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Bacteria: Marvelous Microbes; Prodigious Prokaryotes

rynner2

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...their lives seemed, well, boring. The "sole ambition" of a bacterium, wrote geneticist François Jacob in 1973, is "to produce two bacteria."

New research suggests, however, that microbial life is much richer: highly social, intricately networked, and teeming with interactions. Bassler and other researchers have determined that bacteria communicate using molecules comparable to pheromones. By tapping into this cell-to-cell network, microbes are able to collectively track changes in their environment, conspire with their own species, build mutually beneficial alliances with other types of bacteria, gain advantages over competitors, and communicate with their hosts - the sort of collective strategizing typically ascribed to bees, ants, and people, not to bacteria.
....
[These] discoveries suggest that the ability to create intricate social networks for mutual benefit was not one of the crowning flourishes in the invention of life. It was the first.
A very interesting article, in full here.
 
Communicating bacteria...
this possibility was used by Greg Bear in /slant
(that's the name of the novel BTW)
one of the intelligent computers is made from bacterial cultures (*the other one is a dna vat brain - basic stuff)

Er - wild assed speculation...
The extremophile bacteria living deep in the Earth's crust apparently make up the majority of the biomass by weight on our planet-(if you were dedicated enough to dig them up and weigh them) and they must have a fair bit of Boron knocking about down there.
If the crustal bacteria can communicate, it is just a million steps from them being intelligent- you could have a huge living brain down there.
And if not on Earth, perhaps on some other planet.
 
Eburacum45 said:
- you could have a huge living brain down there.
Perhaps it is called Gaia.... :eek!!!!:
 
From the front page:

January 12, 2004


Talking Bacteria


Microbes seem to talk, listen and collaborate with one another--fodder for the truly paranoid. Bonnie L. Bassler has been eavesdropping and translating


By Marguerite Holloway


It is far too early in the morning, and Bonnie L. Bassler is charging across the Princeton University campus, incandescent purple coat flying, brown curls bouncing, big laugh booming. She has come directly from the aerobics class she teaches every morning at 6:15--"I get up at exactly 5:42, not a minute earlier, not a minute later," she says emphatically. She says most things with similar energy, and when the conversation turns to her work, she becomes, impossibly, even more dynamic. "I am not meant to be stopped in time," she laughs. "I am supposed to be a blur."

The 41-year-old Bassler--a professor of molecular biology, winner of a 2002 MacArthur Foundation genius award, and occasional actress, dancer and singer--studies bacteria and how they communicate among their own kind and with other species. Quorum sensing, as this phenomenon is called, is a young science. Until recently, no one thought bacteria talked to one another, let alone in ways that changed their behavior, and Bassler has been instrumental in the field's rapid ascension. She has figured out some of the dialects--the genetic and molecular mechanisms different species use--but is best known for identifying what might be a universal language all species share, something she has jokingly referred to as "bacterial Esperanto."


As its moniker suggests, quorum sensing describes the ways in which bacteria determine how many of them there are in the vicinity. If enough are present (a quorum), they can get down to business or up to mischief. For instance, millions of bioluminescent bacteria might decide to emit light simultaneously so that their host, a squid, can glow--perhaps to distract predators and escape. Or salmonella bacteria might wait until their hordes have amassed before releasing a toxin to sicken their host; if the bacteria had acted as independent assassins rather than as an army, the immune system most likely would have wiped them out. Researchers have shown that bacteria also use quorum sensing to form the slimy biofilms that cover your teeth and eat through ship hulls and to regulate reproduction and the formation of spores.

If it all holds up, the implications are enormous. Quorum sensing offers a way to think about evolution. Perhaps early bacteria communicated, then organized themselves according to different functions and, ultimately, into complex organisms. More practically, quorum sensing provides a strategy for medicine: muck up the communication system of dangerous bacteria, such as antibiotic-resistant enterococcus, and perhaps the bugs can't so effectively orchestrate their assault. As Bassler puts it, "You can either make them deaf or you can make them mute."

The study of quorum sensing has its roots in the late 1960s. Two scientists--J. Woodland Hastings and Kenneth H. Nealson--discovered that a marine bacterium, Vibrio fischeri, produced light when its population reached a critical size. When fewer were present, the bacteria didn't bioluminesce. The two researchers speculated that the bacteria released a signal--something they called an autoinducer--that cried out, like Horton the elephant's dust speck in the Dr. Seuss book, "We are here! We are here! We are here! We are here!" When the cacophony became loud enough, the assemblage glowed. In 1983 Michael R. Silverman, then at the Agouron Institute in La Jolla, Calif., and a colleague identified the genes for V. fischeri's autoinducer and its receptor.

