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Unusual Bacteria: Strange Facts About Fascinating Microbes

Linda Crampton has an honors degree in biology and many years of teaching experience. She finds the study of microorganisms fascinating.

Grand Prismatic Spring, Yellowstone National Park: the orange area is made of thermophilic microbes that contain orange pigments called carotenoids.

Grand Prismatic Spring, Yellowstone National Park: the orange area is made of thermophilic microbes that contain orange pigments called carotenoids.

Interesting and Diverse Organisms

Bacteria are fascinating microbes. Many people think of them as simply causers of disease. While it's true that some of them can make us sick, many are harmless or even beneficial. Researchers are discovering that some bacteria have amazing abilities that are interesting in their own right and may be helpful to humans in the future.

Although most bacteria are made of a single microscopic cell, they are not as simple as was previously believed. The organisms can communicate with each other via the release and detection of chemicals and can coordinate their actions. Some can survive in extreme environmental conditions that would kill humans; some can produce light or electricity; and some can detect and respond to magnetic fields. Several kinds are predators that attack other bacteria.

This article describes unusual features of some of the known bacteria. As scientists explore nature, they are finding new bacteria and learning more about the previously identified ones. They may soon discover many more surprising facts about the microbes in our world.

This is a colourized photo of Escherichia coli (E. coli). Some strains of this bacterium make us sick, and others make useful substances in our intestine.

This is a colourized photo of Escherichia coli (E. coli). Some strains of this bacterium make us sick, and others make useful substances in our intestine.

Studies have shown that bacteria fall into two distinct groups, based on their different characteristics. These groups are known as the kingdoms Eubacteria and Archaebacteria or as the domains Bacteria and Archaea. In the latter classification scheme, archaeons (members of the Archaea domain) aren't considered to be bacteria. They are fascinating organisms, however. I discuss some of them in this article.

Extremophiles: Living in Extreme Environmental Conditions

Some bacteria live in extreme environments and are known as extremophiles. "Extreme" environments (by human standards) include those with a very high or very low temperature, those with a high pressure, salinity, acidity, alkalinity, or radiation level, or those with no oxygen.

Microbes known as archaeons frequently live in extreme conditions. Archaeons look similar to bacteria under a microscope, but they are very different genetically and biochemically. They are often referred to as bacteria, but most microbiologists feel that this term is inaccurate.

Thermophilic bacteria live around the Champagne Vent in the Marianas Trench.

Thermophilic bacteria live around the Champagne Vent in the Marianas Trench.

Examples of Extremophiles

  • Halophilic bacteria live in salty environments.
  • Salinibacter ruber is a rod-shaped, orange-red bacterium that grows best when it's living in ponds that contain 20% to 30% salt. (Seawater contains about 3.5% salt by weight.)
  • Some halophilic archaeons survive very well in water that is almost saturated with salt, such as the Dead Sea, salt lakes, natural brines, and pools of evaporating sea water. Dense populations of archaeons may develop in these habitats.
  • Halophilic archaeons often contain pigments called carotenoids. These pigments give the cells an orange or red color.
  • Thermophilic bacteria live in hot environments
  • Hyperthermophilic bacteria live in extremely hot environments that have a temperature of at least 60°C (140°F). The optimal temperature for these bacteria is greater than 80°C (176°F).
  • Bacteria living around hydrothermal vents in the ocean require a temperature of at least 90°C (194°F) in order to survive. A hydrothermal vent is a crack in the Earth's surface from which geothermally heated water emerges.
  • Some archaeons survive around deep-water vents at a temperature of greater than 100°C (212°F). The high pressure prevents the water from boiling.
  • In 2013, scientists discovered a bacterium called Planococcus halocryophilus (OR1 strain) living in permafrost in the High Arctic. The bacterium was reproducing at -15°C —a low-temperature record so far—and was able to survive at -25°C.
  • Deinococcus radiodurans, sometimes called "the world's toughest bacterium", can survive cold, acid, dehydration, a vacuum, and radiation a thousand times stronger than a human can withstand.

