Saprotrophic nutrition /sæprɵˈtrɒfɪk/ is a process of chemoheterotrophic extracellular digestion involved in the processing of dead or decayed organic matter. It occurs in saprotrophs or heterotrophs, and is most often associated with fungi (for example Mucor and Rhizobium) and soil bacteria. Saprotrophic microscopic fungi are sometimes called saprobes; saprotrophic plants or bacterial flora are called saprophytes (sapro- + -phyte, "rotten material" + "plant"). The 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 (detritus, sapro-), eating and nutrition (-vore, -phage), and plants or life forms (-phyte, -obe) produce various terms, such as detritivore, detritophage, saprotroph, saprophyte, saprophage, and saprobe; their meanings overlap, although technical distinctions (based on physiologic mechanisms) narrow the senses. For example, usage distinctions can be made based on macroscopic swallowing of detritus (as an earthworm does) versus microscopic lysis of detritus (as a mushroom does).