nitrifying bacterium

noun

plural nitrifying bacteria

: any of various aerobic gram-negative bacteria (as of the genera Nitrosomonas, Nitrosococcus, and Nitrobacter) commonly found in soil and water and obtaining energy through the process of nitrification

They are nitrifying bacteria, formerly believed to occur only in the soil and natural water systems, where they play key roles "fixing" nitrogen and making this element available to growing plants.

—Bernard Dixon, The Independent (London), 16 Nov. 1992

Note: Nitrifying bacteria are sometimes classified in the paraphyletic family (Nitrobacteraceae).

Word History

First Known Use

1880, in the meaning defined above

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