Bassler came to work with Silverman in 1990, after finishing her doctorate at Johns Hopkins University. She decided to focus on another glowing marine bacterium, V. harveyi, to determine whether its signaling system was similar. She got to work making mutant bacteria--disabling a gene here, a gene there, to see if she could impair the one that triggered the bug to bioluminesce when it was in like company. "You turn off the lights in the room and just look for the ones that are dark when they should be bright or bright when they should be dark. It is genetics for morons," she quips. Bassler found the genes for V. harveyi's autoinducer and its receptor.

She also discovered something surprising. If she knocked out those two genes and put the altered V. harveyi in mixed company--that is, around masses of different species of bacteria--it glowed. "So I knew there was a second system," Bassler remarks. Bacteria "don't have enough room in their genome to be stupid, so there had to be a separate purpose for this system." The foreign bacteria were emitting something that V. harveyi responded to. Bassler called that something autoinducer two (AI-2). In 1994, as the field of quorum sensing was coming alive, Bassler moved to Princeton. Over time, she and others showed that quorum sensing initiates the release of toxins by bacteria such as V. cholerae. And they found that every bacterium they tested has its own personal autoinducer, the one it uses to communicate with its own kind. Gram-negative bacteria such as Pseudomonas aeruginosa use different versions of AHL molecules (acylated homoserine lactones); gram-positive bacteria such as Staphylococcus aureus use peptides.

But most bacteria Bassler looked at also used AI-2. By 1997 "we could see that all these bacteria made this molecule and that it was not just weird, crazy bacteria from the ocean," Bassler recalls. "So we got the idea that the bacteria must have a way of knowing self from other." For Bassler, the idea that different bacteria chat makes perfect sense. "There are 600 species of bacteria on your teeth every morning, and they are in exactly the same structure every single time: this guy is next to that one, is next to that one," she says. "It just seemed to us that you can't do that if the only thing you can detect is yourself. You have to know ‘other.'"

Bassler and her students set out to purify and characterize AI-2. Finally, through the efforts of postdoctoral student Stephan Schauder and the crystallography of Frederick M. Hughson and Xin Chen, they got it. AI-2 is an unusual package--a sugar with a boron sitting in the middle of it. "What is amazing about that molecule is that it is the first ever to have a biological function for boron. Ever!" Bassler exclaims.

Now Bassler and her colleagues are trying to determine whether AI-2 is, indeed, one molecule that works alone as a signal and does not combine with other molecules to give rise to slightly different "languages." If it is the latter, no more Esperanto. "Her work has been truly superb," comments microbiologist Richard P. Novick of New York University. "But there is argument about where [AI-2] comes from and why. And what role it plays in different systems is unclear."

Some scientists are also concerned that aspects of quorum sensing--but not Bassler's findings--have been slightly overinterpreted. "Do bacteria want to communicate with each other, or is it just by accident?" asks Stephen C. Winans, a microbiologist at Cornell University. "This idea has taken hold that these bacteria want to communicate with each other. It may be just too good to be true."

Bassler's drive--her friend and former mentor Silverman describes her as "intensely motivated," "on a quest" and "just fierce"--suggests that she will hear bacteria's every last word. For the time being, she remains focused on understanding AI-2. "I want it all to be one thing, so I am sure that is wrong," she says. "I want it to be one thing because that is better if you want to make a drug, right?" Bassler is one of several quorum-sensing researchers working with companies to develop drugs. In 1999 she formed a company called Quorex with a former colleague from Agouron. Although her involvement is limited at the moment, she is hopeful that the start-up will find new antibacterials. "This was really considered fringe science," Bassler says. "Now it is this amazing field that didn't even exist 10 years ago."

http://www.scientificamerican.com/a...articleID=0001F2DF-27D8-1FFB-A7D883414B7F0000
 
I remember seeing in a Danish program someone had come up with something which could disturb the way bacteria talked together. It meant that they were unable to form biofilm on ship hulls and such.
 
Does this mean that bacteria have memories and are capable of decision making?
 
