Cell biology

Organisms found that hover indefinitely between life and death

Spread the love

Researchers have found some of the oldest and slowest life forms on Earth:

In a bid to hone in on the lower energy limits for life, Hans Røy at Aarhus University in Denmark probed the clays below the North Pacific gyre. Under the microscope, he found a community made up of bacteria and single-celled organisms called archaea in vanishingly small numbers.

“There are only 1000 tiny cells in 1 cubic centimetre of sediment, so finding just one is literally like hunting for a needle in a haystack.”

The microbes rely on oxygen, carbon and other nutrients in their deep environment to live, but Røy’s team found that carbon is so limited that the cells respire oxygen 10,000 times slower than bacteria in lab-grown cultures.

Røy thinks the microbial community is so sparse, and the metabolic rates so low, that the nutrient levels probably represent the bare minimum required to keep cellular enzymes and DNA working. “It looks like we have reached the absolute lower limit for the metabolism of cells,” he says.Colin Barras, “Buried microbes exist at limit between life and death” at New Scientist

Some of the cells may be thousands of years old, he thinks, which is practically living forever in cell terms.

Study of such extreme cells might shed light on the constraints and tradeoffs of life, now and in the past, and possibly elsewhere in the universe.

See also: Light-loving cyanobacteria found, improbably, nearly 2,000 feet underground


Life form found at abyssal depths

Follow UD News at Twitter!

4 Replies to “Organisms found that hover indefinitely between life and death

  1. 1
    polistra says:

    Probably not wise to say “It looks like we’ve found the lower limit” of any variable. Considering the cascade of earlier-than-thought and sparser-than-thought and simpler-than-thought and hotter-than-thought, there’s no reason to assume ANY limits for bacteria. Just take off the theory goggles and keep looking.

  2. 2
    bornagain77 says:

    Of related interest:

    Electrical Communication in Bacteria – August 2010
    Excerpt: These responses occurred too quickly for any sort of chemical exchange or molecular process such as osmosis, says Nielsen. The most plausible option, his team reports in the 25 February issue of Nature, is that the bacteria are somehow communicating electrically by transmitting electrons back and forth. How exactly they do this is unclear,

    Electric Bugs: New Microbe Forms Living, Deep-Sea Power Cables – Oct. 24, 2012
    Excerpt: The world’s deep seafloors are dark and airless places, but vast swaths may pulse gently with energy conducted through a type of newly discovered bacteria that forms living electrical cables.
    The bacteria were first detected in 2010 by researchers perplexed at chemical fluctuations in sediments from the bottom of Aarhus Bay in Denmark. Almost instantaneously linking changing oxygen levels in water with reactions in mud nearly an inch below, the fluctuations occurred too fast to be explained by chemistry.
    Only an electrical signal made sense — but no known bacteria could transmit electricity across such comparatively vast distances. Were bacteria the size of humans, the signals would be making a journey 12 miles long.,,,
    Seen through an electron microscope, the Desulfobulbaceae — the researchers haven’t yet given them a genus or species name — appear in blue. They link end-to-end, forming filaments nearly an inch in length.,,,
    In just one teaspoon of mud, the researchers found a full half-mile of Desulfobulbaceae cable, and it’s not just a Danish phenomenon. Nielsen said other researchers have sent him samples from seafloors around the world, including Tokyo Bay. It’s possible that, at the microbial level, the deep seafloor is humming with current.
    With so much electricity being transferred, are other organisms tapping the lines? Might the Desulfobulbaceae be a power source for entire as-yet-unappreciated deep-sea microbial ecologies, which in turn shape some of the planet’s fundamental biogeochemical processes? That’s “an interesting possibility,” said Nielsen,,
    ,,the Desulfobulbaceae are definitely breaking down iron sulfides and carbonates in deeper sediment, while generating iron oxide and magnesium calcite at the surface, Nielsen said. The latter are important compounds for life in the oceans above, and ultimately on land. If the new Desulfobulbaceae are as widespread and populous as they seem, they could be an important component of life’s deep-time cycles.

    Life forms that live on pure energy? Yes. – July 18, 2014
    Excerpt: The discovery of electric bacteria shows that some very basic forms of life can do away with sugary middlemen and handle the energy in its purest form – electrons, harvested from the surface of minerals. “It is truly foreign, you know,” says Nealson. “In a sense, alien.”Nealson’s team is one of a handful that is now growing these bacteria directly on electrodes, keeping them alive with electricity and nothing else – neither sugars nor any other kind of nutrient. The highly dangerous equivalent in humans, he says, would be for us to power up by shoving our fingers in a DC electrical socket.

