I was growing Lactobacillus spp. from different yogurts using MRS agar to determine cfu/mL in different products. I also did Gram-staining and catalase test to confirm microorganisms grown are most likely Lactobacillus spp. Most of them looked like typical Lactobacillus but from one yogurt I managed to isolate some weird looking Gram+ organism. What can it be? Pictures are attached to this question.
According to manufacturer (written on the packaging), this yogurt contains: Lactobacillus acidophilus LA-5, Bifidobacterium BB-12.
Thank you in advance
This isn't culture starter of yogurt, It is probioic bacteria is use in activia product
you can selective media for bacteria identification , Please see attach file
Dear Katrina
I am interesting have you tested on growth on bacteriol agar? Lactobacillus doesnt growth on agar.
Actually, it is typical found in yogurts. Our team work on probiotic bacteria during 16 years. And very often when we analyse yogurts, we can see those microbes. But I absolutely agree, everything depends on characteristics. Mostly they prefer anaerobic cultivition
You can go for 16s RNA gene sequencing or perform API test to determine the species of bacteria based on the biochemical reactions.
Sometimes Lactobacillus acidophilus look like this.....you please go for 3-4 subculturing and use microaerophillic or anaerobic growth conditions........then grow the same culture on Rogosa-SL agar........Check morphology after every subculturing........................If still they don't look like for acidophilus. Discard them and isolate some more..............
It's lactobacillus for sure. I have exactly the same growing right now and it is growing in the presence of oxygen-I just used parafilm around the dish. I have also observed these many times on direct staining of various yogurts here in Georgia.
Hello, Katrina,
The nature of your unidentified prokaryote from yogurt can only be ascertained to a more accurate one by converging results of microscopic, biochemical, chemotaxonomic, and DNA-based assays. Microscopy will only reveal limited features of the organism.
I suggest you do PCR of 16s rRNA gene as well as biochemical characterization then compare to published literature.
All the best.
Arizaldo