I'm too paranoid not to be worried about bacteria plotting and scheming. They've already bred that Super-Bacteria that can't be killed.
 
Super Bacteria? You don't just mean the ones that are immune to penicillin do you?
 
Probably. But since when did cold hard facts stop a good mass panic?
 
Ahhhh, on more step towards Stanislaw Lem's science of Eruntics!

Now if I could just teach those bacteria to tell me the winning lottery numbers!! :madeyes:
 
Clearly rocket science is a lot easier than we first thought

Bacteria help make missile fuel

By Arran Frood

Scientists have recruited an unusual ally in their quest to produce safer, cheaper rocket fuel: bacteria.

The microbes help make a key ingredient of a fuel mix used in missiles but could also reduce the cost of drugs used to lower cholesterol levels.

The US military commissioned the work after discovering navy chemists were using the cheaper, but more dangerous, chemical nitroglycerine in its place.

Details are published in the Journal of the American Chemical Society.

The conventional manufacture of the propellant butanetriol costs (£16) to (£22) per pound. Together, the Navy and Army purchase about 15,000 pounds (6,803 kg) per year.

Butanetriol is used to make another chemical called butanetriol trinitrate (BTTN) which is employed in the fuel mix of missiles such as the Hellfire, an air-to-ground attack missile fired from military helicopters such as the Apache and unmanned Predator drones.

Reducing costs

If the costs of producing butanetriol could be reduced to (£5) or (£8) per pound, demand from the two armed forces could rise to 180,000 pounds (82,000 kg) per year, replacing nitroglycerine in many military and civilian applications.

Scientists are always on the look out for safer alternatives to nitroglycerine as it is notoriously volatile.

The brother of Swedish chemist Alfred Nobel died in an accident during an attempt to manufacture the chemical - a process that later made Alfred rich.

He used the proceeds to launch the coveted Nobel prizes for science, peace, economics and literature that are still awarded today.

There are safer alternatives to nitroglycerine, but the chemical is effective and cheap to produce.

As a result, some two million pounds (907,000 kg) of it are made each year, carrying the same hazards during manufacture that confronted Nobel in the 1860s.

Even burn

By modifying key genes in the bacteria E. coli and Pseudomonas fragi , researchers led by Dr John Frost of Michigan State University, US, have teased the microbes into making butanetriol from simple carbohydrates obtained from corn and sugar beet.

The key aspect is simplicity, we are teaching the microbes to be chemical catalysts
Dr John Frost, Michigan State University

The butanetriol is then nitrated to produce BTTN, which allows the missile rocket's propellant mix to burn more evenly, similar to the way that some cigarette paper is treated.

"The key aspect is simplicity, we are teaching the microbes to be chemical catalysts," said Dr Frost. "At the moment we are using two bacteria, but the goal is to refine the process to just one step. Microbes allow you to deal in large volumes, which make the process commercially viable.

"Compared with nitroglycerine, which is pretty unforgiving stuff, the BTTN is safer in all aspects of manufacture and use."

Biological factories

He adds that the bio-production of butanetriol is easier and less polluting than its conventional synthesis because it takes place between room and body temperature and at normal atmospheric pressure.

Naturally occurring bacteria have been used to make bread, cheese, beer and wine.

More recently, bacteria have been turned into tiny biological factories by genetic modification to produce a variety of chemicals: antibiotics, nylon derivatives and human insulin for diabetes sufferers.

The production of butanetriol using bacteria is an unusual combination of technologies with green credentials, though the ultimate product is controversial.

But there are wider benefits for human health: butanetriol is also a chemical precursor to two cholesterol-lowering drugs prescribed to those at risk of a heart attack.

Story from BBC NEWS: http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/3450853.stm
Published: 2004/02/02 11:52:10 GMT
© BBC MMIV
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/3450853.stm
 
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UCLA biochemists reveal the first structural details of a family of mysterious objects called microcompartments that seem to be present in a variety of bacteria. The discovery was published Aug. 5 in the journal Science.


The first three-dimensional structure of the protein building blocks that make up the shell of bacterial microcompartments ... determined by Todd Yeates, Cheryl Kerfeld and their UCLA biochemistry colleagues. (Credit: T. Yeates, C. Kerfeld/ UCLA Chemistry and Biochemistry)



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"This is the first look at how microcompartments are built, and what the pieces look like," said Todd O. Yeates, UCLA professor of chemistry and biochemistry, and a member of the UCLA-DOE Institute of Genomics and Proteomics. "These microcompartments appear to be highly evolved machines, and we are just now learning how they are put together and how they might work. We can see the particular amino acids and atoms."

