Mutants of incapable of utilizing citrate (C −) were discovered in glucose cultures by a modification of the mutant-concentrating penicillin technique. These C− mutants utilize glucose as efficiently as does the wild-type (C +), despite their inability to utilize a wide range of other metabolites as carbon sources for growth, including compounds that would be oxidized if glucose were aerobically dissimilated via the Krebs cycle. The compounds that the C − mutants cannot utilize are citrate, α-ketoglutarate, glutamate, succinate, fumarate, aspartate and acetate, which are all substrates to which glucose-grown C + cells slowly adapt. A non-genetic loss of ability to grow in media containing these substrates also occurs in glucose-grown populations under certain conditions. The C − mutant can revert to the prototrophic condition directly, or indirectly by first mutating to a stable state (C− F +) in which fumarate and aspartate can be utilized whereas the other compounds cannot.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred