Sunday, October 09, 2022

How dormant bacteria monitor the environment and come back to life even after one hundred million years

Amazing stuff!

"... In one extreme case, researchers in the US and Japan found deep-sea microorganisms that had laid dormant for more than 100 million years. When the extracted microbes were studied in the lab, researchers found the bacteria started to grow even though they were deposited during a time when dinosaurs were still alive.
Dormant bacteria, known as spores, aren’t just able to come back to life after a long time, they can withstand extreme pressure, temperature, and even outer space. ...
What if we resurrect a dormant highly dangerous pathogen ...
biologists at the University of California San Diego, who found spores retain the ability to evaluate their surrounding environment by using stored electrochemical energy, which works a lot like an electrical capacitor.
“... spores, which were considered to be inert objects,” ... “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 researchers found that the microbes could detect small environmental inputs, such as fluxes of potassium ions. If the sum of these signals exceeded a certain threshold, the spores would exist their dormant state and resume biological activity. ..."

From the abstract:
"Sparse microbial populations persist from seafloor to basement in the slowly accumulating oxic sediment of the oligotrophic South Pacific Gyre (SPG). The physiological status of these communities, including their substrate metabolism, is previously unconstrained. Here we show that diverse aerobic members of communities in SPG sediments (4.3‒101.5 Ma) are capable of readily incorporating carbon and nitrogen substrates and dividing. Most of the 6986 individual cells analyzed with nanometer-scale secondary ion mass spectrometry (NanoSIMS) actively incorporated isotope-labeled substrates. Many cells responded rapidly to incubation conditions, increasing total numbers by 4 orders of magnitude and taking up labeled carbon and nitrogen within 68 days after incubation. The response was generally faster (on average, 3.09 times) for nitrogen incorporation than for carbon incorporation. In contrast, anaerobic microbes were only minimally revived from this oxic sediment. Our results suggest that microbial communities widely distributed in organic-poor abyssal sediment consist mainly of aerobes that retain their metabolic potential under extremely low-energy conditions for up to 101.5 Ma."

From the 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."

How dormant bacteria come back to life even after millions of years of 'slumber' New research found spores can count environmental signals without expending metabolic energy, constantly monitoring for the right time to awaken.

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