A key distinction separating the cells of primitive organisms like bacteria, known as prokaryotes, from the cells of complex organisms like humans is that complex cells -- eukaryotic cells -- have a much higher level of subcellular organization; eukaryotic cells contain membrane-bound organelles, such as mitochondria, the tiny power generators in cells. Cells of prokaryotes have been viewed as very primitive, although some contain unusual enclosures known as microcompartments, which appear to serve as primitive organelles inside bacterial cells, carrying out special reactions in their interior.

"Students who take a biology class learn in the first three days that cells of prokaryotes are uniform and without organization, while cells of eukaryotes have a complex organization," Yeates said. "That contrast is becoming less stark; we are learning there is more of a continuum than a sharp divide. These microcompartments, which resemble viruses because they are built from thousands of protein subunits assembled into a shell-like architecture, are an important component of bacteria. I expect there will be a much greater focus on them now."

Yeates' Science paper reveals the first structures of the proteins that make up these shells, and the first high-resolution insights into how they function.

"Those microcompartments have remained shrouded in mystery, largely because of an absence of a detailed understanding of their architecture, of what the structures look like," said Yeates, who also is a member of the California NanoSystems Institute and UCLA's Molecular Biology Institute. "The complete three-dimensional structure is still unknown, but in this paper we have provided the first three-dimensional structure of the building blocks of the carboxysome, a protein shell which is the best-studied microcompartment."

The UCLA biochemists also report 199 related proteins that presumably do similar things in 50 other bacteria, Yeates said.

"Our findings blur the distinction between eukaryotic cells and those of prokaryotes by arguing that bacterial cells are more complex than one would imagine, and that many of them have evolved sophisticated mechanisms," Yeates said.

While microcompartments have been directly observed in only a few organisms, "surely there will be many more," Yeates said. "The capacity to create subcellular compartments is very widespread across diverse microbes. We believe that many prokaryotes have the capacity to create subcellular compartments to organize their metabolic activities."

Yeates' research team includes research scientist and lead author Cheryl Kerfeld; Michael Sawaya, a research scientist with UCLA and the Howard Hughes Medical Institute; Shiho Tanaka, a former UCLA undergraduate who is starting graduate work at UCLA this fall in biochemistry; and UCLA chemistry and biochemistry graduate student Morgan Beeby.

The structure of the carboxysome shows a repeating pattern of six protein molecules packed closely together.

"We didn't know six would be the magic number," Yeates said. "What surprises me is how nearly these six protein molecules fill the space between them. If you take six pennies and place them in the shape of a ring, that leaves a large space in the middle. Yet the shape of this protein molecule is such that when six proteins come together, they nearly fill the space; what struck me is how tightly packed they are. That tells us the shell plays an important role in controlling what comes in and goes out. When we saw how the many hexagons come together, we saw that they filled the space tightly as well."

The UCLA biochemists determined the structures from their analysis of small crystals, using X-ray crystallography. How microcompartments fold into their functional shapes remains a mystery.

Yeates' laboratory will continue to study the structures of microcompartments from other organisms.

If microcompartments can be engineered, biotechnology applications potentially could arise from this research, Yeates said.


The research was federally funded by the U.S. Department of Agriculture, the National Institutes of Health and the U.S. Department of Energy.

http://www.sciencedaily.com/releases/20 ... 104729.htm
 
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Cow Power: Battery Runs on Bovine Stomach Bacteria
James Owen
for National Geographic News

September 9, 2005
Scientists say they have produced clean, renewable energy from the contents of a cow's stomach.

Researchers found they could generate electricity using the bacteria that occur naturally inside a cow's rumen—the first of four stomachs that breaks down grass and other fodder into a digestible mush.

The bovine stomach bacteria add to a growing list of cheap, plentiful, and non-polluting substances that run devices known as microbial fuel cells (MFCs).

MFCs are powered by electrons (the source of electricity) released by bacteria feeding on organic material. The microbes aren't fussy eaters, either. In tests, the bacteria have also fed on dead flies, fruit, even domestic wastewater and produced electricity.

