Nitrifying Bacteria

Nitrifying Bacteria



For example; Nitrosomonas and Nitrobacter



In nature, there is no chemolitotroph that converts

NH

to NO

in one step.



Two groups of bacteria carry out this event sequentially.



Ammonia oxidizing bacteria (oxidizes NH

to NO

)



Ammonia monoxygenase



Nitrite oxidizing bacteria (oxidizes NO

to NO

)



Nitrite oxidoreductase



There are also "anammox" bacteria. These oxidize

ammonia in an anoxygenic environment.

Sulfur and Iron Oxidizing Bacteria



For example; Thiobacillus, Acidithiobacillus,



Achromatium, Beggiatoa



Sulfur oxidizing bacteria are divided into two large ecological groups:



Those who live at neutral pH and those who live at

acidic pH.

H

Oxidizing Bacteria



For example; Ralstonia, Paracoccus



These bacteria reduce oxygen by using

hydrogen as a single electron donor.



The key enzyme in hydrogen oxidizing bacteria is hydrogenases.



These enzymes are sensitive to oxygen and their

cofactor is Nickel.



Some hydrogen bacteria can use

carbon monoxide (CO) as an electron donor and grow aerobically.



CO-oxidizing bacteria are called

carboxydotrophic bacteria

Methanotrophs and Methylotrophs



For example; Methylomonas, Methylobacter



Methane (CH

) is abundant in nature. Methane,

produced by methanogenic Archaea in oxygen-free environments, is the most important gas found in

oxygen-free mud and marshes, oxygen-free zones of lakes, rumen of ruminant animals and the digestive system of mammals.



Methane is also the main component of “natural gas”

and is found in many coal structures.