Buzz
Bacteria, our ancient microbial relatives, coexist with humans on Earth, thriving in diverse habitats and performing essential roles—some beneficial, others harmful. Interestingly, it might be more accurate to say bacteria graciously share the planet with us, given their staggering population of approximately 5×10^30, collectively outweighing all plant and animal life combined.
While we often associate bacteria with familiar environments like our digestive systems, kitchens, forests, and ponds, many species thrive in unconventional and astonishing locations, both on Earth and beyond.
10. Deep Within Solid Rock
For centuries, sunlight was considered essential for life to thrive. Even organisms not directly reliant on the Sun, like those in the human gut, depend on organic matter originally produced through photosynthesis.
However, this long-held belief has recently been challenged. Researchers exploring a South African gold mine uncovered bacteria living more than 1.5 miles underground, surviving entirely on radioactive materials.
The uranium, thorium, and potassium in the surrounding rocks emit just enough radiation to split water molecules, generating hydrogen peroxide and sulfates. This process releases hydrogen and oxygen atoms, which react with other water molecules to form hydrogen peroxide. The hydrogen peroxide then interacts with pyrite (fool’s gold), producing sulfate ions that serve as a primary food source for these resilient bacteria.
These isolated microbes show no urgency to abandon their subterranean home. Unlike common bacteria such as E. coli, which reproduce daily, these rock-dwelling organisms may divide only once a year or as infrequently as once every 300 years.
9. The Most Sterile Environment on Earth: NASA’s Clean Rooms
After a deep cleaning of your kitchen or bathroom, you might feel a sense of accomplishment, knowing you’ve eradicated most microbes. Now, picture working at NASA, where your responsibility is to maintain the pristine condition of their “clean rooms.” These spaces require staff to wear triple-layered, sterilized suits, as NASA demands an unparalleled level of cleanliness.
According to Mike Weiss, Hubble’s technical deputy program manager at Goddard, these rooms are akin to “hospital operating rooms for patients.” He explains, “Surgeons use sterile gowns, gloves, and masks during procedures to ensure a germ-free environment for patients. For us, the spacecraft is the patient, and maintaining sterility is critical.”
Entry into these facilities requires passing through multiple “lobbies.” The first lobby uses specialized adhesive to strip dirt particles from shoes, the second subjects entrants to a high-pressure air shower, and the third mandates full-body protective gear from head to toe.
This meticulous process made it particularly surprising when a completely new bacterial genus, Tersicoccus phoenicis (with “Tersi” meaning clean in Latin), was discovered in not just one, but two NASA clean rooms. This bacterium has gained notoriety for resisting even the most rigorous cleaning and sterilization methods.
NASA scientists maintain samples of this hardy bacterium to compare it with any microorganisms potentially retrieved from space.
8. Frozen Ice Sheets
Ice often evokes thoughts of cold, stillness, and a lack of life. We use freezers for long-term food storage not just to save space but to inhibit the chemical processes that lead to spoilage.
This makes it even more astonishing that vast bacterial communities thrive within some of the planet’s largest glaciers, with certain strains surviving for millions of years.
The Transantarctic Mountains in Antarctica hold the oldest ice on Earth, harboring microbes that have persisted for millions of years. The microbial population trapped in Antarctic ice is estimated to exceed the global human population by over 10,000 times.
As global temperatures rise and ice melts, these ancient microbes could soon be released into the ocean, where they’ll face the challenge of adapting to a new and potentially more favorable environment.
7. Boiling Water
Every scout knows that boiling natural water sources is essential to eliminate harmful bacteria. However, this method isn’t foolproof, as certain bacteria, like Clostridium botulinum, can withstand boiling temperatures.
Clostridium botulinum, the bacterium behind botulism—a severe paralytic illness caused by a nerve toxin entering the body through food or wounds—thrives in low-oxygen environments. This allows it to survive in unsettling places, such as camping kettles or sealed cans.
