1. Principle, Reagents & Media
Procedures & End results
BIOCHEMICAL ACTIVITIES

3. BIOCHEMICAL ACTIVITIES OF BACTERIA:
Biochemical properties could be used as tools
of identification  demonstrate certain
metabolic activity of microbes
Example : Fermentation – durham tubes
 Carbohydrates, amino acids, organic
acids
 1. gases – Carbone dioxide, methane, hydrogen
 2. Acid production – use of indicators to detect
 Either acid or gas or both can be collected

4. IMVIC - INDOLE TEST
 Principle : product of hydrolysis of an amino acid
tryptophan
 Media – SIM (Sulfide Indole Motility)
 Reagent - (Ehrlich’s) Para-dimethyl-
aminobenzaldehyde
 Positive result :(+) pink or red color
 Negative Result : (-) absence of pink or red color

5. IMVIC - METHYL RED TEST
 Methyl red is a pH indicator
 Principle : production of sufficient acidity from
glucose
 Media- MR-VP broth
 (+) red - acid
 (-) yellow - alkaline

6. IMVIC - VOGUES PROSKAUER
• production of acetyl-methyl carbinol
from glucose
•media: MR-VP broth
•reagent: 40% KOH
•Positive (+) result = production of
an eosin like color

7. IMVIC - CITRATE UTILIZATION TEST
 Principle: utilizes citrate as a source of Carbon
 Media :Simmon Citrate (SCA)
 (+) blue color
 (--) green color

8. OTHER COMMON BIOCHEMICAL TESTS:
 Coagulase test
 Catalase test
 Urease test
 Hemolysis test
 Greig’s Test
 Oxidase Test
 Hydrogen Sulfide Test

9. ASSIGNMENT:
 Find the other biochemical Tests & tabulate
them based on:
 Working principle
 Reagents & Media
 Positive & Negative Results

10. WHAT TO DO?
 Place all your glassware in a plastic bag
 Autoclave 15 psi, 121 C, 15 minutes
 Wash , clean and dry
 Wrap and sterilize in the oven, 150 C, 45
minutes

11. MEDIA PREPARATION
 Prepare 200 ml each ( for the whole class)
 SIM
 MRVP
 SCA
 Dispense into 4 test tubes
1 tube SIM
 2 tubes MRVP
 1 tube SCA ( Slant )

12.  Inoculate with bacteria ( get from me )
 Incubate in incubator 48 hours
 Add the reagents ( from previous slides )
 Check results
 Make a one page write – up
 Submit