Bioluminescence: Producing Light

Bioluminescent bacteria are found in sea water, in sediments on the ocean bottom, on the bodies of dead and decaying marine animals, and inside ocean creatures. Some marine animals have specialized light organs that contain bioluminescent bacteria.

The Flashlight Fish

A flashlight fish is an interesting example of an animal containing luminescent bacteria. There are a number of different kinds of flashlight fish, all belonging to the same family (the Anomalopidae). The animals have a bean-shaped light organ, or photophore, below each eye. The light from the organ turns on and off like a flashlight.

In some fish, the light is "turned off" by a dark membrane that covers the photophore and is turned on again when the membrane is removed. The action of the membrane resembles that of an eyelid. In other fish, the photophore is moved into a pocket in the eye socket to hide the light.

Function of the Light

The flashlight fish is nocturnal. It uses its light to communicate with other fish and to attract prey. The light also helps the fish to avoid predators. The predators are often confused by the light turning on and off and find it difficult to locate the fish as it changes direction in the water.

Method of Light Production

The light is produced by bacteria living in the light organ. The bacteria contain a molecule called luciferin, which releases light when it reacts with oxygen. An enzyme called luciferase is necessary for the reaction to happen. The bacteria benefit from living in the light organ by receiving nutrients and oxygen from the fish's blood.

Flashlight Fish With Bioluminescent Bacteria

The flashlight fish in the video above is named Photoblepharon palpebratus. It's often known as the eyelight fish.

Bacterial Communication and Quorum Sensing

Bacteria communicate with each other via the transmission of signaling molecules between different cells. Signaling molecules are chemicals that are produced by bacteria and bind to receptors on the surface of other bacteria, triggering a response in the ones that receive the chemicals.

Researchers are discovering that many bacterial species are able to detect the amount of a specific signaling molecule that is present in their environment in a process called quorum sensing. The species respond to a chemical signal only when the concentration of the molecule reaches a specific level.

If only a few bacteria are present in an area, the level of the signaling molecule is too low and the bacteria don't respond to its presence. If a sufficient number of bacteria are present, however, they produce enough of the molecule to trigger a specific response. All the bacteria then respond in the same way at the same time. The bacteria indirectly detect their population density and change their behaviour when a "quorum" is present.

Quorum sensing allows bacteria to coordinate their actions and produce a stronger effect on their environment. For example, pathogenic bacteria (ones that cause disease) often have an improved ability to attack the body when they coordinate their behaviour.

The Hawaiian Bobtail Squid (Euprymna scolopes)

Quorum Sensing in a Luminescent Bacterium

The Hawaiian bobtail squid has an interesting use for luminescent bacteria. The tiny squid is only one or two inches long. It's nocturnal and spends the night buried in sand or mud. At night, it becomes active and feeds mainly on small crustaceans, such as shrimp. The squid has a light organ in the lower part of its body that contains a bioluminescent bacterium called Vibrio fischeri. This is the only species of bacteria that has been found in the organ.

The bacterial cells produce a signaling molecule known as an autoinducer. As the autoinducer accumulates inside the light organ, it eventually reaches a critical level that activates the luminescence genes of the bacteria. The process is an example of quorum sensing.

The light emitted by the bacteria helps to prevent the squid's silhouette from being seen by predators swimming below the squid. The light from the photophore matches the light reaching the ocean from the moon in both brightness and wavelength, camouflaging the squid. This phenomenon is known as counter-illumination.

In the morning, the squid carries out a process called venting. Most of the bacteria in the photophore are released into the ocean. Those that are left reproduce. When night arrives, the bacterial population is once again sufficiently concentrated to produce light. The daily venting means that the bacteria never become so numerous that they can't obtain enough food and energy for light production.

Bacteria in the Hawaiian Bobtail Squid Light Organ

Both the bacteria and the squid benefit from their relationship. The squid is camouflaged when it's active. The bacteria use amino acids and sugars in the light organ as food. They are also protected while they are inside the squid.

Predatory Bacteria

Predatory bacteria attack and kill other bacteria. Researchers are discovering that they are widespread in aquatic habitats and in soil. Two examples of the bacteria are described below.

