John,
The sad fact is that the E. coli need that carbon! With minimal media
you are asking the bugs to transform the media components into the
empirical formula which is them (CxNyOz etc) and they cannot make more
cells if they don't have building blocks! I have had some decent results
using MOPS media with C13 acetate but glucose works much better. Other
than squeezing out more labeled protein from the given mass of cells
there is nothing that can be done about having to feed your E. coli.Some
approaches include limiting on phosphate, which greatly effects DNA
sysnthesis and cell growth while still allowing protein production, to
some degree. You can get very fancy with the mass balance, but the
easiest route is to pay your bugs for an honest days work and spend the
money, no such thing as a free lunch etc, etc...
good luck
Ted Michelini
Institute of Molecular Biology
University of Oregon
tedm at darkwing.uoregon.edu
