01366naa a2200193 a 450000100080000000500110000800800410001902400440006010000140010424500860011826000090020452008070021365000170102065000220103770000140105970000190107370000190109277300610111121351962021-10-08       1981    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.1007/BF004110582DOI1 aBOTHE, H.  aTransformations of inorganic nitrogen by Azospirillum spp.h[electronic resource]  c1981  aAzospirillum spp. participate in all steps of the nitrogen cycle except nitrification. They can fix molecular nitrogen and perform assimilatory nitrate reduction and nitrate respiration. Culture conditions have been defined under which nitrate is used both as terminal respiratory electron acceptor and as nitrogen source for growth. Nitrate and, possibly to a very limited extent, nitrite, but not sulfate, iron or fumarate support anaerobic respiration. Under anaerobic conditions, nitrate can also supply energy for nitrogen fixation but without supporting growth. Nitrate-dependent nitrogenase activity lasts only for 3-4 h until the enzymes of assimilatory nitrate reduction are synthesized. Nitrite accumulates during this period and inhibits nitrogenase activity at concentrations of about 1 mM.  aAzospirillum  aNitrogen fixation1 aKLEIN, B.1 aSTEPHAN, M. P.1 aDOBEREINER, J.  tArchives of Microbiologygv. 130, n. 2, p. 96-100, 1981.