title: Fe protein over-expression can enhance the nitrogenase activity of Azotobacter vinelandii.
abstract: The effects of over-expression of NifH (Fe protein) on nitrogenase activity in Azotobacter vinelandii UW cells were studied by expressing an extra nifH gene under the control of the inducible meta-toluic acid pathway promoter Pm. The total amount of protein in UW/pJB654-N reacting to anti-NifH antibody was 2-3 fold of that in control UW when both the strains were grown to exponential phase in the presence of 4 μM m-toluic acid. As a consequence UW/pJB654-N showed two-fold higher acetylene reduction activity and released 70% higher amounts of ammonium into the growth medium than the control. Concomitant changes were observed also in the cellular levels of siderophores and iron superoxide dismutase (FeSOD). Thus, our results indicating that increased level of Fe protein in the cell can enhance nitrogen fixation activity of A. vinelandii may have biotechnological significance.
authors.affiliation: Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India. paprinag2003@yahoo.com
authors.forename: Papri
authors.initials: P
authors.lastname: Nag
authors.forename: Subrata
authors.initials: S
authors.lastname: Pal
mesh_terms: D000114:Acetylene / Q000378:metabolism; D016948:Azotobacter vinelandii / Q000201:enzymology*; D018628:Gene Dosage; D015870:Gene Expression; D009586:Nitrogen Fixation; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*
chemical_list: D010088:Oxidoreductases; C029130:nitrogenase reductase; D000114:Acetylene