Which group of bacteria reduces nitrate to nitrogen gas in the nitrogen cycle? Nitrogen fixing bacteria C. denitrifying bacteria Ammonium ion forming bacteria D. photosynthetic bacteria

C. denitrifying bacteria

Explanation:

Nitrogen cycle consists of series of processes that add and remove nitrogen from the soil and atmosphere. There are several ways in which nitrogen can be added to the atmosphere including nitrification, ammonification, lightning etc.

Certain bacteria are responsible for the conversion of nitrogen from one compound form to another. In a process called DENITRIFICATION, nitrate (NO3-), which is the usable form of nitrogen by plants, is converted back to atmospheric nitrogen (N2) with the help of a bacteria called DENITRIFYING BACTERIA e.g Pseudomonas etc.