As Christmas approaches, the weather around here changes dramatically. I have to give myself an extra 10 minutes in the morning just so I can scrape my car windshield and possibly traverse through adverse winter conditions. As I step outside into the bitter cold every morning, I wonder how long I could actually survive in these conditions… Thirty minutes? One hour? Perhaps only fifteen minutes because as I enter my car I am convinced my fingers are about to fall off! All organisms have to learn to adapt in order to survive extremes in weather. For humans, we have evolved a large brain and have developed skills necessary to build structures to help us survive temperature extremes. Other organisms aren’t as fortunate as we are and have to live in the extreme temperatures and have to adapt in far more dangerous conditions. However, various living things around the globe have developed incredible adaptations to survive in harsh climates and under ruthless circumstances.
Common adaptations we have all heard about include hibernation, thick fur or blubber to keep the warmth inside the body, and even avoiding the cold all together by flying south to a more suitable climate. Other animals will simply “roll with the punches” and become frozen all winter and then thaw out and carry on with their lives as normal once spring hits (various insects and frogs employ this tactic). Still others have more unique tactics like evolving blood similar to antifreeze. Animals like the Antarctic icefish have chemicals in their blood that prevent ice crystals from forming inside of them, which would quickly prove to be detrimental to their circulation system and fatal to the organisms overall. But, in my opinion, certain strains of bacteria have one the “greatest evolutionary method of survival in adverse conditions” award (it cost me like an extra ten bucks to fit that title on a plaque).
Certain strains of bacteria form endospores to help them survive literally any and all adverse condition ever thought of. To paint a picture of what an endospore can do for bacteria, picture a gaint meteor the size of Mercury crashing into our planet along with worldwide nuclear fallout combined with a runaway greenhouse effect causing global temperatures to exceed 200 degrees Fahrenheit all wrapped in a bow of zombie apocalypse! Yep, an endospore could solve all of those problems! (Minor side note: scientists have not tested the strength of endospores in the conditions listed above, though I have heard zombie apocalypse testing is well underway)
Word of the Week: “Endospore”–A dormant and highly resistant cell to preserve the cell’s genetic material in times of extreme stress.
Certain strains of bacteria that have the capability of forming endospores, like Bacillus subtilis, do not carry around the endospores their entire lives. This would be disadvantageous for the reproduction of the bacteria. You see, once the bacterium is enclosed in an endospore, it can neither feed nor reproduce but is in a dormant state until more suitable living conditions become available. The development of an endospore is triggered in response to the lack of nutrients in its environment. Once the endospore forms inside of the bacterial cell (a cell formed within a cell) the mother bacterial cell dies and the endospore is released into the environment encasing the DNA of that mother bacterial cell. The endospore will remain dormant until more favorable living conditions return.
So what makes an endospore so effective? It is basically like carrying around your own personal bomb shelter with PLENTY of protective layers. The bacteria’s “bomb shelter” is made of an outer coating that provides much of the chemical and enzymatic resistance necessary for survival along with a very thick layer underneath that called the cortex which protects it from temperature extremes. But let’s not forget about the germ cell wall underneath that which gives added protection and will eventually become the bacterial functioning cell wall once living conditions become available again. Oh and how could I forget about the inner membrane underneath the germ cell wall which is an added barrier to guard against other specific damaging chemicals. Finally we have the core of the endospore which contains various survival tools such as dipicolinic acid, which helps maintain the spore’s dormancy, and small acid-soluble proteins (or SASPs for short) which tightly bind and condense the DNA and are responsible for UV and other DNA-damaging chemical resistance.
In case I lost you in that last paragraph of awesomeness, the endospore is one of the most effective adaptations on this planet for surviving in harsh environmental conditions. If one organism were to survive the biggest natural disaster this planet has ever seen, my money is on bacteria. They have been alive far longer than any other living thing on this planet and have evolved some decent survival skills to say the least. Let’s just say, “this isn’t their first rodeo.”
There are also strains of bacteria inside of surgeonfish that produce and use endospores nightly. These bacteria are beneficial to surgeonfish, they aid in the digestion of food. But at night, when the fish eat far less, the bacteria is preserved overnight until more food is digested by the fish in the morning and ready for the bacteria to break down. The endospore, having fulfilled its mission in preserving the cell, then gives way to the living bacterium.
We, as humans, are intelligent beings who have no need of some of these adaptations. However, I believe we would be foolish not to acknowledge and learn from the artful adaptations of other organisms around us. Who knows, the adaptations of mere bacteria may even shed light on a better way of living for us humans. It sure would not be the first time that has happened and it won’t be the last.
If you read this whole blog post, you are my hero! Thanks for reading. Please feel free to leave me a comment and feedback below. Also, let me know if there is any particular science topic you would like me to look at “through green tinted glasses” and I will write about it. The topic for this post came from a subscriber’s suggestion. Keep them coming!
*Most of the information from my writing in this blog came from the College of Agriculture and Life Sciences at Cornell University in the following website: https://micro.cornell.edu/research/epulopiscium/bacterial-endospores/