On 14 Mar 1999 04:01:21 -0800, khlee at MED.CHUNGBUK.AC.KR <khlee at MED.CHUNGBUK.
>><P>I am trying to express a recombinant protein on pATH vector (TrpE promoter)
>in E. coli.
><BR>This protein will be induced in M9 media, which contains casamino acid
>in 0.5% (5g/L) as usual concentration.
>><P>(1) I wonder if I can increase the yield of recombinant protein when
>I increase the concentration of casamino acid in M9 media.
>><P>(2) In addition to the minimal salt, I usually add glucose, thiamine,
>calcium and magnesium. Is it required to increase the concentration of
>salt and other additives if the concentration of casamino acid shall be
The answer to your questions can be determined experimentally using design
of experiments (DOE). DOE is a method for systematically varying the
system parameters (i.e. medium composition) so as to find the optimum
output (i.e. yield of recombinant protein).
The advantages to using DOE are that it is faster and easier than
traditional methods and you generally obtain more useful information. If
you are interested, let me know and I will send more information.
rbb at nebiometrics.com