Hello,
For a titer determination of the U3 e.coli k12 Gal+ phage, I need to know what the maximum salinity for the k12 Gal+ strain is. Poory I can't find any research on this. Any experiences?
I want to use elevated salinity for easier sterilisation, this will be needed to show the practical use of phage farming for pharmacy.
Thanks very much,
regards,
André Leonhardt
Hello Andre, it's simple. Prepare a stock solution of say 5M NaCl and run dilutions say 2-fold, 5-fold and 10-fold dilutions. Repeat these dilutions making the first set of dilutions your stock solutions. This will give you several dilutions from the original 5M NaCl solution. Expose a standardized bacterial suspension from an 18-h old Luria broth (tryptic soy broth works well) culture to these different NaCl concentrations until you arrive at the concentration where no single colony develops on the plate. The concentration just before the one with no colony is the maximum salinity. You have to determine your concentrations by yourself.
I think I may begin with a -.5M NaCl solution and test it up to 2M NaCl with 0,5M steps. I think if even 1.5M work, I will just use it, I mean most bacteria at this salinity will be killed off easily or have to be adapted to maintain the osmotic pressure. (As long as I don't use halophiles of course)
I hoped I could find some concrete answers but I think I have to chug the bitter pill and test it out
I suggest to test it by yourself to get the concret answer because growth behaviour of the same strain could be different even if you used the same conditions due to different isolates of the same species. You can use a wide range of salinity like 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3 M of NaCl in order to get a complete idea on its impact.
Best wishes
You have to determine it on your test strain as the behaviour might differ among different strains within the same species (strain and growth conditions- dependent results)
Just prepare a serial dilution of NaCl in the suitable growth medium and inoculate it with a standardized (1-2×105) inoculum for 16-24 hrs.
Good luck
- Badges
- Science topic
- Similar topics
- Biology