What is the end products of mannitol fermentation?
Pentoses, if fermented, are converted into acetic and lactic acids. Glucose and the ot,her aldoses yield chiefly ethyl alcohol, lactic acid, and carbon dioxide. Resides mannitol, acetic acid, lactic acid, and carbon dioxide are formed from fruc- tose.
What acid does mannitol fermentation?
Conclusions: The production of individual organic acids was dependent on growth and the fermentability of prebiotics. Mannitol, FOS and inulin favoured the production of formic, lactic and butyric acids respectively.
Can mannitol be fermented?
If an organism can ferment mannitol, an acidic byproduct is formed that will cause the phenol red in the agar to turn yellow. Most pathogenic staphylococci, such as Staphylococcus aureus, will ferment mannitol. The Staphylococcus aureus ferments mannitol and turns the medium yellow.
What does a positive mannitol fermentation test mean?
An inoculum from a pure culture is transferred aseptically to a sterile tube of phenol red mannitol broth. The inoculated tube is incubated at 35-37 C for 24 hours and the results are determined. A positive test consists of a color change from red to yellow, indicating a pH change to acidic.
What can you conclude about the pictured bacteria?
The pictured bacteria probably produce lipopolysaccharide (LPS), also known as endotoxin. What can you conclude about the pictured bacteria? If a Gram stain was performed on this bacterium within 24 hrs of a fresh culture, it would most likely be Gram-positive.
Is MSA selective or differential?
This type of medium is both selective and differential. The MSA will select for organisms such as Staphylococcus species which can live in areas of high salt concentration (plate on the left in the picture below).
Does Lactobacillus Ferment mannitol?
Lactobacillus intermedius B-3693 was selected as a good producer of mannitol from fructose after screening 72 bacterial strains. The bacterium produced mannitol, lactic acid, and acetic acid from fructose in pH-controlled batch fermentation.
Does Streptococcus ferment mannitol?
Staphylococcus species are halotolerant, whereas Streptococcus species and many other organisms are inhibited by high concentrations of NaCl. MSA also differentiates on the basis of mannitol fermentation.
Does Staphylococcus epidermidis ferment mannitol?
Staphylococcus epidermidis grows on MSA, but does not ferment mannitol (media remains light pink in color, colonies are colorless).
Does Staphylococcus Saprophyticus ferment mannitol?
Staphylococcus saprophyticus (coagulse-negative Staphylococci) may ferment mannitol, producing yellow halo around colonies in MSA thus resembling S. aureus.
What can you conclude about the acid fast stain specimens?
What can you conclude about the Acid-Fast stained specimen? The mycolic acids in the cell walls of acid-fast bacteria make them resistant to acid-alcohol.