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How often do you really consider bacteria? These minuscule organisms dominate life on Earth, and some scientists believe their potential is staggering. Our tiny, single-celled companions possess a wide range of astonishing abilities and applications—like producing gold or brewing alcohol. The world of microbes is both strange and captivating, without a doubt. Here are ten of the most remarkable scientific discoveries and experiments related to these microscopic wonders.
10. The Microbe That Produces Gold
Cupriavidus metallidurans is an incredibly unusual microbe. This tiny bacterium absorbs metal compounds and effectively excretes gold nuggets.
This strange behavior is a result of C. metallidurans' interaction with its environment. The soil it inhabits contains toxic minerals such as copper and gold. While both metals are hazardous in large amounts, copper is vital for the survival of the microbe. Therefore, the bacterium absorbs minerals from the soil and transforms them into a safer, less harmful form.
When there is an excess of gold, C. metallidurans produces an enzyme named CopA to prevent the absorption of harmful compounds. "This ensures fewer copper and gold compounds enter the cell's interior," said Professor Dietrich H. Nies.
"The bacterium is less poisoned, and the enzyme that expels copper can eliminate the excess copper without obstruction. Another effect: the gold compounds that are hard to absorb are transformed into harmless gold nuggets just a few nanometers in size on the cell's surface," explained Nies.
9. Bacteria Over 100 Million Years Old Found Beneath the Ocean Floor
In July 2020, researchers announced that they had successfully retrieved bacteria from the Pacific Ocean's seafloor, believed to be over 100 million years old. These microbes are considered the oldest known living organisms on Earth.
These extraordinary microbes belong to ten major bacterial groups and have remained dormant over 200 feet (70 meters) beneath the ocean floor. Samples of clay were collected by the international research vessel JOIDES Resolution, where the bacteria were uncovered under the seabed.
After millions of years without nutrients, scientists were astonished to discover that 99% of the microbes had survived. The researchers then incubated the organisms in a lab for 557 days, providing them with nourishment such as carbon and nitrogen sources like ammonia, acetates, and amino acids.
8. Hostile Behavior Toward Lazy Colony Members
It may sound strange, but evidence suggests that bacteria can act spitefully when their fellow microbes refuse to contribute. In some cases, these angry microbes deliberately harm themselves as a way to punish the idle members of the colony.
As detailed in a 2022 study published in PLOS Computational Biology, bacterial colonies rely on producing essential chemicals, like enzymes, to break down food into nutrients. The quantity they produce is regulated by a behavior called quorum sensing. When bacteria sense many of their peers nearby, they reduce their enzyme production. However, some lazy bacteria refuse to produce enzymes and instead try to benefit from the work of others.
In this situation, the researchers were shocked to find that the other bacteria also reduced their chemical output. As a result, no microbe has enough to eat, and the entire colony may eventually perish. As the researchers described it, the microbes essentially engage in "evolutionary suicide" to eliminate their freeloading peers.
"We didn’t anticipate this kind of behavior, which could even be described as 'spiteful,'" said Dr. Andrew Eckford, one of the lead authors of the study. "But it shows that quorum sensing is an incredibly adaptable mechanism for ensuring fairness."
7. 2,000 Generations of Bacteria Provide Insights Into a Scientific Dilemma
Evolution is a captivating process. It's the reason we are here today, rather than just existing as simple, single-celled organisms in the water. Yet, it remains somewhat of an enigma.
How much of evolution is shaped by the diversity within the gene pool, and how much is driven by random mutations? It's an age-old biological debate. But with the help of bacteria, scientists at Michigan State University may be one step closer to unraveling the mystery.
Over the course of a year, the researchers bred more than 2,000 generations of E. coli bacteria. The bacteria were divided into 72 groups, each with varying levels of genetic diversity. The team observed their ability to compete for nutrients at different stages. After 50 generations, populations with higher genetic diversity had a distinct advantage. However, by the 500th generation, genetic mutations had diminished the differences between the groups, making them irrelevant. This finding adds a new perspective to the ongoing debate about evolution.
6. Microbes in the Gut Produce Their Own Alcohol
For years, scientists have warned about the harmful effects of alcohol on our internal organs. However, in 2019, researchers in Beijing discovered a microbe living in the gut that produces alcohol in large quantities.
The alcohol-producing bacterium was first found in a patient with a rare condition called auto-brewery syndrome (ABS). Individuals with ABS can get drunk after consuming sugar. This condition is often caused by an overgrowth of yeast in the intestines, but in this case, the scientists identified a "super-strain" of bacteria.
