Saprotroph

From Encyclopedia Jr, free information reference for Kids

A saprotroph (or saprobe) is an organism that obtains its nutrients from non-living organic matter, usually dead and decaying plant or animal matter, by absorbing soluble organic compounds. Since saprotrophs cannot make food for themselves, they are considered a type of heterotroph. They include many fungi (the rest being parasitic, commensal or mutualistic symbionts), bacteria, and protozoa. Animal scavengers, such as dung beetles, and vultures and a few unusual non-photosynthetic plants are also sometimes referred to as saprotrophs, but are more commonly called saprophages.

Saprophyte is an older term that is now considered obsolete. The suffix -phyte means "plant". However, there are no truly saprotrophic organisms that are embryophytes, and fungi and bacteria are no longer placed in the Plant Kingdom. Plants that were once considered saprophytes, such as non-photosynthetic orchids and monotropes, are now known to be parasites on other plants. They are termed myco-heterotrophs because a mycorrhizal fungus connects the parasitic plant with its host plant.

Some saprotrophic organisms are useful scavengers, and in sewage farms and refuse dumps break down organic matter into nutrients easily assimilable by green plants.

[edit] Further reading

• Hershey DR. 1999. Myco-heterophytes and parasitic plants in food chains. American Biology Teacher 61:575-578.
• Leake JR. 2005. Plants parasitic on fungi: unearthing the fungi in myco-heterotrophs and debunking the ‘saprophytic’ plant myth. Mycologist 19:113-122. [1]
• Werner PG. 2006. Myco-heterotrophs: Hacking the mycorrhizal network. Mycena News 57:1,8. Available from: http://www.mssf.org/mnews/0603mn.pdf (PDF)