En DE ES

Glossary

Microorganisms

Microorganisms are microscopically small organisms that cannot be seen by the unaided human eye. They are also called microbes or micro-animals. Microorganisms do not form a uniform bio-systematic group. Most of them are single-celled organisms, often colonial organisms of the same size, such as fungi and algae. Microorganisms hold a special position in the animal and plant kingdom because they are so tiny. Their scientific study is the subject matter of microbiology. Microorganisms include bacteria (e.g. lactic acid bacteria), various fungi (e.g. baker’s yeast), microalgae (e.g. chlorella) and protozoa (e.g. paramecium and the malaria pathogen plasmodium). Whether the group microorganisms should also include viruses is disputed. Although viruses are mostly not considered to be living organisms, they are sometimes classified as microorganisms. In this case, viral research (virology) is also a branch of microbiology. Microorganisms take on important functions in the general material metabolism. As producers, they form the basis of many food chains (e.g. pebble algae), and, in their function as decomposers, they also degrade organic matter into inorganic substances. Some microorganisms are important for food processes, others for desired metabolic substance transformations, and others are parasites and pathogens of infectious diseases. There are far more microorganisms than other living beings. Their percentage of the total terrestrial living biomass is 70 percent.