Crème Fraiche - Using As Mesophilic Starter Culture?

[jonburt86]

I wondered if anyone could give me some pointers with respect to starter cultures...

As you can tell I'm new to all this but I need to sort something out to acidify the milk. Basically I could do with a mesophyllic starter culture. As I haven't been able to get my hands on cultured buttermilk, I wondered if creime fraiche would serve as a mesophyllic starter instead...

Any information would be much appreciated!