What is the industrial importance of microorganisms?

Microorganisms in food production

Little helpers are often used to ensure that food tastes the way we know it: microorganisms. These are now used as standard for food production. Without the useful microorganisms, the production of yoghurt, bread or cheese, for example, would not be possible at all. Those who know better have researched which microorganisms are used to produce food, what they can do and how they affect the taste of our food. The BESSERwisser also investigated the question of what happens to the microorganisms from food in our body.

The term microorganisms encompasses a very heterogeneous group of microscopic living things. Microorganisms, which are often referred to as microbes or microorganisms, can be divided into single-cell and multicellular organisms. The unicellular microorganisms include bacteria and protozoa - these are unicellular cells that, in contrast to the seedless bacteria, have a real cell nucleus (e.g. paramecia). Fungi and algae, which consist of a few cells, are also microorganisms. Strictly speaking, viruses do not belong to the microorganisms, but they are still often included. What many do not know: Microorganisms make up around 70 percent of all biomass. It is now estimated that our planet is home to around a trillion microbial species [1].

Many microorganisms are fundamental elements of the food chain because they produce important substances. However, microorganisms can also break down organic matter into inorganic substances and thus play an important role in geochemical material cycles. Microorganisms are sometimes cultivated in a targeted manner and are used for a wide variety of applications. For example, bacteria can help with wastewater treatment or with the breakdown of oil films in bodies of water, or they can be used for the production of pharmaceuticals or technically usable substances. And in the production of food it is now standard to use a wide variety of microorganisms.


Yeasts are among the lower fungi and multiply by sprouting or splitting. These unicellular organisms are the most important microorganisms used in food production. Their ability to convert sugar into alcohol during alcoholic fermentation and to ferment food has been used by humans for a long time.

Alcoholic fermentation: Fermentation is the metabolic process in which, under anaerobic conditions - that is, in the absence of oxygen - carbohydrates are broken down to produce energy. During the alcoholic fermentation of the yeast, carbohydrates, especially glucose, are converted into ethanol and carbon dioxide. Yeast grows explosively under the right conditions.

For example, yeast was used to make beer in ancient times - but under less controlled conditions than today. In nature yeasts can be found as so-called wild yeasts, but culture yeasts are bred and used for food production. . The metabolic products formed by yeast allow the dough to rise during baking and help drinks to achieve their alcohol content. That is why yeasts are used, for example, in the production of bread, beer, wine and spirits.


A very heterogeneous genus of filamentous fungi is called mold. Even if spoiled food is often associated with them at first, there are also representatives of this genus that can be used for food production and are mainly used here for fermentation processes. In the production of Roquefort or Camembert For example, noble molds are used as ripening organisms and give the cheese its typical taste without being harmful to humans. Even in the production of salami, alcohol or citric acid molds are used. Flavorings or food colors from mold are also used in the food industry. An example of this is the manufacture of red rice.

Lactic acid bacteria

Lactic acid bacteria belong to a specific group of bacteria that preserve food through the process of lactic acid fermentation. They are widespread in nature and can also be found in the digestive tract of humans. Humans have been making use of the properties of lactic acid bacteria for many thousands of years.

Lactic acid fermentation: During lactic acid fermentation, carbohydrates are broken down into lactic acid and carbon dioxide. The lactic acid gives the food its characteristic sour taste and makes it more durable by preventing the growth of undesirable microorganisms.

The lactic acid produced by the lactic acid bacteria causes milk to thicken and is used in the production of Yogurt, buttermilk, cheese and other dairy products for use. Lactic acid bacteria are also used in the Winemaking, in the production of Sourdough, sauerkraut, as cocoa. Also for probiotic productsLactic acid bacteria are used to support our intestinal flora.

A combination of several different microorganisms is often used in food production. For example vinegar obtained by fermenting wine with yeast and acetic acid bacteria.

It used to be the opinion that humans consist of around 10 times more microbial cells than human cells. The total weight of the microorganisms in and on humans has been estimated at 0.5 to 1 kilogram [2]. This view has since been revised. Today it is assumed that the human body houses around 30 trillion microorganisms on average and consists of about the same number of human cells. According to new calculations, each person carries around 200 grams of microorganisms with them [3].

The microbiota is the totality of all microorganisms that colonize a person, and the microbiome is the totality of all their genes or genomes. Each person has a unique composition of microorganisms that colonize them and leaves their personal “microbiotic fingerprint” in their environment.

Every person has a unique composition of microorganisms that colonize them and leaves their personal “microbiotic fingerprint” in their environment. In connection with humans, microorganisms are often the first to be associated with pathogens. Most microbes in and on people are not pathogenic germs, but rather perform important functions. Microorganisms help, among other things, to use food, break down toxic substances or block surfaces in order to prevent colonization with pathogens.

Microorganisms appear on and in our body in a wide variety of ways: they are absorbed by us through skin contact, through inhalation, but also through food. What patterns the growth of certain populations then follow in the body and what influences it is the subject of intensive research. Since correlations between certain diseases and the composition of microorganisms in the body have been observed, the study of the human microbiome is a very promising field of research. It is still unclear to what extent the active and inactive microorganisms that we ingest through food also have an impact on illness and health. And the question of whether certain diseases can be prevented or even cured through food remains open at the moment.


[1] Locey KJ and Lennon JT: Scaling laws predict global microbial diversity (2016). PNAS. 113: 5970-5975

[2] Luckey, TD: Introduction to intestinal microecology (1972). At the. J. Clin. Nutr. 25, 1292-1294

[3] Sender R. et al .: Revised estimates for the number of human and bacteria cells in the body (20 16). PLoS Biol. Aug 19; 1 4 (8)


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