N2N2 NO 3
Nitrification Denitrification
reduktasa dusičnanu reduktasa dusitanu
N i t r a t e r e d u c t a s e
FAD HEME MoCo NADPH + H+ NITRATE
N i t r i t e r e d u c t a s e
zdrojmnožství za rok v Mt (Tg) elektrické výboje v atmosféře < 10 biologická fixace na souších 90 – 140 biologická fixace v mořích 30 – 300 syntéza dusíkatých hnojiv 80 spotřeba fosilních paliv>20 Průmyslová fixace dusíku obnáší ročně asi 80 g (80 10 6 t), což je více než polovina množství fixovaného biologicky
The three elongated dots in the lower half of the Chinese pictogra- phic character for soybean, shu, have been postulated to signify the relationship between root nodules and plentiful growth of the plants. This character was recorded by Chou scholars in 1000 B.C.
Varro praeceptis adicit equino quod sit levissimum segetes alendi, prata vero graviore quod ex hordeo fiat multasque gignat herbas... inter omnes autem constat nihil esse utilius lupini segete priusquam siliquetur aratro vel bidentibus versa manipulisve desectae circa radices arborum ac vitium obrutis. Plinius starší De rerum natura
Varro (an earlier Roman writer) adds the employment of the lightest kind of horse dung for manuring cornfields, but for meadowland the heavier manure produced by feeding barley to horses, which produces an abundant growth of grass.... It is however universally agreed that no manure is more beneficial than a crop of lupine turned in by the plough or with forks before the plants form pods, or else bundles of lupine after it has been cut, dug in round the roots of trees and vines.]— Pliny the Elder (~A.D. 80), Natural History
The nitrogen-fixing cyanobacterium Anabaena azollae lives in leaf cavities of the floating water fern Azolla, which is deliberately introduced into the rice paddies
P-clusters of the MoFe-protein Molybdenum iron cofactor (MoFeCo)
Binding of ATP changes the conformation of the nitrogenase Fe protein