An E.coli that has a high expression of the lac operon
specifically high expression of the lac-permease and b-galactosidase
proteins), and hence has unrestricted growth on lactose. However (and
heres the cruncher) the strain must also have mutations in its pts
carbohydrate system (specifically HPro and enz1) so it cannot utilise
pts carbohydrates to any great extent compared to lactose and must
also have mutations in its galactose permease system so it cannot
readily use galactose as a carbohydrate source.
That is does a strain exist that can preferentially use lactose over
other common carbohydrates as a primary energy source?
Where is this strain?
(Sorry for the cross-post; a (polite) recommendation about appropriate
groups would be appreciated.)
Please reply by *mail* to jeffric at kea.lincoln.ac.nz