Induced Biochemical Mutants of Azotobacter agilis

Induced biochemical mutants to Azotobacter agilis.

Nitrogenaseless mutants of Azotobacter vinelandii.

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 ...

Metabolic Studies of Azotobacter Agilis by the Use of a Mutant Deficient in Pyruvic Oxidase*

An account has been given elsewhere of the successful isolation of physiological x-ray mutants of Azotobacter agilis with genetic blocks in the substrate oxidation mechanisms (1). The present paper deals in greater detail with a mutant strain, designated A13, that was isolated as a variant unable to grow on glucose, and gives the methods used to characterize the particular deficiency responsibl...

Mutants of azotobacter that do not fix nitrogen.

Stable strains of mutants of Azotobacter that do not fix nitrogen are difficult to obtain by traditional procedures (Karlsson and Barker, 1948; Lindstrom, 1948). Stumbo and Gainey (1938) demonstrated that culturing Azotobacter on a high nitrate medium resulted in strains that failed to fix nitrogen even after continued transfer in the absence of fixed nitrogen. However, since these strains were...

Biochemical Mutants of Bacterial Viruses.

Two years ago T. F. Anderson (1945a) reported the remarkable discovery that certain strains of bacterial virus (T4 and T6) require organic substances as cofactors for the process of adsorption of the virus on the bacterial host strain B of Escherichia coli. Tryptophan in its L form is the substance most active in promoting adsorption of phage to bacterium, about 1 ,ug per ml being sufficient fo...