Given that botulism often requires intensive antibody therapy and hospitalization, it’s crucial to use bleach, sodium hydroxide, and extremely high temperatures (around 120 degrees Celsius) to effectively eliminate this resilient bacterium.
6. The Deepest Point on Earth
Ocean enthusiasts are well aware that the Mariana Trench is one of the most enigmatic locations in the ocean, if not the entire planet. Situated east of the Philippines and north of New Guinea, it is the deepest part of any ocean, reaching depths of approximately 11,000 meters. For years, oceanographers have sought to discover new life forms in this dark, largely inaccessible abyss. Recently, in the Challenger Deep—the trench’s lowest point—researchers identified heterotrophic bacteria that survive by feeding on organic particles drifting down from above.
Bacteria residing in the ocean beyond the reach of sunlight (starting around 100 meters deep) rely on breaking down compounds like sulfur and ammonia for survival, making the discovery of these heterotrophic bacteria even more intriguing.
5. The Earth’s Upper Atmosphere
While bacteria are typically associated with living alongside or feeding on organic matter within the animal kingdom, a significant microbial population has recently been detected in the Earth’s upper atmosphere, challenging this conventional understanding.
Despite the absence of life forms in the atmosphere to feed on, these airborne bacteria thrive on abundant carbon, sustaining themselves even at altitudes exceeding six miles above sea level. Remarkably, bacteria may constitute approximately 20 percent of the tiny particles in the upper atmosphere at any given moment.
While the exact mechanism of how these bacteria reached such heights remains unclear, scientists theorize that powerful winds and shifting atmospheric pressures propelled them skyward, similar to how salt and dust particles are carried into the air.
4. The Human Eyeball
It’s widely known that the human body hosts a vast number of bacteria—more bacterial cells than human cells, in fact. We often imagine these beneficial microbes residing harmoniously in our gut, supporting digestion and extracting maximum energy from our food as part of a symbiotic relationship.
However, we tend to overlook the fact that more harmful bacteria, such as Chlamydia trachomatis and Neisseria gonorrhoeae, inhabit the conjunctiva—the mucous membrane covering the eyeball. Despite our tears’ efforts to combat these bacteria with enzymes like lysozyme, they remain a persistent presence.
These bacteria are the same ones responsible for chlamydia and gonorrhea infections, respectively. Keeping your eyes clean is essential.
3. The Dead Sea
Despite its name, the Dead Sea isn’t entirely devoid of life. While its hypersaline waters are hostile to most organisms, certain bacteria have adapted by thriving in freshwater springs found within the sea.
In the past decade, scientists have identified new bacterial life forms at the Dead Sea’s depths. These bacteria have evolved to tolerate both extreme salinity and freshwater, a crucial adaptation given the sea’s rapidly fluctuating salt levels.
These prokaryotic bacteria cling to rocks on the seabed, where underwater craters release freshwater and sulfides, creating a thin white film. This discovery challenges the belief that bacteria can only survive in either freshwater or saltwater environments, not both.
2. The Glabella
The glabella, the smooth area between your eyebrows and above your nose, might seem an unlikely habitat for bacteria due to its exposure. Yet, this doesn’t deter the peculiar-looking Demodex folliculorum (eyelash mites), which roam your forehead in search of carbon-based nutrients. Alongside the more familiar Propionibacteria, these microbes are usually harmless but can sometimes trigger infections like acne vulgaris. Next time a pimple appears between your eyes, you know who to blame.
1. Antarctica
Seafood enthusiasts often hear warnings about excessive fish consumption due to mercury concerns. A key contributor to mercury in fish may be a newly identified Antarctic bacterium called Nitrospinia. This microbe specializes in converting mercury into methylmercury, a more toxic form linked to developmental issues in children. Once ingested and transformed, these bacteria are eaten by various fish, eventually making their way to your plate.
With many popular fish dishes originating from the Southern Ocean, this poses a significant issue for seafood lovers, especially as commercial fishing expands southward in response to dwindling fish stocks.
