Saprotrophic nutrition
File:Hyphae.JPG|thumb|right|Mycelial cord of fungi made up of a collection of hyphae; an essential part in the process of saprotrophic nutrition, it is used for the intake of organic matter through its cell wall. The network of hyphae is fundamental to fungal nutrition.
Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed organic matter. It occurs in saprotrophs, and is most often associated with fungi and with soil bacteria. Saprotrophic microscopic fungi are sometimes called saprobes. Saprotrophic plants or bacterial flora are called saprophytes, although it is now believed that all plants previously thought to be saprotrophic are in fact parasites of microscopic fungi or of other plants. In fungi, the saprotrophic process is most often facilitated through the active transport of such materials through endocytosis within the internal mycelium and its constituent hyphae.
Various word roots relating to decayed matter, to eating and nutrition, and to plants or life forms produce various terms, such as detritivore, detritophage, saprotroph, saprophyte, saprophage, and saprobe; their meanings overlap, although technical distinctions narrow the senses. For example, biologists can make usage distinctions based on macroscopic swallowing of detritus versus microscopic lysis of detritus.
Process
As matter decomposes within a medium in which a saprotroph is residing, the saprotroph breaks such matter down into its composites.- Proteins are broken down into their amino acid composites through the breaking of peptide bonds by proteases.
- Lipids are broken down into fatty acids and glycerol by lipases.
- Starch is broken down into pieces of simple disaccharides by amylases.
- Cellulose, a major portion of plant cells, and therefore a major constituent of decaying matter is broken down into glucose
Conditions
In order for a saprotrophic organism to facilitate optimal growth and repair, favourable conditions and nutrients must be present. Optimal conditions refers to several conditions which optimise the growth of saprotrophic organisms, such as;- Presence of water: 80–90% of the mass of the fungi is water, and the fungi require excess water for absorption due to the evaporation of internally retained water.
- Presence of oxygen: Very few saprotrophic organisms can endure anaerobic conditions as evidenced by their growth above media such as water or soil.
- Neutral-acidic pH: The condition of neutral or mildly acidic conditions under pH 7 are required.
- Low-medium temperature: The majority of saprotrophic organisms require temperatures between, with optimum growth occurring at.