Use of nitrogen fixing organisms as sustainable producers of nitrogen fertilizers is beneficial for the ecosystem. In addition, the nitrogen produced by the nitrogen fixing organsims is less exposed to situations where it can be denitrified and leached to the atmosphere.The relevance of using nitrogen fixing organisms is that it is 1) cheaper than use of industrially produced nitrogen fertilizers, 2) a sustainable source of nitrogen and 3) less pollutants are being produced.

Feather moss-cyanobacterial association

Very recently I discovered together with Profs Zackrisson and Nilsson, Swedish Agricultural University and Asoc. Prof. DeLuca, Montana, a new association between the very common feather moss Pleurozium schreberi and a cyanobacteria. The cyanobacteria is aible to fix app. 2 kg N/ha/year, and therefore contibute to the nitrogen pool of that ecosystem.

 

Frankia

The actinomycete Frankia is a soil organism with the ability to fix nitrogen from the atmosphere in free-living as well as in symbiotic conditions. In nitrogen fixing organisms the enzyme nitrogenase catalyze the nitrogen fixation process. However, it also produces hydrogen, which is is beeing evolved as a waste of energy.

Hydrogenases

Some Frankia has been shown to have an enzyme, uptake hydrogenase that oxidizes the hydrogen evolved from nitrogenase, and thereby regaining energy. Uptake hydrogenase is immunologically related to [Ni-Fe]-hydrogenases in other organisms.However, the biodiversity of the hydrogenases in Frankia is not known.