Researchers at Ohio State University found that a pint (half a litre) of a cow's bacteria-infested rumen juice produced about 600 millivolts of electricity. The output is about half the voltage of a rechargeable AA-size battery.

Ann D. Christy, professor of food, agricultural, and biological engineering, said the team tapped into the electron transport system of rumen bacteria.

"The normal metabolism of electro-chemically active micro-organisms allows them to generate a small electrical current when placed in contact with the anode [negative electrode] of the microbial fuel cell," she said.

The cathode, the positive electrode of the experimental battery, was filled with a chemical oxidizing (electron-removing) agent to round out the electrical circuit.

Cow Dung

Undergraduate students working in Christy's lab also managed to generate a similar voltage from microbial fuel cells using cow dung.

"The students put a few of these cells together and were able to fuel their rechargeable batteries over and over again," Christy added.

Farmers in California have already cottoned on to the energy potential of cow dung. Dairy operations are installing so-called methane digester systems, which harness methane, a greenhouse gas released in cattle waste, to generate electricity.

But Christy maintains that her team's cow-powered batteries are a greener, more efficient alternative.

"No methane is involved," she said. "It is a direct conversion into electricity. Therefore no greenhouse gases are released, no combustion inefficiencies are encountered, and capital costs are reduced."


While Christy says her team's microbial fuel cells are the first to use the body fluids of animals, other researchers have developed MFCs that run on human sewage.

At Pennsylvania State University, scientists are working to develop this technology to enable sewage treatment plants to power themselves.

And last month, National Geographic News reported the development of a tiny battery which runs on human urine. The biodegradable batteries are designed as a disposable power source for medical test kits.

Biological Battery

Meanwhile scientists are looking to microbial fuel cells as an energy supply for autonomous robots. These robots could be programmed to find the raw fuel for these cells on their own, becoming completely self-sufficient.

The British-based EcoBot Project has created a robot that runs on flies, which are fed to microbes taken from sewage sludge.

Chris Melhuish, director of the Intelligent Autonomous Systems Laboratory at the University of the West of England in Bristol, leads the project.

"We've shown that just from using the energy from dead flies, EcoBot has created enough power to be able to sense its environment using a temperature probe," he said. The robot can then "process this information, actuate wheels to move slowly towards light, and transmit the information back to a base station over a radio link—all powered by eight dead flies."

"We can also use things like shellfish, such as the carapace [shell] of a prawn or plant material," Melhuish added.

The scientists says there are many possible applications for a robot that can generate energy from its surrounding environment—from monitoring crops on a large farm to gathering data on the ocean floor.

"There are lots of variations on these themes. But whatever it's doing, it's doing it without external power," he added.

Experts say the big question is whether microbial fuel cell power as a form of clean, renewable energy can be scaled up to a degree that would reduce our reliance on fossil fuels.

"I think the prospects are very promising," said Christy of Ohio State University. "But the amounts of electricity from our laboratory-based systems are still small. More research on scale-up is definitely needed."

Melhuish agrees. "I'm not going to put my hand on my heart and say this is definitely going to be the technology for the future," he said. "It might be. But unless we experiment and invest money in finding out how good or bad this thing is, we'll never know. It's got to be worth a [try]."

http://news.nationalgeographic.com/news ... ttery.html
http://news.nationalgeographic.com/news ... ttery.html
 
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Bacteria Can Take Pictures of Themselves
By PAUL ELIAS, AP Biotechnology Writer Wed Nov 23, 3:40 PM ET

SAN FRANCISCO - The notorious E. coli bug made its film debut Wednesday. That's when researchers at the University of California, San Francisco and the University of Texas announced in the journal Nature that they had created photographs of themselves by programming the bacteria — best known for outbreaks of food poisoning — to make pictures in much the same way Kodak film produces images.

It's the latest advance in "synthetic biology," a disputed research movement launched largely by engineers and chemists bent on genetically manipulating microscopic bugs into acting like tiny machines, creating new, powerful and inexpensive ways to make drugs, plastics and even alternatives to fossil fuel.

The field seeks to go beyond traditional genetic engineering feats where a single gene is spliced into bacteria and other cells to manufacture drugs. Synthetic biologists are trying to create complex systems that function as logically and reliably as computers.

Mainstream biologists, however, scoff that biology — life itself — is too unpredictable and prone to genetic mutation to understand, let alone tame and turn into miniature factories.

