E. coli Strain Request

[Michael David Jones]

Hi

We wish to use lactose (and not IPTG) to induce expression of genes cloned
into pGEX vectors (under control of the lac operator) for large scale
protein purification.  To utilise lactose, as opposed to IPTG, requires an
E. coli strain that has a wild type lac operon, wild type gal operon and
ideally ompT and lon defective to prevent protease degradation of the
expressed gene.

Anyone out there have such an E.coli strain or suggestions?  Most lab
strains appear to be mutated in the lac and/or gal operons.

Mick Jones