I have another commitment right now and will give you a full reply later today. Sorry for the inconvience
Thank you for your response. Later today will be great. Is what I need help with clear from the information i have given you?
Let me know if this answers your questions.I've never tried growing the organisms at 15% NaCl, so have no direct experience with that concentration, but the literature seems to point to the results I've outlined
Even pure strains of the bacteria can have genetic mutations that allow them to tolerate different saline concentrations or ferment unusual compounds, nothing is 100% in microbiology, but that is the fun part.
VP TestAdd potassium Hydroxide + creatine (KOH) & alpha-naphthol, Shake vigorously, let stand ~ 5-10 minutes, some references indicate1-2 hours, exposed to air.
Negative (-) = light brown color, (E. coli), Positive is a pink color (Enterobacter)
MR-VP, usually run at the same time, Record the MR results (red+, yellow -) before adding the VP reagents
The corresponding Methyl Red test is Positive for E.coli (red) and Negative for Enterobacter
Staphylococcus epidermidisFructose Positive (Ferments)Glucose Positive (Ferments)Mannitol Negative (Staph aureus is Positive)Motility Non Motile (Staph are cocci (round) and are not motileSalt Tolerance 1% GrowthSalt Tolerance 7% GrowthSalt Tolerance 15% slow or no growth
Saccharomyces cerevisiae Fructose Positive (Ferment)Glucose Positive (Ferment) (prefers Glucose over Fructose)Salt Tolerance 1% GrowthSalt Tolerance 7% Inhibition or No GrowthSalt Tolerance 15% No Growth
It appears that Saccharomyces cerevisiae cannot ferment Mannitol, although some wild strains can and the yeast can be adapted to the sugar