Bioethicists, meanwhile, fret that synthetic biologists are attempting to create new living creatures and are inventing technology that can readily be used by terrorists.

Still, a growing number of engineers are jumping into the nascent field, whose chief goals include breaking down microbes and other living things into smaller components and reassembling those parts into useful machines.

"There is kind of a hacker culture behind all of this," said Chris Voigt, a University of California, San Francisco researcher who, at 29, was the senior author on the bacteria-as-film paper in Nature.

Voigt and colleagues took from algae light-sensitive genes that emit black compounds and spliced them into a batch of E. coli bacteria. The organisms were then spread on a petri dish that resembles a cookie sheet and placed in an incubator. A high-powered projector cast photographic images of the researchers through a hole on top of the incubator, exposing some of the bacteria to light.

The result: Ghostly images like traditional black-and-white photographs of the researchers responsible for the invention, at a resolution Voigt said was about 100 megapixels, or 10 times sharper than high-end printers.

The work, though, isn't intended for commercial markets.

"They aren't going to put Kodak out of business any time soon," said Massachusetts Institute of Technology researcher Drew Endy, a leading synthetic biologist.

Instead, the creation will be used as a sensor to start and stop more complex genetic engineering experiments. The idea is to create a genetically engineered cell that lays dormant until a laser is shined on it, prompting it into action.

Such an accomplishment would add to the growing success of a field that is making strides around the world, in such projects as:

Scientists in Israel made the world's smallest computer by engineering DNA to carry out mathematical functions.

J. Craig Venter, the entrepreneurial scientist who mapped the human genome and launched the Rockville, Md.-based research institute named after himself, is attempting to create novel organisms that can produce alternative fuels.

With a $42.6 million grant that originated at the Bill and Melinda Gates Foundation, Berkeley researchers are engineering the E. coli bug with genes from the wormwood plant and yeast to create a new malaria drug.

Even as they wrestle with scientific hurdles like controlling genetic mutations, thorny ethical issues are cropping up.

It's cheap and easy to buy individual genes online. They cost about $1 each, down from the $18 apiece charged just a few years ago. Researchers last year created a synthetic polio virus by simply stitching together these mail-order genes.

National security experts and even synthetic biologists themselves are concerned that rogue scientists could create new biological weapons — like deadly viruses that lack natural foes. They also worry about innocent mistakes: organisms that could potentially create havoc if allowed to reproduce outside the lab.

Researchers are casting about for ways to self-police the field before it really takes off. Leaders in the field have organized a second national conference to grapple with these issues this coming May and the Arthur P. Sloan Foundation in June handed out a $570,000 grant to study the social implications of the new field.

"This is powerful work and we live in an age that many tools and technologies can be turned into weaponry," said Laurie Zoloth, a bioethicist at Northwestern University. "You always have the problem of dual-use in every new technology. Steel can be used to make sewing needles or spears."
http://news.yahoo.com/s/ap/20051123/ap_on_sc/bacterial_film
 
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Bacteria alive (more or less) in 86-million-year-old seabed clay
http://phys.org/news/2012-05-bacteria-a ... -clay.html
May 18th, 2012 in Biology / Cell & Microbiology

(Phys.org) -- A new study by scientists from Denmark and Germany has found live bacteria trapped in red clay deposited on the ocean floor some 86 million years ago. The bacteria use miniscule amounts of oxygen and move only extremely slowly.

Researchers led by Hans Røy from the Center for Geomicrobiology at Aarhus University in Denmark, extracted samples from columns of sediment up to around 30 meters beneath the sea floor in the region of rotating currents north of Hawaii known as the North Pacific Gyre. The sediment columns, built up by deposition of clay, dead algae and crustaceans, and dust, can be as much as several kilometres thick, with the most ancient sediment at the bottom of the columns.

The team used sensitive oxygen sensors to measure the oxygen concentration in the sediment cores. Knowing how much oxygen should have been present at each level allowed them to determine if oxygen was “missing,” which meant it had been consumed by microbes. In most regions of seabed examined previously, all the oxygen is consumed within the first 10 cm of sediment.

They discovered that bacteria within the clay were slowly using the oxygen, and remained alive even at a depth of around 30 meters, even though they have not had access to fresh organic matter for millions of years.

