Cell biology Evolutionary biology Intelligent Design Irreducible Complexity

At Phys.org: The thinking undead: How dormant bacteria calculate their return to life

Spread the love

Facing starvation and stress conditions, some bacteria enter a dormant state in which life processes stop. Shutting down into a deep dormancy allows these cells, called spores, to withstand punishing extremes of heat, pressure and even the harsh conditions of outer space.

Eventually, when conditions become favorable, spores that may have been dormant for years can wake up in minutes and spring back to life.

The thinking undead: How dormant bacteria calculate their return to life
A microscopy image reveals several spores with their electrochemical potential color-coded according to the strength of the signal. Credit: Süel Lab—Kaito Kikuchi and Leticia Galera

Spores wake up by re-hydrating and restarting their metabolism and physiology. But until now scientists did not know whether spores can monitor their environment “in their sleep” without waking up. In particular it was not known how spores deal with vague environmental signals that do not indicate clearly favorable conditions. Would spores just ignore such mixed conditions or take note?

University of California San Diego biologists have solved this mystery in a new study published in the journal Science. Researchers in the School of Biological Sciences discovered that spores have an extraordinary ability to evaluate their surrounding environment while remaining in a physiologically dead state. They found that spores use stored electrochemical energy, acting like a capacitor, to determine whether conditions are suitable for a return to normal functioning life.

“This work changes the way we think about spores, which were considered to be inert objects,” said Gürol Süel, a professor in the Department of Molecular Biology. “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.”

Many bacterial species form spores—partially dehydrated cells surrounded by a resilient protective coat—as a survival strategy that allows them to remain dormant for thousands of years. Such a remarkable capability makes them a threat in the form of bacterial anthrax as well as a contamination hazard in medicine and the food industry.

Süel and his colleagues tested whether dormant Bacillus subtilis spores could sense short-lived environmental signals that were not strong enough to trigger a return to life. They found that spores were able to count such small inputs and if the sum reached a certain threshold, they would decide to exit the dormant state and resume biological activity.

Developing a mathematical model to help explain the process, the researchers discovered that spores use a mechanism known as integrate-and-fire, based on fluxes of potassium ions for appraising the surrounding environment. They found that spores responded to even short-lived favorable signals that were not enough to trigger an exit from dormancy. Instead of waking up, spores released some of their stored potassium in response to each small input and then summed consecutive favorable signals to determine if conditions were suitable for exiting. Such a cumulative signal processing strategy can reveal whether external conditions are indeed favorable, and prevents spores from “jumping the gun” into a world of unfavorable conditions.

“The way spores process information is similar to how neurons operate in our brain,” said Süel. “In both bacteria and neurons, small and short inputs are added up over time to determine if a threshold is reached. Upon reaching the threshold spores initiate their return to life, while neurons fire an action potential to communicate with other neurons.” Interestingly, spores can perform this signal integration without requiring any metabolic energy, while neurons are among the most energy-dependent cells in our bodies.

The researchers believe the new information about spores reframes popular ideas about cells in extremely dormant states that seem dead. Such findings hold implications for evaluating life on objects such as meteors as well as space missions seeking evidence of life.

“This work suggests alternate ways to cope with the potential threat posed by pathogenic spores and has implications for what to expect from extraterrestrial life,” said Süel, who holds affiliations with the San Diego Center for Systems Biology, BioCircuits Institute and Center for Microbiome Innovation. “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.”

Phys.org

This fascinating research presents yet another remarkable example of biochemical complexity with a functionality dependent upon environmental sensing, signal evaluation, operational feedback, managing stored resources, and survivability–all within a supposedly inert “spore.” I’ll call that evidence of intelligent design. Anyone else want to suggest that the origin of this mechanism seems more consistent with an unguided natural process?

6 Replies to “At Phys.org: The thinking undead: How dormant bacteria calculate their return to life

  1. 1
    bornagain77 says:

    Off topic: Caspian, being a physicist, I think you may be very interested to learn that,

    The Nobel Prize in Physics 2022 was awarded jointly to Alain Aspect, John F. Clauser and Anton Zeilinger “for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science”
    https://www.nobelprize.org/prizes/physics/2022/press-release/
    Excerpt: Entangled states – from theory to technology

    Alain Aspect, John Clauser and Anton Zeilinger have each conducted groundbreaking experiments using entangled quantum states, where two particles behave like a single unit even when they are separated. Their results have cleared the way for new technology based upon quantum information.

