Nitrogenaseless Mutants of Azotobacter vinelandii Journal Articles

abstract

• Mutants of Azotobacter which grow normally on excess ammonia under a variety of conditions and which grow slowly or not at all on atmospheric nitrogen have been isolated. Extracts of these strains have low or no detectable nitrogenase activity. There are three classes of mutants. Cell-free preparations of members of the first class possess an enhancement factor (EF+) which stimulates wild-type nitrogenase in vitro . Homogenates of members of the second class possess an enhanceable factor (EF-) which complements in vitro with extracts of the first class of mutants to give substantial nitrogenase activity. Preparations of members of the third class contain neither EF+ nor EF- activity. EF+ and EF- are repressed by the same conditions that repress nitrogenase. Molybdenum-deficient cells of the second class of mutants do not appear to contain EF- activity, but molybdenum deficient cells of the first class of mutants contain EF+. Because of these observations, EF+ is tentatively equated to azoferredoxin and EF- to molybdoferredoxin.

authors

• Sorger, George Joseph
• Trofimenkoff, Diane

status

• published 

publication date

• January 1970

has subject area

• Azotobacter (MeSH)
• Bacteriophages (MeSH)
• Cell-Free System (MeSH)
• Ferredoxins (MeSH)
• Genetic Complementation Test (MeSH)
• Genetics, Microbial (MeSH)
• Microbial Sensitivity Tests (MeSH)
• Molybdenum (MeSH)
• Mutation (MeSH)
• Nitrogen Fixation (MeSH)
• Oxidoreductases (MeSH)

published in

• Proceedings of the National Academy of Sciences of the United States of America  Journal

keywords

• Azotobacter
• Bacteriophages
• Cell-Free System
• Ferredoxins
• Genetic Complementation Test
• Genetics, Microbial
• Microbial Sensitivity Tests
• Molybdenum
• Mutation
• Nitrogen Fixation
• Oxidoreductases

Digital Object Identifier (DOI)

• 10.1073/pnas.65.1.74

start page

• 74

end page

• 80

volume

• 65

issue

• 1