Oxygen respiration rates at the sediment-water interface were 10 ?M per liter of sediment per year, and dropped to 0.001 ?M at 30 meters, where the sediments were estimated to be 86 million years old. Cellular respiration rates also decreased with depth but stabilized at 0.001 femtomoles of oxygen per cell per day at 1.10 meters beneath the sea floor. (A femtomole is a billionth of a millionth of a mole.) Røy said the team had “no clue” how the microbes were able to subsist on so little oxygen.

Dr. Røy’s team estimated the turnover of the bacterial biomass would take from a few hundred to a few thousand years, but the turnover could represent cell repair rather than cell division. The bacteria may be operating on the absolute minimum energy requirement, which is just sufficient to keep their DNA and enzymes working, and to maintain an electric potential across their cell membranes.

The activity of the bacteria is so slow that Røy likened it to staring at a tree to watch it grow taller, and said the team did not know if the bacteria were reproducing, or if they were the same bacteria that had been deposited in the sediment and were “just not dying.” He estimated they must be at least 1000 years old, but could be much older. They have no contact with sunlight or the surface.

Røy said that an estimated 90 percent of the Earth’s microbial life may exist under the sea floor, but studying them was difficult because the methods have been developed in studying bacteria with rapid life-cycles.

Dr Røy said similar life forms could exist on other planets; if microbial life had ever existed, they could remain alive even if cut off from the surface for millions of years. He also said it gave him a greater appreciation of life on Earth, that you can store clay on the bottom of the sea for 86 million years and find that “somebody’s still living in it.”

More information: Aerobic Microbial Respiration in 86-Million-Year-Old Deep-Sea Red Clay, Science 18 May 2012: Vol. 336 no. 6083 pp. 922-925. DOI: 10.1126/science.1219424

ABSTRACT

Microbial communities can subsist at depth in marine sediments without fresh supply of organic matter for millions of years. At threshold sedimentation rates of 1 millimeter per 1000 years, the low rates of microbial community metabolism in the North Pacific Gyre allow sediments to remain oxygenated tens of meters below the sea floor. We found that the oxygen respiration rates dropped from 10 micromoles of O2 liter?1 year?1 near the sediment-water interface to 0.001 micromoles of O2 liter?1 year?1 at 30-meter depth within 86 million-year-old sediment. The cell-specific respiration rate decreased with depth but stabilized at around 10?3 femtomoles of O2 cell?1 day?1 10 meters below the seafloor. This result indicated that the community size is controlled by the rate of carbon oxidation and thereby by the low available energy flux.
http://phys.org/news/2012-05-bacteria-a ... -clay.html
 
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The notion of bacteria that might feed on manganese took more than a century to confirm as reality.
Microbiologists Discover Bacteria That Feed on Metal, Ending a Century-Long Search

Finding ends a century-long search for microbes that live on manganese.

Caltech microbiologists have discovered bacteria that feed on manganese and use the metal as their source of calories. Such microbes were predicted to exist over a century ago, but none had been found or described until now.

“These are the first bacteria found to use manganese as their source of fuel,” says Jared Leadbetter, professor of environmental microbiology at Caltech who, in collaboration with postdoctoral scholar Hang Yu, describes the findings in the July 16 issue of the journal Nature. “A wonderful aspect of microbes in nature is that they can metabolize seemingly unlikely materials, like metals, yielding energy useful to the cell.”

The study also reveals that the bacteria can use manganese to convert carbon dioxide into biomass, a process called chemosynthesis. Previously, researchers knew of bacteria and fungi that could oxidize manganese, or strip it of electrons, but they had only speculated that yet-to-be-identified microbes might be able to harness the process to drive growth. ...

FULL STORY: https://scitechdaily.com/microbiolo...t-feed-on-metal-ending-a-century-long-search/
 
In First-of-Its-Kind Discovery, Scientists Confirm Bacteria Have a 24-Hour Body Clock

In a first-of-its-kind discovery, scientists have found that a species of non-photosynthetic bacteria are regulated by the same circadian rhythms that hold sway over so many other life-forms.

In humans, our circadian rhythms act as a kind of biological clock in our cells, controlling virtually all the processes in our bodies, influencing when we sleep and rise, plus the functioning of our metabolism, and cognitive processes.

This internal time-keeping, which revolves around a 24-hour cycle, is driven by our circadian clock, and the same core phenomenon has been observed in many other kinds of organisms as well, including animals, plants, and fungi.

