Microorganisms, the invisible tiny giants, are the powerful allies that sustain life on our planet. When we hear the word “microbes”, it reminds many of us of germs, infections, and diseases. Here comes the real question: are they always harmful to us? 

You might be surprised to learn that only a small fraction (approximately 5%) are pathogenic; the remaining 95% work quietly and tirelessly to maintain nature’s balance.

International Microorganism Day is observed annually on 17 September to commemorate those tiny life forms that have profoundly influenced our world. The history behind this observance dates back to 17 September 1683. On that very day, the Dutch self-taught scientist, Antonie Van Leeuwenhoek, wrote a letter to the Royal Society of London describing the revolutionary discovery of single-celled organisms, which he named “animalcules”. 

Since 2017, the Portuguese Society of Microbiology has established International Microorganism Day (IMD) on 17 September of each year to commemorate it. 

Four mascots, inspired by two bacteria and two fungi —Bak, Saca, Gillus, and Rizzo —represent IMD and were developed to emphasise the additional positive functions that bacteria play in our daily lives. These four mascots reflect the diversity and crucial roles of microbes.

This day aims to bring microbe enthusiasts from around the world together, providing them a platform, both online and offline, to express their knowledge and passion about the microorganisms that shape our everyday lives, for students of all levels.

Microbes are living entities that cannot be seen without a microscope, such as bacteria, fungi, algae, viruses, and protozoa. These creatures inhabit soil, ocean, air, and even live within our very bodies.  Did you know that the human body is home to over 39 trillion microbial cells in addition to roughly 30 trillion human cells? The normal microbiota is a population of beneficial bacteria that dwells inside our bodies. They quietly aid in food digestion, vitamin production, and immune system strengthening. 

Microscopic algae called cyanobacteria carry out an even more remarkable function; they produce a significant portion of the oxygen on Earth.

They have numerous other contributions as well. In the food sector, yeast gives us bread, biscuits, and cakes. Bacteria make it possible for us to enjoy foods like yogurt, cheese, pickles, and soy sauce. Through fermentation, they create wine, vinegar, and other beverages. 

They also have a lot to do with medicine: microbial power creates vaccines, countless drugs, and antibiotics like penicillin that can save lives. Even the environment benefits from bioremediation, which uses bacteria to clean up oil spills and lower pollutants. 

In agriculture, nitrogen-fixing bacteria enhance soil fertility and boost crop yields, while defence microorganisms in our own bodies protect us from harmful invaders.

The tale isn’t all positive, of course. Certain microorganisms are lethal. They are responsible for illnesses like influenza, TB, cholera, dengue, and malaria. They have also been responsible for catastrophic pandemics and food spoilage. 

You must have heard people saying in our country, “Oh, I have a runny nose. I’ll take an antibiotic, I’ll be okay tomorrow morning,” and then pop a capsule just like that. Yet we never stop to wonder how harmful this small act can be. Antibiotics only combat bacteria; not all antibiotics work against the same bacteria. We should take antibiotics only when a physician prescribes. 

It’s a matter of great concern that antibiotic abuse and overuse over the years have led to the evolution of bacteria. The uncontrolled use of antibiotics made bacteria smarter. Now they do not respond to certain common antibiotics, which we call antibiotic resistance. The scariest part is that more exposure to antibiotics has led certain bacteria to become “superbugs” that are highly resistant to treatment.

As a microbiologist, I believe it is my duty to tell people that microbes can be allies or enemies. Solutions come from knowledge. By educating ourselves and remaining informed, we may also contribute to the prevention of antibiotic resistance.

Imagine germs combating cancer cells without endangering the rest of our body, or bacteria that are modified to degrade plastics, garbage, and purify our oceans. Researchers are even designing bacteria that can produce oxygen for astronauts to thrive on Mars, biofertilizers instead of chemical fertilizers, and create environmentally friendly biofuels. 

International Microorganism Day raises awareness of issues beyond science. It serves as a reminder that, despite their potential for harm, we should be excited because microbes have the potential to be our best allies in resolving humanity’s most pressing problems in the near future. These unseen living beings are truly deserving of our admiration and interest.