Actinomycete

Part of speech: noun

Pronunciation: /ˌæktɪnəˈmaɪsiːt/

Definitions

1. A filamentous microorganism that belongs to a division of bacteria, often involved in the breakdown of organic matter and the production of biologically active compounds
2. A bacterium characterized by a thread-like structure that plays an essential role in nutrient cycling and has the capability to synthesize antibiotics
3. A type of thread-like bacteria that contributes to the decomposition of organic materials and is known for its ability to generate antibiotics

Etymology: The word is a compound built from two Greek-derived elements. The first, "actino-", comes from Greek "aktis" (genitive "aktinos"), meaning "ray" or "beam", and is the same root that gives English "actinic", used of light that triggers chemical change. The second, "-mycete", comes from Greek "mykes", meaning "fungus", which is why the name sounds like a fungus even though these organisms are bacteria. The naming is a little misleading on purpose of history. Early observers saw these organisms growing as branching, thread-like filaments, which looked like the hyphae of moulds and mushrooms, so they were grouped with the fungi. Their radiating colonies, with fine threads spreading outward from a centre, suggested the "ray" element, and the two halves were joined into one term. Later microbiology showed they are prokaryotes, closer to ordinary bacteria, but the name stayed.