Microorganisms

In the world of medical science and technology and healthcare there is a continual reference to microorganisms or microbes.

What are microbes?

Microorganisms or microbes are very diverse; they include bacteria, fungi, microscopic plants (green algae) and animals such as plankton. Some microbiologists also include viruses, but others consider these as non-living.  Most microbes are single-celled, but some are multicellular organisms, while some unicellular bacteria are macroscopic and visible to the naked eye.

The Importance of Microbes

Microbes live in all parts of the biosphere where there is liquid water, including soil, hot springs, on the ocean floor, high in the atmosphere and deep inside rocks within the Earth's crust. They are found in all living things, plants and animals. There are more microbes on and inside your body than there are cells that make up your entire body.   As some microbes can fix nitrogen, they are a vital part of the nitrogen cycle, and airborne microbes may play a role in precipitation and the weather. Microbes also are responsible for building fertile soil for plants to grow in. As decomposers, they are critical to nutrient recycling in ecosystems.   The microbes stick to the roots of plants and decompose dead organic matter into food for the plant to absorb. Human and animal waste products are also broken down into safer particles by some microbes.

Microbes can form an endosymbiotic relationship with other, larger organisms. For example, the bacteria that live within the human digestive system contribute to gut immunity, synthesise vitamins such as folic acid and biotin, and ferment complex indigestible carbohydrates. Microbes are also exploited by people in biotechnology, both in traditional food and beverage preparation, and in modern technologies based on genetic engineering. Drug companies that make medicines use hundreds of different microorganisms to make medicines that will help cure diseases.

Pathogenic microbes and how they are transmitted