    Biological Information, a Mile and a Half Beneath the Ocean Floor – December 16, 2014
    Excerpt: The International Ocean Discovery Program (IODP) sent their drill down to a depth of 2400 meters — a mile and a half. “The tiny, single-celled organisms survive in this harsh environment on a low-calorie diet of hydrocarbon compounds and have a very slow metabolism,” ,,
    Everywhere we look, even in the harshest environments, life seems to find a way to survive.

    Collecting Census Data On Microbial Denizens of Hardened Rocks Dec. 9, 2013
    Excerpt: What they’re finding is that, even miles deep and halfway across the globe, many of these (microbial)communities are somehow quite similar.
    The results,,, suggest that these communities may be connected,,,
    he said. “we’re seeing the same types of organisms everywhere we look.”
    Schrenk leads a team,, studying samples from deep underground in California, Finland and from mine shafts in South Africa. The scientists also collect microbes from the deepest hydrothermal vents in the Caribbean Ocean.
    “It’s easy to understand how birds or fish might be similar oceans apart,” Schrenk said. “But it challenges the imagination to think of nearly identical microbes 16,000 kilometers apart from each other in the cracks of hard rock at extreme depths, pressures and temperatures.”
    “Integrating this region into existing models of global biogeochemistry and gaining better understanding into how deep rock-hosted organisms contribute or mitigate greenhouse gases (and toxic metals) could help us unlock puzzles surrounding modern-day Earth, ancient Earth,,,

    Bacteria Rule the Earth – David F. Coppedge – December 14, 2017
    A single sand grain harbours up to 100,000 microorganisms from thousands of species.” Your visit to the beach will never be the same. The sand you sit on, build sand castles with and bury yourself in is crawling with germs. But not to worry; they’re good germs. They’re doing you and the world a favor by helping keep the ocean clean and keep earth’s nitrogen and carbon cycles going.,,,
    You travel to Antarctica. Now are you germ-free? No;,,, Surprisingly, the same kinds of bacteria live at both poles.,,,

    Do bacteria rule the Earth? Without really trying? – December 22, 2017

  3. 3
    bornagain77 says:

    Ocean’s most abundant organisms have clear daily cycles – July 10, 2014
    Excerpt: Imagine the open ocean as a microbial megacity, teeming with life too small to be seen. In every drop of water, hundreds of types of bacteria can be found. Now scientists have discovered that communities of these ocean microbes have their own daily cycles — not unlike the residents of a bustling city who tend to wake up, commute, work, and eat at the same times.,,,
    “I like to say they are singing in harmony,” said Edward F. DeLong, professor of Oceanography at University of Hawaii,,,
    What scientists saw was intriguing: different species of bacteria expressing different types of genes in different, but consistent, cycles — turning on, for example, the type of restorative genes needed to rebuild their solar-collecting powers at night, then ramping up with different gene activity to build new proteins during the day. “The regularity and timing of individual microbial activities is somewhat like a new shift of hourly workers punching in and out of the clock, day after day,” DeLong said.,,,
    “There are some fundamental laws to be learned about how organisms interact, to make the system work better as a whole and be more efficient,” DeLong said.

    Oceanic microbes behave in a synchrony across ocean basins – March 16, 2015
    Excerpt: Researchers have found that microbial communities in different regions of the Pacific Ocean displayed strikingly similar daily rhythms in their metabolism despite inhabiting extremely different habitats — the nutrient-rich waters off California and the nutrient-poor waters north of Hawai’i. Furthermore, in each location, the dominant photoautotrophs appear to initiate a cascade effect wherein the other major groups of microbes perform their metabolic activities in a coordinated and predictable way.,,,
    The bacterial groups common to both ecosystems displayed the same transcriptional patterns and daily rhythms — as if each group is performing its prescribed role at a precise time each and every day, even though these communities are separated by thousands of miles.
    “Our work suggests that these microbial communities broadly behave in a similar manner across entire ocean basins and that specific biological interactions between these groups are widespread in nature,”,,,
    “Surprisingly, however, our work shows that these extremely different ecosystems exhibit very similar diel cycles, driven largely by sunlight and interspecies microbial interactions,” said Aylward, “This suggests that different microbial communities across the Pacific Ocean, and likely waters across the entire planet, behave in much more orderly ways than has previously been supposed,”

    Bugs in the Atmosphere: Significant Microorganism Populations Found in Middle and Upper Troposphere – Jan. 28, 2013
    Excerpt: In what is believed to be the first study of its kind, researchers used genomic techniques to document the presence of significant numbers of living microorganisms — principally bacteria — in the middle and upper troposphere, that section of the atmosphere approximately four to six miles above Earth’s surface.
    Whether the microorganisms routinely inhabit this portion of the atmosphere — perhaps living on carbon compounds also found there — or whether they were simply lofted there from Earth’s surface isn’t yet known.

