Nitrogen (N2) is the most abundant gas in the atmosphere (≈78%). The plants are nitrogen necessary for the synthesis of amino acids or protein. However, the nitrogen in the atmosphere in the form in which the plant can not adopt. The plants are only accessible in the form of ammonium and nitrate. Bacteria (so-called, fixing bacteria) and certain strains of algae having the ability to translate the (reduced) from the nitrogen of inert N2 in the form of NH4 (ammonium) and thereby make available to the plant. The bacteria that perform nitrogen fixation can be vagrants and symbionts. Symbionts living in the community with the plant, since it takes the sugar as an energy source with its own processes and plants provide nitrogen to build proteins.