researcher in chemical and biochemical engineering at the University of Iowa, said in a prepared statement.

Scientific American: Newly Discovered Bacteria Lives on Caffeine

Did Scientists Discover Bacteria in Meteorites?

Doesn’t look like it. P.Z. Meyers writes:

Fox News broke the story, which ought to make one immediately suspicious — it’s not an organization noted for scientific acumen. But even worse, the paper claiming the discovery of bacteria fossils in carbonaceous chondrites was published in … the Journal of Cosmology. I’ve mentioned Cosmology before — it isn’t a real science journal at all, but is the ginned-up website of a small group of crank academics obsessed with the idea of Hoyle and Wickramasinghe that life originated in outer space and simply rained down on Earth. It doesn’t exist in print, consists entirely of a crude and ugly website that looks like it was sucked through a wormhole from the 1990s, and publishes lots of empty noise with no substantial editorial restraint. For a while, it seemed to be entirely the domain of a crackpot named Rhawn Joseph who called himself the emeritus professor of something mysteriously called the Brain Research Laboratory, based in the general neighborhood of Northern California (seriously, that was the address: “Northern California”), and self-published all of his pseudo-scientific “publications” on this web site. […]

We’ve actually got to look at the claims and not dismiss them because of their location. […]

Reading the text, my impression is one of excessive padding. It’s a dump of miscellaneous facts about carbonaceous chondrites, not well-honed arguments edited to promote concision or cogency. The figures are annoying; when you skim through them, several will jump out at you as very provocative and looking an awful lot like real bacteria, but then without exception they all turn out to be photos of terrestrial organisms thrown in for reference. The extraterrestrial ‘bacteria’ all look like random mineral squiggles and bumps on a field full of random squiggles and bumps, and apparently, the authors thought some particular squiggle looked sort of like some photo of a bug. This isn’t science, it’s pareidolia. They might as well be analyzing Martian satellite photos for pictures that sorta kinda look like artifacts.

Pharyngula: Did scientists discover bacteria in meteorites?

You can find the paper here if you’d like to check it out for yourself.

Previous coverage of astrobiology can be found here.

Arsenic-Based Life Possible, But Not Certain

Mono Lake

Boing Boing’s Maggie Koerth-Baker adds a quick dose of realism and clarity to this morning’s NASA announcement:

Not everybody agrees that this research proves the bacteria are capable of replacing phosphate with arsenic. You can read more about that debate in the really nicely done article at Nature News that I’m quoting above.

Also, even if this is proof that phosphate isn’t necessary for life, we still don’t know whether the bacteria in question actually replace their phosphate in the wild. Right now, this is something humans are convincing it to do in a petri dish. That’s why it’s not entirely fair to say that weird life has been discovered—all this paper does (if it stands up to the coming onslaught of scrutiny) is show that weird life is, in fact, possible.

But that’s still a pretty big deal. However you slice it, this is an extremely interesting little bacterium. It isn’t alien. It still has the same basic DNA structure we all know and love. It just might be able to use different chemicals to build that old, familiar structure. And that’s pretty cool on its own.

Also, Mono Lake sounds pretty cool:

A couple of years ago, scientists found bacteria in California’s Mono Lake that used arsenic compounds, rather than water, as an ingredient of photosynthesis. In fact, there’s been a lot of weird life research centered around Mono Lake. Hot, salty, low in oxygen, and high in lots of other useful chemicals, the Lake has been described as a here-and-now model of the old primordial soup.

Boing Boing: Weird life found on Earth—kind of, maybe

Photo by Chris Streeter

NASA Discovers New Life on Earth: Bacteria with Arsenic-Based DNA

Arsenic

Update: Please see this update on how, although this research is significant, it doesn’t necessarily indicate that there is arsenic-based bacteria in the wild.

Evidence that the toxic element arsenic can replace the essential nutrient phosphorus in biomolecules of a naturally occurring bacterium expands the scope of the search for life beyond Earth, according to Arizona State University scientists who are part of a NASA-funded research team reporting findings in the Dec. 2 online Science Express.

