Chemosynthesis is a reaction that produces chemical energy, converted from the binding energy of oxidized inorganic compounds.

Chemical energy is released, used in the production of organic compounds and oxygen gas (O2) from the reaction between carbon dioxide (CO2) and molecular water (H2O) as shown below:

- First step:

Inorganic Compound + O2 → Oxidized Inorganic Compounds + Chemical Energy

- Second stage:

CO2 + H2O + Chemical Energy → Organic Compounds + O2

This process autotrophic synthesis of organic compounds occurs in the absence of solar energy.

It is a resource commonly used by some species of bacteria and archaebacteria (bacteria with primitive characteristics still in force), given the name according to the reactive inorganic compounds, which can be: ferrobacteria and nitrobacteria or nitrifying (nitrosomonas and nitrobacter, genus of chemosynthetic bacteria).
At ferrobacteria oxidize iron-based substances to achieve chemical energy, whereas nitrifying, use nitrogen based substances.

Nitrifying Bacteria

Present on the ground, nitrosomonas and nitrobacter, are important organisms considered nitrogen biofixers, usually found freely in the soil or associated with plants, forming root nodules.
Biofixation begins with assimilation into the atmospheric nitrogen (N2)by turning it into ammonia (NH3), reagent oxidized by nitrosomone, resulting in nitrite (NO2-) and energy for the production of sustainable organic substances for this genus of bacteria.
Nitrite, released into the soil and absorbed by nitrobacter, also undergoes oxidation, generating chemical energy for the production of organic substances in this genus. nitrate (NO3-), used by plants in the elaboration of amino acids.

Chemosynthetic reaction in Nitrosomones:

NH3 (ammonia) + O2 → NO2- (nitrite) + Energy
6 CO2 + 6H2O + Energy → C6H12O6 (Glucose - Organic Compounds) + 6 O2

Chemosynthetic reaction in Nitrobacter:

AT THE2- (nitrite) + O2 → NO3- (nitrate) + Energy
6 CO2 + 6H2O + Energy → C6H12O6 + 6 O2

Thus, we can see that the chemosynthesis mechanism, extremely important for the survival of nitrifying bacteria, is also very relevant to humans. As already mentioned, plant-absorbed nitrite, converted into amino acids, serves as the basis for essential amino acids to the nutrition of man (an omnivorous being: carnivore and herbivore).
Thus, the interdependence between biotic factors (the diversity of organisms) and abiotic factors (physical and chemical aspects of the environment) is evident.