In times of crisis, bacteria possess a few survival strategies up their sleeves. For instance, certain bacteria resort to consuming their own kind to endure harsh conditions, such as a scarcity of nutrients. This cannibalistic behavior proves to be an effective tactic, leading scientists to hypothesize that bacteria can remain dormant in this manner for millions of years!
Imagine finding yourself on a deserted island after a plane crash, similar to the situation in the TV show LOST, with no food in sight. Would you consider consuming your fellow passengers to stay alive?
Interestingly, bacteria would. In fact, they would even devour their own relatives, as revealed in a study published in the Proceedings of the National Academy of Sciences.
Bacteria Can Survive Without Food for a Thousand Days
In this study, bacteria were collected from the soil and cultivated in a flask with saline solution for 1,000 days. They were deprived of all food sources, yet they were discovered to still be alive even after more than 2.5 years!
So how is this possible? After all, every living organism requires food to survive. As it turns out, bacteria are not sentimental and will consume the remains of their deceased comrades and family members to ensure their own survival.
They do what they must to stay alive. I’m not suggesting that bacteria betray their loyalties and devour their fellow mates while still alive. The stronger bacteria simply consume the remains of the weaker ones that died from starvation—an opportunistic version of ‘survival of the fittest’.
It remains unknown whether the stronger bacteria actively killed the weaker ones. Perhaps bacterial murders are a phenomenon that has yet to be discovered? What we do know is that bacteria possess the means to commit murder, such as enzymes that can create holes in bacterial cell walls. When bacteria employ these murderous tools to eliminate other bacteria, it is referred to as allolysis.
There are also certain bacteria, like Bdellovibrio bacteriovorus, that are capable of consuming other bacteria while they are still alive, but that is a story for another time.
So… did bacteria solely rely on the remains of dead bacteria to survive? Would these remnants be enough to sustain the hungry bacteria for years, decades, or even centuries?
Bacteria Possess Energy-preserving Mechanisms
When we fall ill or come home exhausted after a long day at work, we often feel lazy and lack energy. We don’t feel motivated to do anything except curl up in bed.
Well, bacteria experience something similar. They become so famished and depleted of energy that they halt or slow down their other biological processes. It is akin to feeling lethargic, much like how a bear hibernates during winter. This way, their energy requirements decrease, allowing them to conserve whatever little energy they have left.
The most difficult choices demand the strongest wills.
Bacillus, a bacterial species involved in the study, was found to possess the longest lifespan. These bacteria have the ability to transform into endospores, which is a common survival mechanism utilized by Bacillus species during extended periods of stress. This unique capability is the reason behind their remarkable longevity.
Spores are tiny single-celled organisms that carry the genetic information of their species and can later develop into new individuals. The bacteria called Bacillus creates copies of their DNA and encases them in protective proteins, forming spores that can wait until the conditions are favorable for survival. If food sources enter the environment where the bacteria are growing, these spores will break open and new bacterial cells will grow. However, not all bacteria have this ability to form spores, and those that do require energy, which they obtain by consuming dead bacterial remains.
The study on bacterial survival without food was conducted for 1,000 days, but based on mathematical analysis, it is estimated that these bacteria could survive for approximately 100,000 years without food. However, it would be challenging to scientifically prove this, as the lead scientists would not live long enough to confirm the hypothesis.
Apart from starvation, bacteria have shown the ability to survive in extreme environments such as deserts and ice-covered continents. Scientists have even revived bacteria from the ocean that had been dormant for over 100 million years. These resilient bacteria can survive in environments with little to no energy supply, which raises questions about how they manage to do so.
Understanding the dynamics of bacterial survival is crucial for understanding the history of life on Earth and could provide insights into the origins of life. It could also lead to the development of new strategies to target antibiotic-resistant bacteria and treat aggressive diseases. In conclusion, bacteria can resort to cannibalism when they starve, but they consume the remains of the dead rather than craving the flesh of the living.