What does phenol red lactose broth test for?
Phenol Red Lactose Broth is used for detection of lactose fermenting bacteria.
What is the purpose of the phenol red broth test quizlet?
Phenol red broths are used to determine if a bacterium can ferment a particular sugar, and if it does ferment, if acid or acid and gas are produced.
What is a positive result from the lactose broth?
Because the same pH indicator (phenol red) is also used in these fermentation tubes, the same results are considered positive (e.g. a lactose broth tube that turns yellow after incubation has been inoculated with an organism that can ferment lactose).
What is the purpose of carbohydrate fermentation test?
The carbohydrate fermentation test is used to determine whether or not a bacteria can utilize a certain carbohydrate. It tests for the presence of acid and/or gas produced from the fermentation of a single particular carbohydrate.
What can phenol red carbohydrate broths with Durham tubes detect?
gas production
A Phenol Red Broth Base Control tube is used as a negative control for fermentation studies. A Durham tube may be inserted in a tube of Phenol Red Broth w/ Carbohydrate to allow for the detection of gas production.
What is the purpose of the Durham tube in phenol red broth quizlet?
What is the purpose of the Durham tube in the carbohydrate fermentation broth? The Durham tube is used to detect gas produced as a byproduct of fermentation. As gas forms, a bubble will appear in the tube.
What does a positive lactose fermentation test mean?
Positive: The development of a yellow color in the medium is indicative of a positive carbohydrate fermentation reaction. Negative: Lack of yellow color development is indicative of a negative carbohydrate fermentation reaction. Gas formation is indicated by the appearance of gas bubbles in the Durham tube.
What color will an organism that can ferment lactose in phenol red broth turn?
yellow
Because the same pH indicator (phenol red) is also used in these fermentation tubes, the same results are considered positive (e.g. a lactose broth tube that turns yellow after incubation has been inoculated with an organism that can ferment lactose).
Why is it important to inoculate a phenol red broth base with addition to broths containing a carbohydrate?
Microbial Biology Lab Exam 2 — Carbohydrate Fermentation. Understand why it is important to have nutrients other than the fermentable carbohydrate in a Phenol Red Carbohydrate Broth. if the bacteria cannot ferment the carborhydrate then they will die and results will be unclear.
What does a positive fermentation test mean?
What is the purpose of the Durham tube?
Durham tubes are used in microbiology to detect production of gas by microorganisms. They are simply smaller test tubes inserted upside down in another test tube. This small tube is initially filled with the solution in which the microorganism is to be grown.
What is indicated if the phenol red glucose broth stays red throughout incubation?
What is indicated if the phenol red glucose broth stays red throughout incubation? glucose is not fermented.
Why is phenol red used as a pH indicator in fermentation?
Color change only occurs when sufficient amount of acid is produced, as bacteria may utilize the peptone producing alkaline by-products. Phenol red is commonly used as a pH indicator in carbohydrate fermentation tests. Other pH indicators such as bromocresol/bromocresol purple (BCP), bromothymol/bromothymol blue (BTB), and Andrade’s can be used.
What is the function of phenol red broth Quizlet?
What is the function of phenol red broth? Phenol red broths are used to determine if a bacterium can ferment a particular sugar, and if it does ferment, if acid or acid and gas are produced. What are the differential ingredient in phenol red broth?
What is a red broth test?
Phenol Red Broth is a general-purpose differential test medium typically used to differentiate gram negative enteric bacteria.
How do you test for gas production in phenol red carbohydrate?
Fill 13 x 100 mm test tubes with 4-5 ml of phenol red carbohydrate broth. Insert a Durham tube to detect gas production. Autoclave the prepared test media (at 121°C for 15 minutes) to sterilize. The sterilization process will also drive the broth into the inverted Durham tube.