The reason colonies appear red on MacConkey agar is:
Question 1 options:
The organisms digest lactic acid and produce lactose which is red
The organisms digest lactose and produce lactic acid which is red
The organisms digest lactose and produce lactic acid which changes the pH indicator from colorless to red
The organisms digest lactic acid and produce lactose which changes the pH indicator from colorless to red
Related textbook solutions
Related questions
microbiology double unknown
1. G+ coccus
*tiny colonies
*white colony
*sediment
*Phenol Red:
PR Glu: (A/-) Yellow
PR Lac: (A/-) Yellow
PR Suc: (A/-) Yellow
*SIM test
Sulfure reduction: (-) No black
Indol: (-) No pink
Motility: (+)
*MR: (+) Red
*VP: (+) Red (redish brown)
* Red blood agar: beta hemo
*MacConkey: (-) No growth (G+)
*DNAse: (+) clearing around
*Gelatin: (+) liquid in 5 days
*Nitrate reduction: (+) red when added 2 indicators
*Citrate: (-) green
*Casein: (-) unclear
* EMB: (-) no growth
*MSA: (+) with yellow halo
*starch: (-) no clear around
2. Gram - bacillus
*tiny colonies
*yellow and sometimes red color inside of colony
*colony forming unit: Flocculent
*oxidase: (-) no blue
*Phenol Red
PR Glu: (A/-) Yellow
PR Lac: (-/-) No color change
PR Suc: (A/-) Yellow
*SIM test
Sulfur reducation: (-) No black
Indole: (-) no pink
motility: [+] little growth inside
*MR: (-) No color change
*VP: (+) red (red on the top and yellow on the bottom)
*Red blood cell Agar: alpha hemo
*MacConkey: G- and no color change (No fermentt lactose/noncoliform)
*DNAse: (+) clearing around
*Gelatin: (+) in 1 day
*Nitrate: (+) red after adding indicators
*Citrate: (+) blue
*Casein: (+) clear ........... (NOT SURE)
*EMB: poor growth
*MSA: (+) with yellow halo
*TSI: (A/A)(NG) yellow top and bottom, no gas
*Starch: (+) clear around after adding indicator
What is thename of Gram+ and Gram- Bacteria?
My instiructor gave us this bacteria list (he said someunknown bacteria can be not on the list)
| B. Cereus |
| E. coli |
| E. aerogenes |
| E. faecalis |
| Streptococcus bovis |
| K. pneumoniae (pneumoniae |
| S. aureus |
| S. epidermidis |
| Moraxella Moratella Osloensis |
| P. vulgaris |
| B. subtilis |
| M. luteus |
| P. aeruginosa |
| Bacillus Alvei |
| S. marcescens |
| A. faecalis |
| Staphylococcus Saprophyticus |
| Alcaligenes latus |
| Morganella morganii |
| S. sonnei |
| C. xerosis |
| Listeria innocua |
| Proteus mirabilis |
| Streptococcus agaloctiae |
| Salmonella Choleraesais |
| S. mitis |