    The ineffable effects of quantum mechanics are starting to find applications. There is now a large field of research that includes quantum computers, quantum networks and secure quantum encrypted communication.

    One key factor in this development is how quantum mechanics allows two or more particles to exist in what is called an entangled state. What happens to one of the particles in an entangled pair determines what happens to the other particle, even if they are far apart.

    For a long time, the question was whether the correlation was because the particles in an entangled pair contained hidden variables, instructions that tell them which result they should give in an experiment. In the 1960s, John Stewart Bell developed the mathematical inequality that is named after him. This states that if there are hidden variables, the correlation between the results of a large number of measurements will never exceed a certain value. However, quantum mechanics predicts that a certain type of experiment will violate Bell’s inequality, thus resulting in a stronger correlation than would otherwise be possible.

    John Clauser developed John Bell’s ideas, leading to a practical experiment. When he took the measurements, they supported quantum mechanics by clearly violating a Bell inequality. This means that quantum mechanics cannot be replaced by a theory that uses hidden variables.

    Some loopholes remained after John Clauser’s experiment. Alain Aspect developed the setup, using it in a way that closed an important loophole. He was able to switch the measurement settings after an entangled pair had left its source, so the setting that existed when they were emitted could not affect the result.

    Using refined tools and long series of experiments, Anton Zeilinger started to use entangled quantum states. Among other things, his research group has demonstrated a phenomenon called quantum teleportation, which makes it possible to move a quantum state from one particle to one at a distance.

    “It has become increasingly clear that a new kind of quantum technology is emerging. We can see that the laureates’ work with entangled states is of great importance, even beyond the fundamental questions about the interpretation of quantum mechanics,” says Anders Irbäck, Chair of the Nobel Committee for Physics.

    Illustrations

    The illustrations are free to use for non-commercial purposes. Attribute ”© Johan Jarnestad/The Royal Swedish Academy of Sciences”.

    Illustration: The Nobel Prize in Physics 2022 (pdf)
    Illustration: Does colour exist when no one is watching? (pdf)
    Illustration: Entangled particles that never met (pdf)
    Illustration: Experimenting with Bell inequalities (pdf)

    Anton Zeilinger: “It’s probably one of the most beautiful theories ever invented”
    https://www.youtube.com/watch?v=epooR8ONrj4

    Related notes:

    Einstein vs quantum mechanics, and why he’d be a convert today – June 13, 2014
    Excerpt: In a nutshell, experimentalists John Clauser, Alain Aspect, Anton Zeilinger, Paul Kwiat and colleagues have performed the Bell proposal for a test of Einstein’s hidden variable theories. All results so far support quantum mechanics. It seems that when two particles undergo entanglement, whatever happens to one of the particles can instantly affect the other, even if the particles are separated!
    http://phys.org/news/2014-06-e.....today.html

    Not So Real – Sheldon Lee Glashow – Oct. 2018
    Excerpt: In 1959, John Stewart Bell deduced his eponymous theorem: that no system of hidden variables can reproduce all of the consequences of quantum theory. In particular, he deduced an inequality pertinent to observations of an entangled system consisting of two separated particles. If experimental results contradicted Bell’s inequality, hidden-variable models could be ruled out. Experiments of this kind seemed difficult or impossible to carry out. But, in 1972, Alain Aspect succeeded. His results contradicted Bell’s inequality. The predictions of quantum mechanics were confirmed and the principle of local realism challenged. Ever more precise tests of Bell’s inequality and its extension by John Clauser et al. continue to be performed,14 including an experiment involving pairs of photons coming from different distant quasars. Although a few tiny loopholes may remain, all such tests to date have confirmed that quantum theory is incompatible with the existence of local hidden variables. Most physicists have accepted the failure of Einstein’s principle of local realism.
    https://inference-review.com/article/not-so-real

    “hidden variables don’t exist. If you have proved them come back with PROOF and a Nobel Prize.
    John Bell theorized that maybe the particles can signal faster than the speed of light. This is what he advocated in his interview in “The Ghost in the Atom.” But the violation of Leggett’s inequality in 2007 (via Zeilinger) takes away that possibility and rules out all non-local hidden variables. Observation instantly defines what properties a particle has and if you assume they had properties before we measured them, then you need evidence, because right now there is none which is why realism is dead, and materialism dies with it.
    How does the particle know what we are going to pick so it can conform to that?”
    per Jimfit
    https://uncommondescent.com/philosophy/quantum-physicist-david-bohm-on-why-there-cannot-be-a-theory-of-everything/#comment-662358

  2. 2
    Caspian says:

    BA77 @1,
    Thanks for sharing this news release of the Nobel Prize in Physics. Quantum entanglement is certainly a rich, non-intuitive feature of reality, with implications in communication and computing that are just beginning to be realized.

