In botanical language, the term "saprophyte" (from the Greek sapros, rotten and phyton, plant) is now obsolete and outdated, although some scientific texts still carry this word to indicate all those microorganisms that, to live, need the nourishment of matter decaying organic matter .
Most lichens are considered saprophytes (organisms composed of cyanobacteria and fungi); some bacteria and some protozoan forms are also included in the saprophytic category.
All saprophytes are heterotrophic organisms, therefore unable to produce their own nourishment from inorganic material .
Being excellent decomposers, some saprophytes represent a precious element of ecosystem food chains; these heterotrophic organisms, by simplifying the complex organic substances in elementary inorganic matter (eg mineral salts, water, etc.) are indicated for the formation of humus. In other words, with their action, the saprophytes (or saprogens) favor the decomposition of lifeless organic substances, contributing, in this way, to humification (set of demolitive processes of an enzymatic nature in which the organic matter is subject to reworking).
Saprophytic bacteria should not always be considered carriers of damage; just think, for example, of those who live in symbiosis with the intestinal bacterial flora of man: thanks to their presence, the integrity of the intestine and defense against diseases is guaranteed, thanks to the synthesis of vitamins and trace elements which are very important for the well-being of the intestine. Furthermore, the presence of these saprophytes in the intestinal tract (within a certain range) prevents any pathogenic bacteria, viruses and fungi from causing you damage.
Note : an excessive concentration of saprophytes in the intestine can trigger the opposite effect and create damage like normal pathogens. For example, Candida albicans is a saprophyte of the digestive tract and oral cavity, so in physiological conditions the fungus normally lives in these sites, without causing damage. In addition to the digestive system and the buccal cavity, Candida albicans is a component of the vaginal bacterial flora in 10-20% of women (asymptomatic form). However, when there is an alteration of the local bacterial balance, therefore in conditions favorable to mycetes, the saprophyte proliferates in an exaggerated way, creating the common infection that dresses of the same name (oral and vaginal candidiasis).
Together with some bacteria, mushrooms are very important recyclers of carbon, nitrogen and essential trace elements: this recycling process is very useful, since it favors the simplification of complex materials - such as cellulose and lignin - in simple molecules, usable also by fungi and others microorganisms.
In the past, fungi and bacteria were also included in the saprophytic group; currently, however, these two categories have been excluded from the vegetable kingdom, so neither fungi nor bacteria can be properly defined as saprophytes.
