Biochemical tests used to identify microbes To test whether bacteria contain a catalase enzyme, a microbiologist drops hydrogen peroxide into a smear of bacteria on a microscope slide. If the bacteria contain catalase, the mixture bubbles as the hydrogen peroxide decomposes into water and oxygen.

What are the biochemical test for bacteria identification?

Each species of bacteria has specific metabolic needs and relies on different enzymes to fuel those unique needs. The presence of catalase, gelatinase, oxidase, urease, for example, can be used to identify the species of bacteria. Biochemical reactions used in biochemical tests depend on the presence of such bacteria.

Why do we use biochemical tests for bacteria?

Biochemical tests are among the most important methods for microbial identification. Microbial biochemistry tests shorten the time required to identify microbes, reduce costs, and ensure or enhance the accuracy of identification of an unknown sample. It is the fastest developing trend in microbial identification.

What is biochemical reaction of bacteria?

Biochemical reactions are very important in the identification of bacterial isolates and in the identification of different bacterial species. These tests depend on the presence of certain enzymes, such as catalase, oxidase, urease, gelatinase, etc., produced by the bacteria.

What do you mean by biochemical test?

The biochemical profile is a series of blood tests used to evaluate the functional capacity of several critical organs and systems, such as the liver and kidneys. These tests can be done on an empty stomach or not, and are usually accompanied by a complete blood count (CBC).

How do biochemical test help identify an unknown bacterial species?

Biochemical tests help identify an unknown bacterial species because they determine certain characteristics of the bacteria in question that make it possible to determine the species. Given what you know about genetics and molecular biology, describe another way you might be able to identify specific bacteria.

What is the positive result for indole test?

A positive result is shown by the presence of a red or red-violet color in the surface alcohol layer of the broth. A negative result appears yellow. A variable result can also occur, showing an orange color as a result.

How do you perform a biochemistry test?

Test Procedure

1. Dilute your organism in a tube of sterile water to obtain a turbidity equivalent to the 0.5 McFarland test standard.
2. Using a sterile 1mL pipette, place 1 mL of organism into the middle of the tube.
3. Cap tightly; do not jostle.
4. Incubate for 24 hours at 37°C.

Which biochemical test can be used for the rapid identification of E coli?

coli strains that are indole positive, the spot indole test has been used for the rapid, presumptive identification of E. coli.

How do you identify a Gram positive bacteria?

Under a microscope, gram-positive bacteria appear purple-blue because their thick peptidoglycan membrane can hold the dye. The bacteria is called gram-positive due to the positive result. Gram-negative bacteria stain pink-red. Their peptidoglycan layer is thinner, so it doesn’t retain the blue color.

What is biochemical reaction?

A biochemical reaction is the transformation of one molecule to a different molecule inside a cell. Biochemical reactions are mediated by enzymes, which are biological catalysts that can alter the rate and specificity of chemical reactions inside cells.

What are biochemical characteristics of bacteria?

A Few Biochemical/Physiological Properties Used for identification of bacteria include: nutrient utilization (carbohydrate utilization, amino acid degradation, lipid degradation), resistance to inhibitory substances (high salt, antibiotics, etc.), enzyme production (catalase, coagulase, hemolysins, etc.) and motility.

What are biochemical tests examples?

Summary of Biochemical Tests

• Catalase Test.
• Mannitol Salt Agar (MSA)
• Blood Agar Plates (BAP) Streak-stab technique.
• Taxos P (optochin sensitivity testing)
• Taxos A (bacitracin sensitivity testing)
• CAMP Test.
• Bile Esculin Agar.
• Nitrate Broth.