Field of Science

Earth Day 2011

Okay so I missed it in my timezone but like beer o'clock it’s always the right time somewhere. Earth Day is an important opportunity to look at the way we use the environment and consider ways we alter our impact for the better.

Below is an article that I previously published in the Adelaide Advertiser, the main newspaper from where I live about a much overlooked but vitally important cog in the environment, bacteria. It’s about a year old and I have mentioned it before but some of the info is worth another look.

Happy Earth Day, for yesterday.
Earth view from Orbiter (modified from)

BACTERIA are often victimised and not without good reason. They can make us sick and rot our food, but not all bacteria are bad. Without them, our world would simply cease to function as we know it.

Earth is sometimes referred to as the planet of the microbes because the number of microbes on this planet is simply staggering. We can assume there are roughly seven billion people around the world. Our best estimate on bacterial numbers alone is five million trillion trillion.

This means that for every person on Earth, there are about seven million billion bacteria. To write this number, you would have to start with a seven then put 20 zeros after it.

Even with so many bacteria, viruses still outnumber bacteria 10 to 1. These numbers are simply incomprehensible.

It amounts to one simple fact: Wherever we look for microbes, we will find them.

Bacteria do not simply just exist for the sake of it. More often than not, we find them performing some vital role that keeps our planet ticking over.

For a long time, we have known about bacteria that are capable of surviving the crushing pressures, lack of oxygen and soaring temperatures found within deep-sea vents. These bacteria, called thermophiles (or in some cases extremophiles) not only live, but thrive in these conditions that were considered for a long time by many to be too hostile for any organism. These bacteria also play a very significant role. They are able to absorb toxic compounds produced by other organisms, such as hydrogen, metabolic by-products and other unusual biological compounds, and recycle the base elements back into the food chain allowing a constant food supply to ‘‘trickle up’’ to higher organisms.

But it’s not just the bottom of the sea we find bacteria living out on the edge. The craters of active volcanoes are also teeming with microbial life.
Bacteria mats near the Grand Prismatic Spring in Yellowstone National Park
If you are so inclined, you can even find bacteria when looking in clouds.

Recent research indicates that not only are they up there but we might need them to be. Bacteria can bring the rain.

It seems that some bacteria, particularly some environmental strains like Pseudomonas syringae, have adapted their lifecycles to include ‘‘rain transmission’’. The bacteria are swept up into the atmosphere by wind but once in the air can act as ‘‘nucleation points’’ for condensation and ice crystal formation.

These events can trigger chain reactions resulting in the formation of clouds and eventually rain and snow. It’s important to remember that bacteria do this for a reason. In the case of P. syringae, it is primarily a plant pathogen that enters and leaves plants via leaf structures called stomata.

By adapting to and evolving a method of spread through the rain, the bacteria can greatly increase their own spread throughout the environment. As well as trawling the ocean floor and bringing the rain, bacteria have been implicated in everything from rock formation to preserving water quality and, of course, they play a major role in our ability to stay healthy.

The tools bacteria use to fight each other provide us with options for antibiotics and disinfectants and even by just occupying space on your skin, up your nose and in your gut, they help to try to prevent the bad bacteria being able to get a foothold and make you sick.

So the next time you see something disgusting and immediately blame it on the ‘‘germs’’, just remember that without them we wouldn’t be around to be disgusted.

1 comment:

  1. Nice story, I really liked the way you described those INSANE numbers in a way that makes them comprehensible (if only in their incomprehensibility - I appreciated that those were BIG numbers) Bacteria in clouds, hey? I didn't know that, how cool.


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