Microorganisms: Friends or foe? Welcome to the smaller side of life

You cannot feel them, hear them nor see them with the naked eye, yet they are on every inch of your body. They influence every aspect of everyday life, yet you do not take much notice of them. Some of them can make you very ill whilst some of them are responsible for the brilliant discoveries that we had and continue to have. What is this fascinating ‘creature’ you may ask? Well, the answer that you’ve been looking for are microorganisms! Welcome to the smaller side of life: Microbiology.

Saying hello to tiny organisms that rule everyday life

Organisms that are too small to be seen with the naked eye are termed microorganisms. The study of these microorganisms in return is called microbiology. Microbiology takes into account the study of the different types of microbes, their interactions, structure, genetic diversity and roles in infectious diseases amongst other factors. These organisms are ubiquitous in nature and inhabit almost every space we occupy, from the surfaces that we touch to the air that we breathe in, to the foods and beverages that we consume. Microbiology, at large, encompasses a wide range of disciplines which consist of many exciting fields such as mycology, parasitology, bacteriology, and the likes.

Microorganisms: A class of their own

Ever consumed a refreshing glass of wine or beer after a long, hard day at work? Did you know that you are essentially consuming yeast, which is one of the many groups of microorganisms?

There are 5 main classes or groups that microorganisms fall under:

1. Bacteria

You decide to reheat some leftover food that has been in the fridge for a few days now. However, you get caught up with work and some time passes by before you decide to have that delicious bowl of reheated soup. A few hours later and you are in agony! You feel sick to your stomach. That sounds like a nasty bout of food poisoning. Ever wondered what causes food poisoning? Bacteria, of course!

These unicellular organisms do not consist of a nucleus (also known as prokaryotic) and are found in various shapes: bacillus (rod shaped), vibrio (curved shape) and coccus (spirillum shaped). The fundamental feature that scientists use to distinguish different bacteria is a change in the composition of bacteria's cell walls. Bacteria that can grow in the presence of oxygen are known as aerobic bacteria, bacteria that can thrive in oxygen-deficient settings are known as anaerobic bacteria, and bacteria that can grow both with and without oxygen are known as facultative anaerobes. Can humans live in environments with low oxygen levels? Certainly not. However, bacteria, a resilient group of organisms, are fascinating microorganisms - when they aren’t wreaking havoc and making humans sick!

2. Fungi

At some point or the other, you may have consumed mushrooms. They may even be in your list of favourite foods. But did you know that mushrooms are a type of fungi?

Fungi are organisms that are made up of more than one cell (known as multicellular). Fungi exists in two forms: moulds and yeast. They have a true nucleus, meaning their cell's DNA is surrounded by a membrane, which is also known as eukaryotic. They are responsible for symbiotic interactions with other species which can result in harmful relationships with hosts.

3. Protozoa

Protozoa are eukaryotic organisms that are free living and found in almost every environment. A few can be seen with the naked eye but the majority of them are microscopic.

4. Viruses

I am sure at this point you know a thing or two about viruses, considering the pandemic that we’ve been facing since 2019, i.e. Covid-19. Viruses do not consist of cells and are therefore acellular entities. Instead they are either made up of RNA or DNA (genetic information). Viruses need a host to reproduce and cause diseases.

5. Algae

Ever been to the beach and found blue - green plant-like material on the surfaces of rocks? That would indeed be algae! Algae are eukaryotes that are found in moist environments and are believed to be the origins of green land plants.

Now that we know a bit more about the different groups of microbes along with a few characteristics each group entails, let us now explore how microbiology is used in the 21st century.

The advancement of microbiology: changing lives one microbe at a time

The 20th century saw the rapid advancement of microbiology in various sectors, namely agriculture and in medicine. It is thus said to be a particularly exciting time for microbiology. Pharmaceuticals and other related industries are heavily dependent on microorganisms to produce antibiotics, enzymes and chemicals that improve our standard of living and, ultimately, save lives.

The advancement of the food microbiology sector has also tremendously enhanced the safety of the foods that we buy and consume. In the agricultural sector, microorganisms, and their related microbial products, are being used for probiotic therapies and to produce various antibiotics.

Microorganisms also play a crucial role for the environment. Did you know that microorganisms are responsible for the substantial influx of mineral nutrients and organic matter in water bodies? For instance, before releasing sewage into natural waterways, it is of vital importance to treat sewage and wastewaters. The process of cleaning up pollution in the water and other environments is called ‘bioremediation’.

Without bioremediation toxic compounds and organic matter will collect to such a level that there will be massive microbial growth and oxygen consumption. This ripple effect will then cause animals and plants to die off, along with reducing the recreational value of the water. Therefore, to avoid such events, complex microbial communities are exploited and stimulated by treatment facilities, to facilitate the process of removing the high nutrient load of wastewaters. This is done to guarantee that as many harmful nutrients and organic carbon as feasible are removed from wastewaters. When this procedure is finished, the water can be safely discharged into other water bodies.

The future for microbiology

We are living in exciting times as the future for microbiology is promising. The advancements in biotechnology, studies on infectious diseases, and microbial ecology, to name a few, holds promise to improve the quality of our life and the environment that we inhabit. In the past, scientists have only been able to observe mixed microbial species in a single drop of pond water. Now, scientists are able to isolate and study individual bacterial species in a sample of seawater. How fantastic is that? Microbiology has a come long way and has an even longer way to go.

So, the next time you feel alone, bare a thought in mind that you are, in fact, surrounded by a vast number of microorganisms consisting of different shapes, sizes and characteristics. Microorganisms will ALWAYS be there for you if they’re not trying to make you ill, of course! Microorganisms: Friends or foe? You decide.

For more interesting articles about microbiology, plant breeding and plant tissue culture, check out our other blogs!

By Melissa Naidu | 22-March-2022

About the author

Bacteria, fungi, petri-plates and the likes. Those are just a few words that brings joy to any scientist, right? Melissa Naidoo is a qualified Biotechnologist with a focus area in the microbiology sector. She is based in the sunny city of Durban, South Africa. She is currently a microbiology content creator for Lab Associates B.V in the Netherlands and an academic in the private higher education sector in SA.