saprophytic

Saprophytic describes the mode of nutrition in organisms that obtain energy and carbon by breaking down dead or decaying organic matter. The term is commonly applied to fungi and bacteria, and the organisms themselves are called saprotrophs or saprophytes. Etymologically, it combines Greek sapros meaning rotten and phyton meaning plant, though many saprotrophs are not plants.

Most saprotrophs are decomposers: they secrete extracellular enzymes such as cellulases, proteases, and lignin-degrading enzymes into their surroundings and absorb the resulting simple molecules. In fungi, hyphae penetrate decaying material and release enzymes; yeasts and bacteria act similarly on available substrates. Saprotrophy is a key step in nutrient cycling, releasing minerals and carbon back into the soil and atmosphere as CO2.

Ecological niche and distinctions: Saprotrophs contrast with parasites that feed on living organisms, and with mutualists that provide benefits in exchange for nutrients. In plants, true saprotrophy is rare; many plants historically termed saprophytes are non-photosynthetic or myco-heterotrophic, depending on fungal partners to access carbon.