  • Vampirococcus lives in freshwater lakes with a high sulphur content. It attaches to a much larger, purple bacterium called Chromatium and absorbs the liquid from its prey, killing it. This process reminded early researchers of a vampire sucking blood and gave them the idea for the bacterium's name.
  • Unlike Vampirococcus, Bdellovibrio bacteriovorus attaches to another bacterium and then enters it instead of staying on the outside. It produces enzymes to digest the outer covering of its prey and also rotates, allowing it to drill its way into the prey.
  • Bdellovibrio reproduces inside its prey.and then destroys it.
  • The predator can swim at the amazing rate of 100 cell lengths a second, making it one of the fastest-moving of all known bacteria.

Some researchers are investigating the possibility that predatory bacteria could be used to attack bacteria that are harmful to humans. This ability could be very useful, provided the predators don't attack us as well.

Bdellovibrio Attacks E. coli

Detecting and Responding to Magnetic Fields

Scientists didn't realize that certain bacteria could detect magnetic fields until a 1975 discovery by Richard P. Blakemore, a scientist at Woods Hole Oceanographic Institution. Magnetic bacteria, also called magnetotactic bacteria, detect and respond to the Earth's magnetic field (or to the field created by a magnet placed near them).

  • Blakemore noticed that some bacteria always moved to the same side of the slide when he was observing them under a microscope.
  • He also observed that if he placed a magnet next to a slide, certain bacteria always moved towards the north end of the magnet.
  • Magnetic bacteria contain special organelles called magnetosomes.
  • Magnetosomes contain either magnetite or greigite, which are magnetic crystals.
  • Each magnetic crystal is a tiny magnet that has a north pole and a south pole, just like other magnets.
  • Since magnets are attracted to each other via their opposite poles, the magnetic crystals in the bacteria are attracted to the Earth's magnetic field.

As in the case of predatory bacteria, scientists are investigating ways in which the magnetic properties of bacteria might help humans.

Bacteria Moving in Response to a Magnet

Creating Electricity

The list of bacteria known to produce an electric current (or a flow of electrons) is growing. In 2018, scientists found that even some of the bacteria living in our gut can do this, though the current is too weak to hurt us. Before this discovery, it was thought that only certain bacteria living in environments such as caves and deep lakes were electrogenic, or capable of producing an electric current.

Bacteria, plants, and animals (including humans) produce electrons during metabolic reactions. In plants and animals, the electrons are accepted by oxygen in the mitochondria of cells. Bacteria that live in environments with a low oxygen content need to find another way to get rid of the particles. In some places, a mineral in the environment absorbs the electrons. In the newly discovered process that occurs in gut bacteria, a molecule called flavin seems to be essential for the flow of electrons.

As might be expected, scientists are investigating bacteria that emit an electric current in the hope that they can help us. The exploration of electricity production by intestinal bacteria may also be helpful.

Future Research About Intriguing Creatures

Bacteria are tiny organisms and live in many different habitats. Some of these habitats are inhospitable to humans or difficult for us to explore. It's possible that there are amazing abilities of bacteria still to be discovered and that some of these abilities may improve our lives. The bacterial species that are known have already provided us with surprises and impressive information. The results of future research should be very interesting.


Questions & Answers

Question: Is Nostoc luminescent?

Answer: Nostoc is a genus of organisms known as cyanobacteria. Cyanobacteria were once known as blue-green algae. Nostoc has some interesting features, but I’ve never heard of any luminescent species in the genus.

© 2013 Linda Crampton


Linda Crampton (author) from British Columbia, Canada on October 08, 2013:

Thank you very much for the kind comment, jonnycomelately! The book that you've mentioned sounds interesting. I'll look out for it.

jonnycomelately on October 08, 2013:

AliciaC , this is a wonderful hub! Apart from it having inspired many of your readers who have hitherto known little of bacterial "business," it is obviously also interesting to others who are more deeply involved.

I find it particularly interesting, in relation to my work with composting toilets. (Research "The Humanure Handbook" by Joseph Jenkins.)

The need to allow and aid biodiversity in compost heaps, in order for the composting to "work" well, is paramount.

Linda Crampton (author) from British Columbia, Canada on October 08, 2013:

Thank you, DDE. I appreciate your comment.

