The role of Azospirillum spp. like nitrofixing asociative bacteria

Abstract

Rizobakterije stimulativno djeluju na rast biljaka, te smanjuju ili štite biljke od bolesti, a najčešće se označavaju kao PGPR (Plant Growth Promoting Rhizobacteria). U prirodi postoji kružni tok dušika gdje je atmosfera izvor dušika kojega u tlo transformiraju mikroorganizmi prilikom procesa koji se naziva fiksacija dušika. Biološka fiksacija dušika je proces u kojem posebne skupine mikroorganizama usvajaju elementarni dušik iz atmosfere i reduciraju do amonijaka. Asocijativni fiksatori aktivni su na površini korijena, a ovim fiksatorima pripadaju bakterije roda Azotobacter, Azospirillum, Bacillus, Klebsiella. Bakterije roda Azospirillum imaju važnu ulogu kao nitrofiksatori. Svojom aktivnošću potiču rast biljaka, poboljšavaju rast i razvoj korijena, povećavaju usvajanje vode i mineralnih hraniva, utječu na mikrobiološke procese u tlu. Također utječu na produkciju bioloških tvari.Rhizobacteria stimulate plant growth, and reduce or protect plants from disease, most often referred as PGPR ( Plant Growth Promoting Rhizobacteria ). In nature there is a roundabout where the nitrogen source is a nitrogen atmosphere in which the microorganisms in the soil transform process called nitrogen fixation. Biological nitrogen fixation is a process in which specific groups of microorganisms adopt elemental nitrogen from the atmosphere and reduced to ammonia. Associative fixators are active on the surface of the root, and the fixators belong to bacteria of the genus Azotobacter, Azospirillum, Bacillus, Klebsiella. Bacteria of the genus Azospirillum play an important role as nitrofixing. Its activities stimulate the growth of plants, enhance the growth and development of roots, increasing the adoption of water and mineral nutrients, affect the microbiological processes in soil. Also affect the production of biological substances