Preparation of Rich Medium for cultivation of Zymomonas sp - (Apr/12/2013 )

Hello all,

I need to prepare Rich media containing glucose (RMG) for cultivation of Zymomonas sp.

Composition - Glucose - 2g
KH2PO4:- 0.2 g,
Yeast extract - 1 g,
dissolved in 100 ml distilled water.

I cannot sterilize this media using autoclaving at 121 degrees/15 min. The glucose gets charred.

Does any one have the method for sterilization using syringe filter / pressure cooker?

I do not have a programmable autoclave that can be set at 110 degrees

thanks

You can sterilize the glucose separately, cool, and mix. Alternatively, you can use an 0.22 micron syringe filter to sterilize the solution, or for larger volumes, a bottle top filter.

110° C? Does the recipe states that? Then, do it. It won't only be due the glucose but it will also affect to the YE. Where did you get the recipe from? Are you sure it is the glucose that gets charred? YE-containing media use to get darker after autoclaving and that is in direct relation with the time and temp you autoclave.

Similarly, for fungi, malt extract broth has to be autoclaved only 10 min at 115° C, and believe me, that's important.

How you cannot change the temp in the autoclave? O_o

You could try the classic technique of Tyndalization.