Effect of salt concentration on bacterial culture - (Feb/10/2009 )

I realized that my student was using L-broth pellets that contain 0.5 g/L NaCl. I read somewhere online that for growing bacteria with plasmids (we're doing MaxiPreps), it is better to use the higher salt concentrations (5-10 g/L NaCl). Does anyone here agree/disagree with that? If you have read some of my other posts, you will know that we've been having problems. Could the low salt concentration be a problem?

From experience of having to use both high salt (10g/l) and low salt (0.5g/l) due to occasional shortages... the high salt medium does give better yields than the low salt medium in the context of maxipreps.

However I don't know if it is the cause of the problem you are experiencing.

perneseblue on Feb 10 2009, 11:27 AM said:

Hi I found this post very interesting as I am currently looking into media formulations, but I am not having much luck in finding out the affect salt concentration in the media has on E. coli growth for plasmid yields. (other than sources saying salt concentrations need to be adjusted to the type of E. coli.

Could anyone point me in the direction of some sources on this topic?

We have found that LB gives the best-quality DNA, even though the yield is lower than for 2TY or other rich broths.