The tiny world of microbes- they might be small but they are mighty!
Micro-organisms, also frequently known as microbes, are organisms too small to be seen by the naked eye. Many are ancient, developing on the planet well before plant or animal life. These days microbiologists study them and have found there may be as many as a billion different kinds, and they’re discovering more all the time. While there’s huge diversity, microbes can be categorised into five major types that will probably be familiar to you. These are Viruses, Bacteria, Archaea, Fungi, and Protists.
Let’s take a quick look at these:
Bacteria - Bacteria are single celled organisms but beyond this they vary wildly in their functions and preferences. They perform all kinds of functions, from digestion, to rotting down natural materials to fermenting the foods we love, like yoghurt and cheese, A small (less than 1%) number, like Salmonella and Staphylococcus, can cause illnesses.
Viruses - Viruses have no cells, unlike bacteria, instead they consist of a protein shell containing one or more molecules holding genetic information. They aren’t technically classed as living creatures and since their only goal is reproduction they require healthy host cells to replicate this genetic information inside. This replication can cause sickness, from minor colds through to AIDS and of course, COVID-19. Viruses are much harder to treat in general but for several serious diseases we have developed vaccines to boost our immune systems in the fight against them.
Fungi - Fungi are neither plants nor animals and are arguably the most important microbes on the planet. There are hundreds of thousands of types from subterranean networks that span kilometres and help trees communicate, to edible mushrooms, to moulds and yeasts. Like bacteria, they can occur naturally on or in the body in healthy ways, but can also contribute to illness.
Archaea - This group of microbes is similar to bacteria, but are evolutionarily different. Archaea are more stable which means they can survive in more extreme environments. Most extremophiles are Archaea, such as the microbes found living in hot springs and geysers. In fact, these microbes usually kind of mind their own business. They very rarely cause illness. Microbiologists are still pretty confused by them in general and have had to work hard to figure out what the ones found in people really do.
Protists - Protists are diverse and include organisms that are animal-like, plant-like and fungus-like. They are considered the common ancestral link between the evolved versions of these things. Most of them reside in wet or damp environments. They are fairly sophisticated with a highly organised structure and some of them even have primitive locomotory organs to help move them around.
Because of how old they are, all other life has grown and evolved alongside microbes and they are a vital part of existence. They vastly outnumber all other life on earth. However, people tend to associate microbes with negatives. You can see above that they are at the root of sickness. What people don’t often consider is their beneficial roles in our lives. Microbes help all of our ecosystems to function. They exist everywhere from the soil to the clouds to volcanoes. The human body, particularly the skin, mouth and intestines, contains millions of microbes that help us to function and keep us healthy - This is called the microbiome, an invisible ecosystem inside all living things. Your microbiome contains beneficial microbes that help you digest food, process things, absorb and create nutrients, help out-compete invading pathogens and keep you from succumbing to illness.
Outside of our bodies, microbes contribute to everything. Without them, the rest of life wouldn’t exist. They both create and destroy, being the force behind all decay as well as participating in the creation and survival of everything else. They might be small, but they are mighty.
