Microbiology Quiz 7
IMVIC
-Indole -Methyl Red -Voges-Proskauer Test -Citrate
5-7 Citrate Test
1. Simmon's Citrate Agar Slant 2. Citrate 3. Citrate permease 4. Utilization of Citrate 5. Ammonia (NH3) and Ammonia hydroxide (NH4OH) *6. Bromothymol Blue Blue: Alkaline Green: Neutral 7. growth and blue colored agar indicates (+) test and citrate is utilized.
5-10 Starch Hydrolysis Test
1. Starch Agar 2. Starch---> (carbohydrate)<--- polymer glucose (sugar) *3. Alpha-amylase--> breaks glycosidic bonds Alpha 1,4 *4. Hydrolysis 5. Glucose *6. Gram's Iodine--> reacts with starch = blue dark halo 7. clearing around growth indicates (+) test and amylase is present.
Phosphate buffer
Prevents false positives
Buffer
Used to maintain the pH.
Fermentation
produces acid and sometimes gas
What limits the diffusion of O2 in the medium?
0.1% Agar
3. Answer the following questions regarding the Phenylethyl Alcohol Agar plate. a. What is the selective ingredient(s) in this media?
0.25% Phenyethyl Alcohol
5-14 Gelatin Hydrolysis Test
1. Gelatin Broth 2. Gelatin --> Protein 3. Gelatinase *4. Hydroysis 5. Soluble Amino Acids 6. No reagents 7. Liquid indicates (+) test and gelatinase is present.
Enterobacteriaceae Family
1. Gram-negative 2. Bacillus 3. Non-spore forming 4. Glucose fermenters 5. Nitrate reducers 6. Oxidase (-)
5-3 MR and VP Test
1. MR-VP Broth 2. Glucose***-Peptones-phospahte buffer 3. Varies 4. Fermentation 5. -MR with produce strong acids -VP produces intermediates (acetoin) & 2,3 butanediol 6. Methyl Red -Red : 4.4, Yellow: 6.4, Orange: 4.5-6.3 Voges-Proskauer -Reagent A: alpha naphthol -Reagent B: KOH
5-13 Casein Hydrolysis Test
1. Milk Agar Plate *2. Casein--> Protein found in milk *3. Caseinase or (casease) *4. Hydrolysis 5. Soluble amino acids *6. No reagents. 7. Clearing around the growth indicates (+) test and casease is present and hydrolysis can happen.
Biochemical Test
1. Name of the media 2. Substrate 3. Name of Enzyme 4. Biochemical Reaction 5. End product 6. Indicator or Reagents 7. Observations, Results, and Conclusion.
Sulfur reduction
1. SIM media 2. Sodium thiosulfate 3. Sodium thiosulfate reductase 4. Reduction 5. Hydrogen sulfide (H2S) 6. ferrous ammonium citrate reacts with water and produces ferric sulfide a black precipitate (FeS).
Indole Production
1. SIM media 2. Tryptophan (Indole group) *3. Tryptophanase 4. Hydrolysis 5. Indole 6. Kovak's Reagent reacts with Indole and produces a red color.
5-6 Nitrate Reduction
1. Tryptic Nitrate Broth 2. KNO3 (potassium nitrate) 3. Nitrate Reductase (simple) Strong Nitrate reducing enzyme (long) 4. Reduction (simple) Denitrification (long) 5. Nitrate (NO2) (Simple) N2 gas or non-gaseous nitrogenous compounds. *6. Reagent A: Alpha Naphthylamine Reagent B: sulfanilic acid zinc ---> reducer of NO3
5-15 Urea Hydrolysis Test
1. Urea Slant 2. Urea 3. Urease *4. Hydrolysis 5. NH3 or NH4 6. Phenol Red (indicator)
How much time has to pass to call the result negative?
72 hours.
1. Answer the following questions regarding the starch hydrolysis test. a. What is the enzyme that is necessary for starch hydrolysis to take place?
Alpha amylase
What happens when you don't incubate long enough?
False negative results.
Triple Sugar Iron Agar Test
Carbohydrate fermentation 1. TSI slant *2. 0.1 % Glucose and 1% Lactose and Sucrose 3. Varies 4. Fermentation 5. Acid and Gas 6. Phenol Red
5-7 Citrate test what is the purpose?
Does the organism have the ability of use citrate as their sole carbon source and perform citrate fermentation.
What is the solidifying component for the broth?
Gelatin
b. What reagent is used to test for starch hydrolysis?
Gram's Iodine
Motility
Growth radiating from the stab line then it is positive.
c. What type of organism does this media select against?
Inhibit gram (-)
What is the purpose of 5-15 Urea Hydrolysis?
It is used to differentiate organisms based on their ability to hydrolyze urea with the enzyme urease.
Kligler Iron Agar experiment
Sulfur reduction 1. TSI slant 2. Sodium thiosulfate 3. Sodium thiosulfate reductase 4. Reduction 5. H2S- turns media black 6. Ferrous ammonium citrate
What is the purpose of EX 5-19 Triple Sugar Iron Agar and Kligler Iron Agar experiment?
TSIA and KIA are primarily used to differentiate members of Enterobacteriaceae and distinguish them from other gram-negative rods such as P. aeruginosa. -Checks for carbohydrate fermentation and sulfur reduction.
5-6 Nitrate Reduction goal?
The purpose is to reduce nitrate to specific nitrogenous products.
What is the purpose of EX 5-3?
The purpose is to see if mixed acid fermentation the reason for seeing if the bacteria can perform this.
5-18 SIM Test
The purpose of this test is for determination of 3 bacterial activities: sulfur reduction, indole production from tryptophan, and motility.
5-13 Casein Hydrolysis the purpose?
To determine the presence of casease that some bacteria can produce.
5-14 Gelatin Hydrolysis purpose?
To see if there is a presence of gelatinase which can be detected using nutrient agar.
5-10 Starch Hydrolysis determines
We are testing if organisms can produce alpha amylase, beta amylase, and or to see if alpha 1,6-glucosidase is present (or more simply amylase is present)