From The Aquarium Wiki
Nitrate respiration is the process where anaerobic bacteria (usually in the substrate) consumes nitrate instead of oxygen to to fulfil their reproduction needs and release nitrogen gas which may convert to nitrite in water.
Typical bacteria that do this Pseudomonas denitrificans, P. aeruginosa, P. stutzeri, and Micrococcus denitrificans.
Some companies sell products that use this feature of anaerobic bacteria to reduce nitrate to zero or low levels.
- AZNO3 - Absolute Zero Nitrates
- EasyBalance, NitrateMinus.