Devika Primić from Dubrovnik, Croatia on October 08, 2013:

Unusual Bacteria - Strange Facts About Fascinating Microbes, an interesting hub on this topic and well done on your great achievement

Linda Crampton (author) from British Columbia, Canada on July 04, 2013:

Hi, thumbi7. I'm glad that this hub is useful for you! I hope your daughter gets into the college of her choice. Thank you for the comment.

JR Krishna from India on July 04, 2013:

Very informative and detailed article on bacteria.

Some of the facts are really new to me. It is very timely and useful to me as I am preparing my daughter for college entrance examination.

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Thank you very much, Erin. I agree - bacteria are very interesting!

Erin Wilson from Michigan on July 03, 2013:

Thank you for presenting the article in a way that is both informative and fun to read. Bacteria are oh so interesting.

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Thanks for the visit and the comment, Rebecca, as well as the congratulations!

Rebecca Mealey from Northeastern Georgia, USA on July 03, 2013:

Goodness, how informative and thorough! You could get hired as a biology textbook writer...and congrats on HOTD~

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Hi, anatomynotes. You're so right - there is still a lot to learn about microbes! Thanks for commenting.

Edmund Custers on July 03, 2013:

It is interesting to read about the mutually beneficial relationships between bacteria and other organisms. We still have much to learn from microbes. Thanks!

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Thank you for the visit and the comment, queerlyobscure!

Cecil Wilde from Melbourne, Australia on July 03, 2013:

This is fascinating! I really enjoyed reading about all the interesting bacteria.

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Thank you for the congratulations and for such a wonderful comment, Rose! I appreciate your visit very much.

rose-the planner from Toronto, Ontario-Canada on July 03, 2013:

First of all congratulations on HOTD and secondly, WOW! This is an amazing, insightful article filled with valuable information about bacteria. It truly deserves the accolade of HOTD. Thank you for sharing. (Voted Up). -Rose

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Hi, DreamerMeg. Yes, although some bacteria are dangerous, others are very useful! Thanks for the visit.

DreamerMeg from Northern Ireland on July 03, 2013:

Very interesting. Bacteria are interesting creatures but we always think of them as causing disease but some can be very helpful.

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Thank you very much, Cynthia. I appreciate your support here and on my Facebook page!

CMHypno from Other Side of the Sun on July 03, 2013:

Congratulations on HOTD Alicia. Who knew that bacteria could be so fascinating? Thanks for all the great information.

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Thank you very much for such a lovely comment, jonnycomelately. It's very nice to meet you!

jonnycomelately on July 03, 2013:

Alicia, that is an awesome Hub. So well written, beautiful photos and videos, well presented. And you obviously are in love with your subject.

Thanks for bringing so much information into our lives.

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Thank you very much for the kind comment, Bill. I appreciate your support a great deal!

Bill Holland from Olympia, WA on July 03, 2013:

I love it when friends of mine get recognition. Congratulations on the Hub of the Day...well-deserved with this article.

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Thank you so much for the comment, Mary! I appreciate the vote and the share, too.

Linda Crampton (author) from British Columbia, Canada on July 03, 2013:

Thank you very much for the congratulations , Kawi! I appreciate your visit.

Mary Hyatt from Florida on July 03, 2013:

Congrats on your well deserving HOTD. It is so refreshing to see a HOTD that has real merit! You did a lot of research on this one, and your time and effort has resulted in a great Hub about unusual bacteria.

As a former Medical Technologist who worked with bacteria in humans, I learned a lot here today.

Voted UP and will certainly share.

Kawika Chann from Northwest, Hawaii, Anykine place on July 03, 2013:

Alicia Nicely done - very informative and to the point. I like the video and the little Hawaiian squid - I always speared it's grand daddy - never saw these little guys while diving. Great job, keep up the good work. Let me be one of the first to congratulate you - HOTD. Peace. Kawi.

Linda Crampton (author) from British Columbia, Canada on June 18, 2013:

Hi, pinto2011. Thanks for the visit and the comment. That's a good description of the role that bacteria play in our world!

