noun
- A specialized cell found in certain filamentous cyanobacteria that fixes atmospheric nitrogen.
Usage: biology; microbiology
Examples
- Heterocysts are larger and more heavily pigmented than the vegetative cells surrounding them.
- The heterocyst provides a low-oxygen environment necessary for nitrogen fixation.
- Cyanobacteria with heterocysts can convert atmospheric nitrogen into usable compounds.
- Under nitrogen-poor conditions, filamentous cyanobacteria develop heterocysts.
- The thick cell wall of a heterocyst protects the nitrogen-fixing enzyme nitrogenase from oxygen.