LB Broth Alternative

Discussion in 'Supporting Biology' started by Omni, Mar 3, 2020.

  1. Our students are carrying out a PAG that requires LB Broth - but it is going to cost over £50 to buy the broth with postage and packaging - does anyone know an alternative to LB Broth. Thanks
  2. Make your own if you have the ingredients
    H2O 950 mL
    Tryptone 10 g
    NaCl 10 g
    Yeast extract 5 g
    Combine the reagents and shake until the solutes have dissolved. Adjust the pH to 7.0 with 5 N NaOH (~0.2 mL). Adjust the final volume of the solution to 1 L with H2O. Sterilize by autoclaving for 20 min at 15 psi (1.05 kg/cm2) on liquid cycle.
    For solid medium, add 28g Agar
    Omni likes this.
  3. I just used the usual nutrient broth for this PAG that I usually use for subculturing. Worked fine.
    Last edited: Mar 4, 2020
    Omni likes this.
  4. Few schools will have the Tryptone due to its expense. It sounds to me that you are attempting to grow the bacteria found in live yoghurt.. I have succeded in growing them on Nutrient agar plates supplemented with 1% glucose and 1% marmite (yeast extract). Indeed a couple of weeks ago when we did transformation of E. coli with the pGlo plasmid I tried growing the un transformed E. coli and transformed E. coli on Nutrient agar instead of the LB agar and they grew incredibly well.

    Omni likes this.
  5. I would just grow them in sterilized milk.
    Omni likes this.
  6. A nice idea Paul, but the bacteria (L. casei) are particularly fussy and prefer a richer medium.

    Omni likes this.
  7. yakult will disagree with you.

    can't be that fussy
    Omni likes this.
  8. Yakult is heavily enriched with glucose and fructose.
    Omni likes this.
  9. And the Gut Paul.:)
  10. We carried out this PAG a couple of weeks ago and chose to use nutrient broth instead of LB. We got the desired results from this and couldn't see why they were specifying LB. I think they just like to throw in the occasional curveball, just because they can.
  11. Not a curveball as such Lynda - it's just that some bacteria prefer this medium for good growth whereas if you grow the same bacteria on bog standard Nutrient agar you get very poor growth.:)