No, Alcaligenes faecalis will not grow on MacConkey agar. MacConkey agar is selective for gram-negative bacteria that ferment lactose. Alcaligenes faecalis is a gram-negative bacteria that does not ferment lactose, so it will not grow on MacConkey agar.
If no growth appeared on MacConkey agar, it may indicate that the organism does not ferment lactose or it is not a gram-negative bacterium. If no growth appeared on EMB agar, it may suggest that the organism does not ferment lactose or it is not a coliform bacterium. Further testing would be needed to identify the organism.
Moraxella is a fastidious organism and may grow on MacConkey agar, but not as well as it would on media specifically designed for its growth, such as blood agar. MacConkey agar is selective for Gram-negative bacteria that ferment lactose, which may not support the growth of Moraxella well as it is usually non-lactose fermenting.
MacConkey agar contains agar as a solidifying agent which solidifies at room temperature to provide a solid surface for bacterial growth and colony isolation. MacConkey broth, on the other hand, does not contain agar and remains liquid at room temperature to allow for easier culture of bacteria in liquid medium for metabolic studies or growth analyses.
E. coli ferments lactose on MacConkey agar, producing acid that turns the colonies pink due to the pH indicator. Pseudomonas does not ferment lactose, so its colonies remain colorless on MacConkey agar. This difference in lactose fermentation ability is due to variations in their metabolic processes and enzyme production.
The conclusion drawn if no growth appeared on MacConkey agar and EMB agar after inoculation of the media and an incubation period could be the bacteria used was possibly a Gram positive non-enteric sample.
No, Alcaligenes faecalis will not grow on MacConkey agar. MacConkey agar is selective for gram-negative bacteria that ferment lactose. Alcaligenes faecalis is a gram-negative bacteria that does not ferment lactose, so it will not grow on MacConkey agar.
If no growth appeared on MacConkey agar, it may indicate that the organism does not ferment lactose or it is not a gram-negative bacterium. If no growth appeared on EMB agar, it may suggest that the organism does not ferment lactose or it is not a coliform bacterium. Further testing would be needed to identify the organism.
Moraxella is a fastidious organism and may grow on MacConkey agar, but not as well as it would on media specifically designed for its growth, such as blood agar. MacConkey agar is selective for Gram-negative bacteria that ferment lactose, which may not support the growth of Moraxella well as it is usually non-lactose fermenting.
Macconkey agar consists of agar, lactose, peptone, neutral red dye, crystal violet dye & bile salts. Bile salts inhibit growth of Gram positive bacteria & allow growth of Gram negative bacteria only. It differentiates lactose fermentating Gram negative bacteria from non lactose fermentating Gram negative bacteria.
Undefined.
MacConkey agar
Lac+ bacteria is acid base color indicator that lowers the pH of the MacConkey agar. The MacConkey agar contains neutral red dye, lactose, peptone, and crystal violet dye.
Most gram positive bacteria do not grow on MacConkey agar or Eosin Methylene Blue (EMB) agar, as these are selective media designed to inhibit the growth of gram positive organisms. So, typically, you would not expect a gram positive bacteria to grow on these media.
MacConkey agar contains agar as a solidifying agent which solidifies at room temperature to provide a solid surface for bacterial growth and colony isolation. MacConkey broth, on the other hand, does not contain agar and remains liquid at room temperature to allow for easier culture of bacteria in liquid medium for metabolic studies or growth analyses.
MacConkey agar is designed to grow Gram-negative bacteria and also contains crystal violet dye which inhibits the growth of Gram-positive bacteria. Since S. aureus is Gram-positive it should not grow on MacConkey agar. No. MacConkey agar inhibits MOST of the Gram-positive bacteria. There are some Gram-positive bacteria that can tolerate bile-salt are able to grow in MacConkey agar. Enterococcus and some species of Staphylococcus are able to grow in MacConkey. (lack citation though)
Enterococcus faecalis typically does not grow on MacConkey agar as this selective and differential medium is primarily used for isolating and differentiating members of the Enterobacteriaceae family, which are mostly gram-negative bacteria. Enterococcus species are gram-positive bacteria and do not ferment lactose, the key ingredient in MacConkey agar that allows for differentiation.