Lactobacillus Isolation and Identification - (Aug/23/2011 )

Hi forum members,

I'm working on probiotic project. Currently I'm isolating bacteria from dairy product. Recently, I sampled a commercial yogurt product which claimed to have acidophilus, thermophilus and bifidobacteria. Using MRS broth and plated to MRS agar, the only species obtained were probbably yeast and cocci. a few plates do have lactobacillus but mixed with yeast. I have sub-cultured the bacteria 4x so far by re-streaking for single colony on MRS agar but still, I only obtained yeast mixed with cocci and bacilli. Please help me, if anyone knows on any specific media to isolate bifido and lactobacillus. I attached herewith the image of my gram staining for reference.

Check

http://www.anaerobes...-Selective-Agar
http://www.bd.com/eu...A/PA-254546.pdf

http://www.sciencedirect.com/science/article/pii/S0167701297000250 (it can also be used for yoghurt)
http://www.ncbi.nlm.nih.gov/pubmed/9921834

There are some researchpapers out there that speak about specific media for bigidobacteria or lactobacillus.

Take for example this paper: http://www.ncbi.nlm....icles/PMC91699/
its specifically speaking about the isolation of Bifidobacterium spp. from yoghurt...
I dont see why you only used MRS till now.