What Types of Bacteria Produce Nitrate?

Nitrogen gas from the atmosphere is not directly available to plants.
••• symbole air image by choucashoot from Fotolia.com

Nitrogen is an element found in all proteins, and is essential for plant and animal life. Gaseous nitrogen in the air has to be fixed into compounds, either by lightning or by soil-dwelling bacteria, before it can be used by plants. These compounds include ammonia and nitrates. Animals can then take in nitrogen by eating plants. When living matter dies or nitrogen-containing wastes are excreted, bacteria and fungi convert the organic nitrogen back into ammonia.

Nitrobacter Bacteria

The bacteria species in soil that convert nitrites to nitrates all belong to the genus Nitrobacter. There are four identified species: Nitrobacter winogradskyi, Nitrobacter hamburgensis, Nitrobacter agilis and Nitrobacter alkalicus. In 2007, a phylogenetic study of the genus Nitrobacter, published in "Systematic and Applied Microbiology," identified 30 different strains for some of the species. Nitrobacter exists in soils and fresh water where the pH is moderate. It does not grow in highly acidic habitats.

Nitrosomonas Bacteria

Nitrobacter bacterial species typically occur along with bacteria from the genus Nitrosomonas in mixed bacterial communities called consortia. The two kinds of bacteria are codependent, since Nitrosomonas produces the nitrites that Nitrobacter needs, and Nitrobacter cleans up the nitrites that can suppress the Nitrosomonas if allowed to build up.

Marine Bacteria

In the ocean, there are two additional types of bacteria that oxidize nitrites into nitrates. These are Nitrococcus mobilis and Nitrospina gracilis. Nitrococcus mobilis, isolated from South Pacific waters, is a large motile coccus with unique tubular cell membranes. Nitrospina gracilis is long, slender and rod-shaped, without an extensive cell membrane system. Nitrospina has become commercially available to people who maintain saltwater aquariums, to aid in keeping nitrate levels down in tank water. The bacteria help oxidize toxic nitrites that fish produce.

Related Articles

Characteristics of Anaerobic Species
What Do Fungi Contribute to the Ecosystem?
List Some Types of Bacteria Found in Soil
Types of Bacteria on the Tongue
Cell Wall Composition of the Six Kingdoms
What Types of Fungi Grow in the Ocean?
The Effects of Sewage on Aquatic Ecosystems
How Are Bacteria a Part of Recycling & Biodegrading?
The Role of Microbes in Industry
Types of Desert Fungi
The Microorganisms Found in Sewage
What Role Do Decomposers Play in a Food Chain?
Types of Microorganisms & Optimum PH
What Are Good Protists?
What Are the Three Major Divisions of Biology?
Five Levels of the Biosphere
What Types of Bacteria Produce Endospores?
Types of Archaebacteria
What Is an Ecosystem Made Up Of?
The Chemical Composition of Nutrient Agar