Subhas from New Delhi, India on June 18, 2013:

Hi AliciaC! You have make this topic alive by writing a whole lot of info about bacteria. They are the actual invisible churner of this world.

Linda Crampton (author) from British Columbia, Canada on June 17, 2013:

Thank you very much, Sue. I appreciate the vote and the share!

Susan Bailey from South Yorkshire, UK on June 17, 2013:

Amazing! So much information I didn't know. Voted up and shared.

Linda Crampton (author) from British Columbia, Canada on June 16, 2013:

Hi, Martie. Thank you for the very kind comment. I appreciate it. I think that the living world is fascinating and I love to write about it at HubPages. I enjoy creating fiction and poetry, too. I don't help to keep HubPages in business, though!

Martie Coetser from South Africa on June 16, 2013:

Hi Alicia, first of all congratulations with your 100 score.

Secondly, I am totally speechless. This is an extremely interesting hub about unusual bacteria. They remind me of aliens, although aliens are a production of human imagination. So maybe human imagination is not so out of line with reality. And how can we blame people with phobic fears of bacteria. But now this is the opinion of a writer of fiction and not of a scientist.

Thank you for making this so easy to understand. Writers like you keep HubPages in business.

Linda Crampton (author) from British Columbia, Canada on June 16, 2013:

Hi, Elias. Yes, the extremophiles are fascinating. Their ability to survive and thrive in such hostile environments is amazing! Thank you for the comment.

Elias Zanetti from Athens, Greece on June 16, 2013:

Informative and well researched hub, Alicia. The extremophiles, in particular, are quite fascinating as they inhabit environments that are so extreme for any other form of life on the planet. Whenever I watch a documentary about such places it comes as no surprise that scientists most likely will discover some form of bacterial life thriving there.

Linda Crampton (author) from British Columbia, Canada on June 15, 2013:

Thank for the comment, Deb. I appreciate it!

Deb Hirt from Stillwater, OK on June 15, 2013:

This was pretty amazing. I was just on the plane that bacteria survived in the same temperatures that we do. Thanks for the enlightenment!

Linda Crampton (author) from British Columbia, Canada on June 15, 2013:

Thanks for the comment, moronkee. It's nice to meet you!

Moronke Oluwatoyin on June 15, 2013:

I never knew that bacteria could communicate with each other.

I really liked biology when I was in High school.

The information you presented is very useful.Thanks

Linda Crampton (author) from British Columbia, Canada on June 15, 2013:

Thank you so much for the comment, Bill! I appreciate the share, the pin and the vote, too.

Bill De Giulio from Massachusetts on June 15, 2013:

Hi Alicia. What a fascinating hub. I knew very little about bacteria and this is amazing. You have opened a whole new world to me, thanks so much for the education. Voted up, shared, pinned, etc....

Linda Crampton (author) from British Columbia, Canada on June 14, 2013:

Thank you very much, Seeker7. I appreciate your kind comment and your vote! I've always found the microscopic world to be fascinating, too. There is so much there to discover!

Helen Murphy Howell from Fife, Scotland on June 14, 2013:

What a fabulous hub Alicia! I've always had a great interest in the microscopic world and knew a little, but your excellent article has given me so much new information. In particular I loved the section on bacteria communcation - awesome!

The bacteria Vampirococcus sound like something from a sci-fi/horror movie, but fascinating nevertheless.

A really interesting and informative hub! Voted up!!

Linda Crampton (author) from British Columbia, Canada on June 14, 2013:

Hi, drbj. Bacteria are certainly amazing organisms! They do seem to be much more complicated than was originally thought. Thanks for the comment.

drbj and sherry from south Florida on June 14, 2013:

It seems, Alicia, that some types of bacteria may not be as simple as we once thought. Many of those you describe in this fascinating hub have amazing abilities. Who knew?

Linda Crampton (author) from British Columbia, Canada on June 14, 2013:

Thank you, Bill. I appreciate the fact that you are the first commenter on my hubs very much!!

Bill Holland from Olympia, WA on June 14, 2013:

That was really interesting, Alicia. Having taught science I knew about a couple of these things, but a great amount of it I did not. Thanks for the fun facts that I can use playing Trivia. :)