Isolation of Probiotic bacteria from yoghurt - which is the best medium?? (Sep/03/2007 )

Hello
I'm planing to isolate probiotic bacteria from yoghurt samples, and I'd like to ask which is the best medium to do so.
I've looked around and almost everywhere says that MRS medium is appropriate, but is not very selective. I found medium LAMVAB on the net, but could not find the components.
Thanks for your help!!!

Hi, MRS media are selective towards Lactobacilli. However, to confirm that you are isolating the correct microbe, I suggest 16S rRNA gene analysis to complement the use of MRS media.

We asked of suppliers about the cost of MRS, and they told us that MRS is not very selective for Lactobacillus. They suggested WL nutrient agar (though the manual says it's good for brewer yeast, mostly) or Rogosa medium (for wich I couldn't previously find the recipe).
Wich one should we buy?? (I doubt my boss will let us buy all of them, or even two )