01382naa a2200205 a 450000100080000000500110000800800410001910000190006024500400007926000090011952008690012865000120099765300200100965300200102965300160104965300260106570000220109170000200111377300430113312057382020-01-08       1986    bl uuuu     u00u1 u    #d1 aRUSCHEL, A. P.  aHydrogen uptake by Azolla-Anabaena.  c1986  aExperiments under laboratory conditions were carried out with the objective of studying hydrogen uptake in the Azolla-Anabaena system. Tritium was used as tracer and plants were incubated under different atmospheric composition: a) Air + 3H2; b) Air + 3H2 + CO; c) Air -h 3 H2 -I- CO, d) Argon -1- 3 H2 + C02 -I- CO and in presence and absence of light, to study hydrogen uptake via hydrogenase and nitrogenase activity. Azolla-Anabaena showed greater hydrogen uptake under argon atmosphere than under air. Carbon monoxide decrease hydrogen uptake as well as nitrogenase activity. Under dark conditions, nitrogenase activity was smaller under argon than air atmosphere. Carbon monoxide decreased hydrogen uptake. H2 -uptake was not affected by light, as it occurs under dark conditions. There are evidences of recycling of the hydrogen evolved through nitrogenase.  atritium  aAzolla-Anabaena  aHydrogen uptake  aHydrogenase  aNitrogenase acitivity1 aFREITAS, J. R. de1 aSILVA, P. M. da  tPlant and Soilgv. 97, p. 79-83, 1986.