saprophyte

This term is primarily used in biological and ecological contexts to describe organisms that perform the critical role of decomposition. It carries a neutral, scientific connotation, focusing on the nutritional strategy of the organism rather than the "gross" nature of decay. It is often contrasted with parasites, which feed on living hosts, and autotrophs, which produce their own food.

In academic writing, it is frequently used to categorize specific fungi and bacteria within a nutrient cycle. While the term is precise, in casual conversation, people are more likely to use the broader term "decomposer."