It is well established that all known life requires phosphorus, usually in the form of inorganic phosphate. In recent years, however, astrobiologists, including Arizona State University professors Ariel Anbar and Paul Davies, have stepped up conversations about alternative forms of life. […]

Davies has previously speculated that forms of life different from our own, dubbed “weird life,” might even exist side-by-side with known life on Earth, in a sort of “shadow biosphere.” The particular idea that arsenic, which lies directly below phosphorous on the periodic table, might substitute for phosphorus in life on Earth, was proposed by Wolfe-Simon and developed into a collaboration with Davies and Anbar. Their hypothesis was published in January 2009, in a paper titled “Did nature also choose arsenic?” in the International Journal of Astrobiology.

PhysOrg: Deadly arsenic breathes life into organisms

Bacteria Survives in Space, Without Oxygen, for a Year and a Half

space-bacteria

The bugs were put on the exterior of the space station to see how they would cope in the hostile conditions that exist above the Earth’s atmosphere.

And when scientists inspected the microbes a year and a half later, they found many were still alive.

These survivors are now thriving in a laboratory at the Open University (OU) in Milton Keynes.

The experiment is part of a quest to find microbes that could be useful to future astronauts who venture beyond low-Earth orbit to explore the rest of the Solar System. […]

This type of research also plays into the popular theory that micro-organisms can somehow be transported between the planets in rocks – in meteorites – to seed life where it does not yet exist.

BBC: Beer microbes live 553 days outside ISS

Interestingly, the bacteria selected weren’t known extremophiles, they were selected apparently at random.

Disrupting Bacterial Communications Could Compliment Antibiotics

Quorum sensing diagram

Chatter between bacterial cells may stall healing of skin wounds, and sabotaging that chitchat could offer another way to battle infection, new research suggests.

Making Pseudomonas aeruginosa deaf to the molecular signals that the bacteria use to talk to each other would offer a kind of antibiotic therapy that doesn’t kill bacterial cells but rather strikes at their ability to attack human cells en masse, Jasper Jacobsen of the Statens Serum Institute in Copenhagen said May 24 at a meeting of the American Society for Microbiology.

Science News: Bacterial chitchat proves distracting for wound healing

See also:

Hacking Your Body’s Bacteria for Better Health

Bacteria vs. Humans: Score One for Us

Talking to bacteria

Scientists discover missing link in the emergence of life

inorganic life

Philosophers and scientists have argued about the origins of life from inorganic matter ever since Empedocles (430 B.C.) argued that every thing in the universe is made up of a combination of four eternal ‘elements’ or ‘roots of all’: earth, water, air, and fire, and that all change is explained by the arrangement and rearrangement of these four elements. Now, scientists have discovered that simple peptides can organize into bi-layer membranes. The finding suggests a “missing link” between the pre-biotic Earth’s chemical inventory and the organizational scaffolding essential to life.

Daily Galaxy: Scientists Discover Missing Link Between Organic and Inorganic Life

(Thanks Wade)

Pentagon Looks to Breed Immortal ‘Synthetic Organisms,’ Molecular Kill-Switch Included

darpa organisms

The Pentagon’s mad science arm may have come up with its most radical project yet. Darpa is looking to re-write the laws of evolution to the military’s advantage, creating “synthetic organisms” that can live forever — or can be killed with the flick of a molecular switch.

As part of its budget for the next year, Darpa is investing $6 million into a project called BioDesign, with the goal of eliminating “the randomness of natural evolutionary advancement.” The plan would assemble the latest bio-tech knowledge to come up with living, breathing creatures that are genetically engineered to “produce the intended biological effect.” Darpa wants the organisms to be fortified with molecules that bolster cell resistance to death, so that the lab-monsters can “ultimately be programmed to live indefinitely.”

Of course, Darpa’s got to prevent the super-species from being swayed to do enemy work — so they’ll encode loyalty right into DNA, by developing genetically programmed locks to create “tamper proof” cells. Plus, the synthetic organism will be traceable, using some kind of DNA manipulation, “similar to a serial number on a handgun.” And if that doesn’t work, don’t worry. In case Darpa’s plan somehow goes horribly awry, they’re also tossing in a last-resort, genetically-coded kill switch.

Danger Room: Pentagon Looks to Breed Immortal ‘Synthetic Organisms,’ Molecular Kill-Switch Included

(via Edge of Tomorrow)

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