    How Microbes Make Earth Habitable – February 10, 2016
    Excerpt: Nitrogen-Fixing Bacterium Does Solo Performance,,,
    Plankton Maintain Carbon Cycle,,,
    Diatoms Promote Diatomic Oxygen,,,

    The Microbial Engines That Drive Earth’s Biogeochemical Cycles – Falkowski 2008
    Excerpt: Microbial life can easily live without us; we, however, cannot survive without the global catalysis and environmental transformations it provides.
    – Paul G. Falkowski – Professor Geological Sciences – Rutgers

    Biologically mediated cycles for hydrogen, carbon, nitrogen, oxygen, sulfur, and iron – image of interdependent ‘biogeochemical’ web

    Of particular note; Darwin himself offered this as a falsification criteria of his theory:

    Natural selection cannot possibly produce any modification in any one species exclusively for the good of another species; though throughout nature one species incessantly takes advantage of, and profits by, the structure of another. But natural selection can and does often produce structures for the direct injury of other species, as we see in the fang of the adder, and in the ovipositor of the ichneumon, by which its eggs are deposited in the living bodies of other insects. If it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species, it would annihilate my theory, for such could not have been produced through natural selection.
    – Charles Darwin – Origin of Species

    Yet, contrary to this “Natural selection cannot possibly produce any modification in any one species exclusively for the good of another species” falsification criteria, time after time we find organisms helping each other, and us, in ways that have nothing to with their own ‘survival of the fittest’’ concerns.

    The following researchers said they were ‘banging our heads against the wall’ by the contradictory findings to Darwinian ‘survival of the fittest’ thinking that they had found:

    Doubting Darwin: Algae Findings Surprise Scientists – April 28, 2014
    Excerpt: One of Charles Darwin’s hypotheses posits that closely related species will compete for food and other resources more strongly with one another than with distant relatives, because they occupy similar ecological niches. Most biologists long have accepted this to be true.
    Thus, three researchers were more than a little shaken to find that their experiments on fresh water green algae failed to support Darwin’s theory — at least in one case.
    “It was completely unexpected,” says Bradley Cardinale, associate professor in the University of Michigan’s school of natural resources & environment. “When we saw the results, we said ‘this can’t be.”‘ We sat there banging our heads against the wall. Darwin’s hypothesis has been with us for so long, how can it not be right?”
    The researchers ,,,— were so uncomfortable with their results that they spent the next several months trying to disprove their own work. But the research held up.,,,
    The scientists did not set out to disprove Darwin, but, in fact, to learn more about the genetic and ecological uniqueness of fresh water green algae so they could provide conservationists with useful data for decision-making. “We went into it assuming Darwin to be right, and expecting to come up with some real numbers for conservationists,” Cardinale says. “When we started coming up with numbers that showed he wasn’t right, we were completely baffled.”,,,
    Darwin “was obsessed with competition,” Cardinale says. “He assumed the whole world was composed of species competing with each other, but we found that one-third of the species of algae we studied actually like each other. They don’t grow as well unless you put them with another species. It may be that nature has a heck of a lot more mutualisms than we ever expected.
    “,,, Maybe Darwin’s presumption that the world may be dominated by competition is wrong.”


    We are living in a bacterial world, and it’s impacting us more than previously thought – February 15, 2013
    Excerpt: We often associate bacteria with disease-causing “germs” or pathogens, and bacteria are responsible for many diseases, such as tuberculosis, bubonic plague, and MRSA infections. But bacteria do many good things, too, and the recent research underlines the fact that animal life would not be the same without them.,,,
    I am,, convinced that the number of beneficial microbes, even very necessary microbes, is much, much greater than the number of pathogens.”

    Plant Galls and Evolution
    How More than Twelve Thousand1 Ugly Facts are Slaying a Beautiful Hypothesis: Darwinism2
    Wolf-Ekkehard Lönnig – 7 September 2017
    Excerpt: in the case of the galls, in thousands of plant species often entirely new organs have been formed for the exclusive good of more than 132,930 other species, these ‘ugly facts’ have annihilated Darwin’s theory as well as the modern versions of it. The galls are not ‘useful to the possessor’, the plants. There is no space for these phenomena in the world of “the selfish gene” (Dawkins). Moreover, the same conclusion appears to be true for thousands of angiosperm species producing deceptive flowers (in contrast to gall formations, now for the exclusive good of the plant species) – a topic which should be carefully treated in another paper.

  4. 4
    Fasteddious says:

    This is a form of suspended animation. Perhaps scientists could study how these bacteria do it, and thereby get a few hints about how it might be done in higher life forms. True suspended animation would be a major boon for interstellar travellers, as assumed in numerous science fiction tales. Perhaps even for interplanetary travel.

Leave a Reply