I am studying the growth and acid tolerance of various E. coli strains. I am growing cells in minimal media containing glycerol as a carbon source. During this study, I have noticed that E. coli RR1 has not shown any growth. Does anybody have experience with E. coli RR1 with glycerol? If so, do you have any advice?
Dear Mukesh, I have studied growth study of bacteria in minimal media with glycerol as carbon source, but those strain were hydrocarbon utilizing strain and hence they exhibited high growth on glycerol as carbon source, I will suggest you to give very low concentration of glycerol to start with and also increase your inoculum
RR1 carries a number of mutations. It is auxotrophic for proline and some genotypes list an auxotrophy for leucine as well. So you should try adding those two amino acids to your minimal medium. Also most E. coli K12 strains require vitamin B1 (thiamine) which needs to be added to minimal medium.
Hi, I think this strain is a derivative of HB101. The only difference is that is recA+. Here you have the phenotype F-, araC14, leuB6(Am), Δ(gpt-proA)62, lacY1, glnV44(AS), galK2(Oc), λ-, rpsL20(strR), xylA5, mtl-1, thiE1, [hsdS20]
It is not a good strain for minimal media. Maybe Michael is right, just by adding this two amino acids you have growth, but then maybe bacteria prefer to use amino acids as carbon source instead of glycerol. If it is all about acid tolerance, I advise, if possible to change to a rich media unless you want to keep out your auxotrophic strains. Good luck.
you can try to add casamino acids fas a supplement to your minimal medium, most auxotrophic strains grow well with it except for Tryptophan auxotrophs.
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