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Title: Investigation of the fixation of nitrogen by micro-organisms, with special reference to the metabolism of ammonia by Azotobacter vinelandii
Author: Hanif, Anwar Hussain
Awarding Body: University of London
Current Institution: Imperial College London
Date of Award: 1966
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During this research work the author has developed the shaking culture incubator for the basic requirements of micro-organisms while growing the Azotobacter vinelandii in two different synthetic media in order to study the fixation of nitrogen by micro-organisms with special reference to the metabolism of ammonia . The intra-and extra-cellular pool of nitrogen compounds were examined and the effect on growth and fixation of addition of nitrogenous substances to the extra-cellular pool using cultures in various states of training with respect to the substrates . The. results obtained using bacteriological, analyticall paper chromatographic and ion-exchange chromato- -graphic methods were finally confirmed by using isotopically labelled ammonium and gaseous nitrogen substrates. There were no previous reports in which '0' strain has been grown in synthetic media 'Ficoll' to facilitate comparison of this nature . As previously suspected by Wusteman and confirmed by the author the only possible candidates as intermediates in fixation were ammonia, glutamic acid and the two amides and these were added to form an artificial extracellular pool in growing cultures . Fixation and ammonium uptake occur simaltaneously in trained cultures . The implications of this are confirmed by results presented in this thesis, which show that as proposed previously, free ammonium can no longer be regarded as an obligatory intermediate in the fixation process.
Supervisor: Roberts, E. R. Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available