  3. 3
    relatd says:

    Caspian at 2,

    Quantum states are being used right now in practical applications. It does not matter if the math has not been worked out. The goal is to use the quantum world and do experiments that lead to practical applications, which are occurring with more frequency. In some cases, experimenters are using knowledge gained from macro electronics or what is called “classical physics.” It is a combination of trial and error and observation. And invention to solve problems to move the field forward.

    https://www.sciencedaily.com/releases/2022/09/220929203718.htm

    https://scitechdaily.com/new-invention-triggers-one-of-quantum-mechanics-strangest-and-most-useful-phenomena/

  4. 4
    relatd says:

    Ba77,

    I strongly disgree with the following. It is called ‘jumping to conclusions’ before all of the experiments are completed.

    “Observation instantly defines what properties a particle has and if you assume they had properties before we measured them, then you need evidence, because right now there is none which is why realism is dead, and materialism dies with it.”

    The quantum world, just like the macro world, has rules. You don’t have to understand it all at once. You perform experiments, observe the results, perform more experiments and confirm the results. That’s how science is done. Too many people are obsessed with how “strange” the results are. So what? Once certain rules about the quantum world are established, you use those rules to build devices that exploit the quantum world.

  5. 5
    bornagain77 says:

    Caspian, “Quantum entanglement is certainly a rich, non-intuitive feature of reality,”

    Yes, it is ‘non-intuitive’. And as I am sure that you know, Einstein termed it ‘spooky action at a distance’.

    “I cannot seriously believe in it because the theory cannot be reconciled with the idea that physics should represent a reality in time and space, free from spooky action at a distance”
    – Einstein – In a letter to Max Born in 1947

    Interestingly, a year before he died, Einstein himself, (who was one of the ones who put forth hidden variables), honestly confessed.that he was “not able to find a way to explain the atomistic character of nature. My opinion is that … one has to find a possibility to avoid the continuum (together with space and time) altogether.”

    “I must confess that I was not able to find a way to explain the atomistic character of nature. My opinion is that … one has to find a possibility to avoid the continuum (together with space and time) altogether. But I have not the slightest idea what kind of elementary concepts could be used in such a theory.”
    — Albert Einstein – Einstein to David Bohm (1954) – Einstein from “B” to “Z” Springer, p. 151 – John Stachel
    https://books.google.com/books?id=OAsQ_hFjhrAC&pg=PA151#v=onepage&q&f=false
    (of note: This quote was stated by Einstein the year before he passed away, after 3 decades of trying “to find a way to explain the ‘atomistic character’ of nature”)

    Hmmm, what type of cause could possibly exist outside space and time?

    Colossians 1:17
    He is before all things, and in him all things hold together.

    2 Timothy 1:9
    ,,, which was given to us in Christ Jesus before time began.

  6. 6
    relatd says:

    Some of the thoughts posted here remind me of the problems discovered with the advent of aircraft reaching supersonic speed. In regular flight, referred to as sonic, the aircraft travels through the air like a person swimming through water. A famous book about this (OK, famous among those that work in aeronautics) is called Fluid Dynamics. Supersonic is also referred to as Mach One, so the aircraft is now traveling at the speed of sound or 10,000 feet per second.

    As it approaches Mach One, it begins to vibrate. The air molecules holding it aloft cannot move out of the way fast enough so airflow separation begins to occur. That means the aircraft is becoming uncontrollable at that speed. The wings are vibrating and lift is affected. If the pilot is not aware of this he can crash.

    One more thing. Even though the air molecules can’t move out of the way fast enough, it does not mean they’re not there. So as the aircraft continues to force itself forward, it generates a shock wave, and exposed surfaces experience heating. The faster you go, the higher the level of heating.

    This was realized during World War II. The Germans were able to delay the onset of vibration by employing what they called an ‘arrow wing’ or swept-back wing. This appeared on the Me 262 jet fighter and Ar 234 jet bomber.

    So, the quantum world is strange? No, it just has its own rules. I propose the following description: The quantum world is a transition between the atomic macro world and the very much smaller subatomic world. Once that boundary, and it is a boundary, is crossed, certain defined effects occur.

Leave a Reply