Endospores — The Eternal, Indestructible Shells of Bacteria
You’ve probably heard this at some point before, but some of the most extreme and survivable organisms on earth are certain forms of bacteria. Bacteria are not only highly survivable but they are so prolific that there are approximately 5,000,000,000,000,000,000,000,000,000,000 on Earth at any given time.
This is five million trillion trillion or 5 x 10 to the 30th power!
Just looking at that number is unfathomable, let alone attempting to count them, or get rid of them, or what not. Even if somehow earth were to be attacked by an advanced alien race with the ability to destroy the planet outright at its disposal, the bacteria would undoubtedly survive such an onslaught, since some are so hearty they could even survive in a vaacum indefinitely.
Bacteria are the indeed the alpha and the omega. They were here long before we got here, and they will be here long after we are gone.
What even makes such amazing survival skills possible? There are many factorial reasons for this resilience, but one of the most well known capabilities is the ability of certain forms of bacteria to form so called “Endospores”.
Note: I’m thankful to live in the modern day and age when all this information is freely available and composable, thanks to the efforts of countless others who came before me. All relevant links to primary and secondary sources have been posted on the term, and for any that sources I have missed citing, I will work to update this to include those references.
Disclaimer: None of the literature contained in this article is medical advice or to be taken as medical advice. This article is for informational purposes and potentially subject to errors which I’m constantly working to correct. Consult a physician if you have a medical issue.
Endospores
Endospores are shells that bacteria form to protect their DNA from environmental degradation. They are, from a microbiological perspective, “indestructible” or at least exceptionally hearty. Let’s take a look at what this shell is composed of, why it’s so hearty, and what conditions are required to enter and exit the endospore state.
The bacteria essentially, through a process called “sporulation” separates its body into two parts and copies its DNA (the so called bacterial chromosome) into one of those parts. This is essentially the spore part.
Note: This is not the same as a fungal spore, which is something yeast and other fungal entities reproduce by.
So is the bacteria living at this point, when it copies itself? It’s still living but it’s not in its so called vegetative state, which is the state when the bacteria is simply reproducing and metabolizing as normal. It’s more like it’s in a replicative slumber. Some could even say that’s “non-living” in that it can only return back to the land of the living by being awakened by the correct environmental factors.
To enter this state, the non-spore part of the bacteria actually forms a shell around the bacteria, engulfing it. It also dehydrates itself, expelling its water into the extracellular environment, so that its internal metabolism ceases, even though the molecules of metabolic activity remain. This is weird from a macrobiotic perspective, but a perfectly normal phenomenon of the microbiotic world.
For a human, it would be the equivalent of sucking your head down your neck, shrinking your head by extracting all the aqueous contents, and having it live in your abdomen, where it would be protected from outside incursion, by having your stomach form another skull made of steel around it. Once this second skull is formed, then your body would be simply discarded, and you would be a double skulled dormant brain until your enviroment decided your brain should expand again by sucking in water, cracking the steel outer skull, and growing a completely new body from scratch. Like I said: BIZZARE!
After engulfing the spore, the spore starts to form multiple layers of protein around it, embedded with calcium and a molecule called dipicolinic acid, making it progressively tougher and heat resistant and also performing the aforementioned expulsion of water out of the bacterial body. This process goes on for about 7 hours on average, until finally an outermost super-tough layer of keratin surrounds it. Keratin is basically the stuff your fingernails are made of, which aren’t the hardest things in the world from a macrobiotic level, but are much harder than your skin, and on bacterial scales, are one of the most impenetrable structures known. This shell is called the corex
In this shell state the bacterial spore is inactive and can remain that way for up to thousands of years if need be. Supposedly some scientists have discovered bacteria in the spore state from 10s of millions of years ago. After awaking them, “so-called” ancient time capsules are uncovered, giving a snapshot into microbial life from prehistoric times.
Awakening
So how do the endospores “awaken” and go back to living? Earlier I mentioned environmental conditions, and usually to enter the spore state, stressors need to induced on the bacteria cell walls to indicate they are in danger from excessive heat, excessive cold, toxins like human made antibiotics, low food (no sugars are amino acids like Alanine present), . When these stressors are there, a chemical signal cascade causes spore formation activities. The reverse situation needs to be true for the bacteria to return from their spore state to their vegetative state.
When conditions are favorable, the spore will rehydrate, which reignites metabolism pathways like glycolysis. As water enters the spore, the expanding of the spore from inside will eventually cause the external shell to crack and shatter. After this the bacterial DNA can continue to be transcribed and protein production via ribosomal activity can commence — hence, life begins anew. This entire process by the way is called germination, which is akin to when a baby plant germinates from a seedling.
Dangerous Spore Forming Bacteria
While endospores allow bacteria to survive the harshest environments on earth, they are downright deadly for humans in many ways. Endospores not only protect bacteria from natural stressors, they also protect them from antibiotics.
The most commonly cited bacteria cited as being able to form endospores are clostridium and bacillus. Clostridium is probably the more well known of the bacteria, intimitely to most people because it lives in the gut. It’s also a bearer of Clostridium related diseases, and since it’s anaerobic, an oxygen rich enviroment is one of its stressors, causing it to form a spore, until reaches an oxygen free environment in which case germinates and becomes vegetative again.
Clostridium Difficil in fact gets its name from being difficult to kill because of its spore forming nature and can lead to many diseases. I’ll get into another entire article regarding bacterial diseases at somepoint, but I hope this article give you a lot to think about!