For a long time, however, it's been unclear whether bacteria at large are also subject to the dictates of circadian rhythms.

The phenomenon has been demonstrated in photosynthetic bacteria, which use light to make chemical energy, but as for whether other kinds of bacteria also possess circadian clocks has long remained a mystery – until now.

"We've found for the first time that non-photosynthetic bacteria can tell the time," explains chronobiologist Martha Merrow from the Ludwig Maximilian University of Munich.

"They adapt their molecular workings to the time of day by reading the cycles in the light or in the temperature environment." ...

FULL STORY: https://www.sciencealert.com/scient...our-body-clock-in-first-of-its-kind-discovery
 
"We've found for the first time that non-photosynthetic bacteria can tell the time," explains chronobiologist Martha Merrow from the Ludwig Maximilian University of Munich".
How do they know when the clocks go back or forward... :actw:
 
Has anyone proposed why an organism with a life cycle measurable in hours would evolve with a circadian rhythm ?
 
Has anyone proposed why an organism with a life cycle measurable in hours would evolve with a circadian rhythm ?

The average lifespan of an individual bacterium is measured in minutes or hours, but there are bacteria which can survive for days, weeks, and even years.
 
It was precisely in a Microbiology class in 1985 when the question of a circadian rhythm in prokaryotes came up. I was told that (a) the zeitgeber mechanism was in the cell nucleus (which bacteria don't have) and (b) there was no point in having an endogenous rhythm that's longer than your lifespan. Little did I know that approx 24 hours later this would all apparently become obsolete. I sort of understand the need for cycles in photosynthetic bacteria (cyanobacter is the old 'blue/green algae") that require light, but not in non photosynthetic micro-organisms.
Still, live and learn.
 
Dormant = "dead"? Not so much ... Newly published research indicates dormant bacteria (e.g., spores) are capable of detecting and responding to environmental conditions using their stored energy reserve.
Unexpected Activity in 'Dead' Bacteria Detected by Scientists

Scientists have detected unexpected activity in dormant bacteria spores, showing for the first time that even when they're physiologically 'dead', the organisms are still aware of their surroundings.

Using a stored supply of charged particles for energy, rather than their usual fuel, the bacteria could actively respond to tiny changes in nutrient levels to determine a prime time to wake.

The discovery challenges our understanding of not just how disease spreads, but also how life could survive in extreme states here on Earth and beyond.

"This work changes the way we think about spores, which were considered to be inert objects," says molecular biologist and lead researcher Gürol Süel from the University of California San Diego.

"We show that cells in a deeply dormant state have the ability to process information. We discovered that spores can release their stored electrochemical potential energy to perform a computation about their environment without the need for metabolic activity." ...

The implications also spread beyond disease management here on Earth – it's often thought that one way we may encounter extraterrestrial life is in similar dormant states.

"If scientists find life on Mars or Venus, it is likely to be in a dormant state and we now know that a life form that appears to be completely inert may still be capable of thinking about its next steps," says Süel. ...
FULL STORY: https://www.sciencealert.com/unexpected-activity-in-dead-bacteria-detected-by-scientists
 
Here are the bibliographic details and abstract from the published research report.


Electrochemical potential enables dormant spores to integrate environmental signals
KAITO KIKUCHI, LETICIA GALERA-LAPORTA, COLLEEN WEATHERWAX, et al.
SCIENCE. 6 Oct 2022. Vol 378, Issue 6615, pp. 43-49
DOI: 10.1126/science.abl7484

Abstract
The dormant state of bacterial spores is generally thought to be devoid of biological activity. We show that despite continued dormancy, spores can integrate environmental signals over time through a preexisting electrochemical potential. Specifically, we studied thousands of individual Bacillus subtilis spores that remain dormant when exposed to transient nutrient pulses. Guided by a mathematical model of bacterial electrophysiology, we modulated the decision to exit dormancy by genetically and chemically targeting potassium ion flux. We confirmed that short nutrient pulses result in step-like changes in the electrochemical potential of persistent spores. During dormancy, spores thus gradually release their stored electrochemical potential to integrate extracellular information over time. These findings reveal a decision-making mechanism that operates in physiologically inactive cells.

SOURCE: https://www.science.org/doi/10.1126/science.abl7484
 
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