Bacteria, the great improviser
As the cliché goes — one man’s garbage is another man’s treasure.
And also, perhaps, a viable buffet of tasty, tantalizing delights.
Bacteria are notorious for eating our waste. They attack, devour, proliferate and thrive in all kinds of unseemly matter. They colonize rotting food and break down the organic matter into usable material for their biological functions. Within our own intestines they happily congregate within the cozy folds, breaking down the last remnants of food and synthesizing Vitamin K — which helps prevent us from bleeding to death. Thanks, bacteria.
They happily monopolize our fecal matter as it journeys through us and out into the great unknown.
We need bacteria. In a world without bacteria dead things would linger indefinitely. Dead leaves and vegetation would pile up on top of each other, wildly taking over every square inch of land. And so would we after our death — or, to be more specific, the void shell that was once us would linger.
One way of reaching immortality, I suppose. In a world without bacteria our empty bodies would essentially exist forever.
It would appear that our planet would be in some trouble without our bacteria buddies.
And yet, despite all of bacteria’s ravenous ways, we are still in a predicament. Plastic is set to overrun us and reign supreme. A true immortal, plastic may out last all of us — piling up increasingly, choking the life out our oceans and littering our lovely beaches.
In response, we halfheartedly try to limit our plastic consumption. But honestly, scrapping your drinking straws is really a last-ditch effort here. One that is not likely to save us, despite all our good intentions.
The Great Plastic Feast
Enter Ideonella Sakaiensis, an unassuming rod-shaped bacteria that was discovered, only a hand full of years ago, feasting on plastic outside a bottle recycling facility.
Up until then, it was assumed that biodegradation — or the breaking down of material through biochemical means — was not a viable option for dealing with our plastic problem.
However, it appears this bacterium had found a way to utilize all of this plastic potential. To quote my childhood crush, Dr. Ian Malcolm —Jeff Goldblum’s character in Jurassic Park — “Life, uh, finds away.”
Little Ideonella uses a couple different enzymes to break down polyethylene terephthalate or PET. PET is catabolized (fancy biochemistry word for” breaking down big things into smaller pieces”) into two molecules—terephthalic acid and ethylene glycol— which the bacteria then use as a major energy source.
Recently, it appears scientist have been able to harness the power of Ideonella’s enzymes and even improve on their potency.
Meaning, the ability to break down plastic may potentially be at our finger tips. Potentially.
Plastic eating bacteria are a product of evolution. Bacteria are brilliant and resilient — able to reinvent themselves in the harshest of environments. When the going gets tough the bacteria get going (Groan). In the presence of antibiotics, the strongest bacteria pass on the keys of survival to select others in their colony. This “resistance” gene or plasmid is a passed on again and again through a process called horizontal gene transfer. The end result is the very familiar, yet still terrifying, antibiotic resistance.
Bad news for us.
Much of this resistance arises from the bacteria’s ability to change how it utilizes resources or alter various faculties it already processes. From using heavy metal pumps to pump out the antibiotics to manufacturing an enzyme that attacks its very attacker — bacteria can MacGyver their way out of many a situation.
So, when bacteria show up outside of a recycling facility, you know they have adapted to and have utilized their environment to their advantage.
They are not the first organism to alter themselves in the face of adversity.
Dark Moth Rising
The peppered moth pulled a similar trick over a hundred years ago.
Before the nineteenth century, the peppered moth was a delicate little white creature with black speckles that were —uhh—”peppered” across it’s wings. This allowed them to camouflage on lichen covered trees. A safety feature that helped to protect them from being picked off by their natural predators
Now, in nature you have a few naturally occurring mutations. The white, or light coloured, peppered moth is something called a “wild type phenotype” meaning it is the most abundant version of its kind to be found among the lichen covered bark. One mutation, however, gives rise to a very dark peppered moth.
This dark moth exists in far fewer numbers because:
a) it’s a mutant
b) the dark wings make the moth stand out — signaling to predators that lunch is served.
But, this moth’s dark wings proved to be an advantage over our wild white friend centuries ago
With the rise of the Industrial Revolution in Europe, smoke and soot from coal fires filled the air and settled on the streets. This thick black dust coated buildings and trees, killing off the lichen and painting the bark a shade too dark for the lightly speckled wild type moth. Soon the delicate little white moth was dying at a rapid rate— their white wings, now in stark contrast against the new dingy backdrop, made them vulnerable.
The darker moth, on the other hand, thrived. It’s population soon surpassed the lighter moth, usurping the throne to become the dominate phenotype.
The darker moth was able to pass on it’s version of genes in more numbers than ever before, allowing these black sheep of the bug world to proliferate and happily exist among the soot and the smoke-filled air of progress.
The story of the peppered moth is a specific type of natural selection called directional selection — where an extreme phenotype, or physical appearance, is favoured over another. This leads to a shift in the population.
Once the coal fires died down and industrialization’s pollutants were brought under control by legislation, the tables once again turned on the dark moth — leading to a ebb in population and the restoration of the white winged moth to their rightful wild type throne.
The resilience of the natural world is incredible and, occasionally, unsettling. Nature manages to alter itself in the harshest of circumstances and sometimes, even thrive in these less than ideal situations. This has implications and impact on us. It can be detrimental (antibiotic resistance), beneficial (plastic eating enzymes) or neutral (different flavours of moths) to us lowly humans.
Life, uh, really does find a way, doesn’t it?
Moths and Microbes