[Yeast] Cheap yeast extract/ proteose peptone for YPD?

[Andrew Carter]

Dear All
I saw a thread similar to my current question back in the 
mid 90s, but was wondering if anyone has an update.
We currently buy yeast extract and proteose peptone from 
Becton Dickinson (via Fisher) for making YPD.  However I 
am beginning to do some large scale fermenter growths and 
the cost is getting prohibitive.  I notice that there are 
much cheaper versions available (eg Sigma yeast extract 
REF 09182 is almost 5 times cheaper per kg than Bacto 
Yeast Extract).  My question is whether anyone can 
recommend a good (and cheap) combination of yeast extract 
and proteose peptone that allows normal yeast growth (to a 
similar OD etc).

Alternatively does anyone have any good ideas about cheap 
media receipes for growing yeast to very high density in a 
fed-batch fermenter run?  Anyone ever tried using malt 
extract (from a brew shop - seems cheap) for a protein 
expression related project?

Many thanks and best wishes
Andrew