In botanical language, the term "saprophyte" (from the Greek sapros, rotten and phyton, plant) is now obsolete and outdated, although some scientific texts still report this word to indicate all those microorganisms which, in order to live, need the nourishment of decaying organic matter.
Most lichens are considered saprophytic (organisms composed of cyanobacteria and fungi); some bacteria and some protozoan forms are also included in the category of saprophytes.
All saprophytes are organisms heterotrophs, so unable to produce their own nourishment from inorganic material.
Being excellent decomposers, some saprophytes represent a precious element of the food chains of ecosystems; these heterotrophic organisms, simplifying complex organic substances into elemental inorganic matter (eg mineral salts, water, etc.) are indicated for the formation of humus. In other words, with their action, saprophytes (or saprogens) favor the decomposition of lifeless organic substances, thus contributing to humification (a set of enzymatic demolition processes in which organic matter is subject to reprocessing).
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 the defense against diseases are 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 harm.
Please note: an excessive concentration of saprophytes in the intestine can trigger the opposite effect and create damage like normal pathogens. For example, the Candida albicans it is a saprophyte of the digestive tract and oral cavity, therefore in physiological conditions the fungus normally lives in these sites, without causing damage. In addition to the digestive system and the buccal cavity, the Candida albicans it 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 the fungi, the saprophyte proliferates in an exaggerated way, creating the common infection that takes the same name (oral and vaginal candidiasis).
Together with some bacteria, fungi 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 - into simple molecules, which can also be used by fungi and others. microorganisms.
In the past, fungi and bacteria were also included in the saprophyte group; currently, however, these two categories have been excluded from the plant kingdom, therefore neither fungi nor bacteria can be defined properly saprophytes.
