Microaerophile

A microaerophile is a microorganism that requires oxygen to survive, but requires environments containing lower levels of oxygen than are present in the atmosphere (i.e. <21% O₂; typically 2–10% O₂). Many microaerophiles are also capnophiles, requiring an elevated concentration of carbon dioxide (e.g. 10% CO₂ in the case of Campylobacter species).

Microaerophiles can be cultivated in candle jars. Candle jars are containers into which a lit candle is introduced before sealing the container's airtight lid. The candle's flame burns until extinguished by oxygen deprivation, creating a carbon dioxide-rich, oxygen-poor atmosphere. Other methods of creating a microaerobic environment include using a gas-generating pack and gas exchange.

...
Wikipedia