The microbe responsible is Klebsiella pneumoniae, and there is evidence linking it to fatty liver disease in individuals who don't drink alcohol. Although more research is needed, the scientists emphasize that understanding the cause of a medical condition opens the door for potential treatments.
5. A Cure for Gluten Intolerance or Proof of Extraterrestrial Life?
In October 2022, researchers revealed that they had uncovered potentially groundbreaking bacterial strains deep within a cave hundreds of meters below ground. Why is this discovery so significant? The team—comprised of scientists from the USA, Algeria, and Sweden—believes these bacteria could hold the key to treating gluten intolerance.
"We discovered strains capable of producing antimicrobial substances or breaking down gluten, a compound that causes inflammatory reactions in the intestines of many people," said Natuschka Lee. "The bacteria were also found to be resilient enough to survive the harsh conditions of the human digestive system."
But that's not all. The discovery of bacteria in an underground cave highlights life’s ability to endure even in the most extreme environments—dark, isolated, and nutrient-deprived. Scientists believe this points to the possibility of microbial life hidden beneath the surface of Mars.
4. Eyelash-Sized Bacteria Is the Largest Ever Found
While most bacteria are just a fraction of a micrometer in size, the largest ever discovered is visible to the naked eye. Found on mangrove leaves in a swamp in Guadeloupe, Thiomargarita magnifica challenges the scientific understanding of the maximum size a microbe can attain. Their models suggest no microbe should grow that large, yet here it is, proving that life will always find a way.
"Imagine encountering another human who stood as tall as Mount Everest," said Jean-Marie Volland, co-author of the study.
In addition to its massive size, T. magnifica boasts several unique characteristics. While most bacteria have their DNA freely floating inside the cell, this giant strain organizes its genetic material within compartments. Moreover, it has three times the number of genes, with an extensive array of complex genome copies spread throughout the cell.
However, the biggest mystery for scientists is how bacteria are able to grow to such an astonishing size.
3. The Fight Against Cancer
Cancer remains one of the most destructive and deadly diseases in the world today. While remarkable progress has been made in the battle against it, there is still a long journey ahead.
Picture a future where cancer could simply be "switched off." In March 2023, immunologists at Columbia University proposed the revolutionary idea of using bacteria as a potential cancer treatment. By genetically altering these bacteria, they could infiltrate tumors and activate the immune system by releasing chemokine proteins.
Different chemokines provoke varying responses from the immune system. In a mouse trial, the bacteria were engineered to draw in T-cells—cells that target tumors—and dendritic cells, which assist T-cells in accurately attacking cancer.
"My graduate student, Thomas [Savage], came up with the idea of using this platform to deliver chemokines," said Dr. Nicholas Arpaia, the study's author. "Through years of research that has helped us understand how immune responses develop, we are creating therapies that specifically target each step of this process."
2. Scientists Teach Microbes to Play Tic-Tac-Toe
Thanks to the efforts of researchers at the Spanish National Research Council, you can now challenge genetically modified bacteria to a game of tic-tac-toe.
A European team taught a strain of E. coli to play tic-tac-toe in a groundbreaking yet bizarre experiment. They altered the bacteria to function like brain synapses, creating 'neural networks' from these tiny organisms.
As synthetic biologist Alfonso Jaramillo explained to New Scientist, this unusual experiment demonstrates that the bacteria behave similarly to an electronic component called a memristor, which is being used in computer chips designed to mimic brain synapses. Though it sounds strange, the team believes this development could pave the way for future applications such as smart microbiomes or living materials.
1. Mining for Rare Earth Elements
Bacteria might be better at mining rare earth elements than humans. Researchers from Penn State University suggest that a protein called lanmodulin could play a crucial role in resource extraction and green technologies.
Rare earth elements are some of the most crucial materials in modern society. From smartphone components to electric vehicles, metals like neodymium and dysprosium—though lesser-known—are essential. Neodymium, in particular, is critical for creating powerful magnets when added to iron.
Currently, these materials are difficult and costly to extract. This is where microbes play a crucial role. Lanmodulin, a protein produced by methylotroph bacteria, binds to specific rare-earth metals with extraordinary strength—100 million times stronger than its attachment to other metals. The research team at Penn State aims to harness this unique bonding ability to transform the process of producing rare earth metals in a cleaner way.
