Lithotrophic prokaryotes

Physiological group	Energy source	Oxidized end product	Lithotrophic organism
methanogens	H2	H2O	Methanobacterium
hydrogen bacteria	H2	H2O	Alcaligenes, Pseudomonas
carboxydobacteria	CO	CO2	Rhodospirillum, Azotobacter
nitrifying bacteria*	NH3	NO2	Nitrosomonas
nitrifying bacteria*	NO2	NO3	Nitrobacter
sulfur oxidizers	H2S or S	SO4	Thiobacillus, Sulfolobus
iron bacteria	Fe ++	Fe+++	Gallionella, Thiobacillus

* The overall process of nitrification, conversion of NO3 to NH3, requires a consortium of microorganisms.