SUMMARY: A study (Fincham, 1950 of two mutant strains of , which probably owed their origin to independent occurrences of mutation at the same locus, showed them to be deficient in their ability to synthesize from ammonia the -amino groups of a wide range of amino-acids. They grew well when any one of a number of different -amino-acids was added to the medium, but would only grow slowly, and after a prolonged lag-phase, in the absence of amino-acid. The corresponding -amino-acids and -keto-acids were inactive in promoting growth. The mutants were subnormal in their capacity to assimilate ammonium nitrogen. In the present study the -glutamic acid dehydrogenase activity of dialysed extracts of strains carrying the amination-deficiency mutation, and of a number of other wild-type and mutant strains, was investigated. All strains, with the exception of the amination-deficient strains, yielded an -glutamic acid dehydrogenase specific for coenzyme II. Extracts of four amination-deficient strains had no detectable glutamic dehydrogenase activity, and did not inhibit the enzyme appreciably when added to wild-type extracts. Glucose-6-phosphate dehydrogenase was present in one extract tested for its presence.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error