Phages capable of transducing succinate dehydrogenase mutants () of were isolated from pools of artificially constructed recombinant lambda phages using a selective casein digest medium. These phages produced characteristically dense turbid plaques, and as prophages they increased the aerobic growth efficiencies of mutants on complex media but were unable to promote growth with succinate as sole carbon and energy source (an essential feature of strains). The phages were identified as fumarate reductase transducing phages (λ) by the presence of a characteristic 4.9 kilobase pairs R. dIII fragment of bacterial DNA, the expression of a polypeptide with a relative molecular mass of 72000 (the gene product) and by comparing their transducing activities with authentic λ phages. In parallel studies a strain containing a ColE1- hybrid plasmid (pGS1 = pLC16.43) was characterized. Transfer of pGS1 to mutants was accompanied by increased aerobic growth efficiencies on complex media and the ability to utilize succinate as sole carbon and energy source. It was concluded that fumarate reductase can replace succinate dehydrogenase but the extent of the reversal of the lesion depends on gene dosage and the titration of the repressor which normally prevents aerobic synthesis of the reductase.


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