Top 10 biochemical tests for identification of bacteria theory

Hassan Azam

  Biochemical testing sounds like a strange ordeal, but actually, it’s helpful. Biochemical tests are the tests used to identify bacteria differences,

All Biochemical Test


A biochemical test can help test for Gram-positive and Gram-negative bacteria. 

Gram-negative vs gram-positive bacteria

Being able to identify the type of bacteria is crucial for the host because then only can one diagnose,

  1. The thickness of the peptidoglycan layer and the presence of the outer lipid,

  1. The visual effect that the difference in how both of the walls of the bacteria are is very different,

These biochemical pathology tests are on your blood and depend on the presence,

  • catalase, 

  • oxidase, 

  • urease, 

  • gelatinase, etc.

Some of the common biochemical tests

All beings contain some characteristics about them, which is different,
Based on the reaction of a biochemical test, one can know which bacteria and what kind of bacteria they,
Doctors base their treatment and diagnosis on this test because it is that much,

Tests that measure these bacterial enzymes are easy to study, and perform and are very reliable. They can be on bacteria that have been for easy observation. Besides, these enzymes that bacteria have can let you know what all tests should be,

So here are some basic biochemical tests that are on Intracellular,

Intracellular Enzymes

As the name suggests, intracellular enzymes work. These are responsible for the growth and development of new cell membranes in bacteria. These also allow very simple substances as well as generate energy that helps in the use of these substances that help in growing.
A couple of the tests based on these enzymes include:

  • Catalase Test

These aerobic enzymes do detoxification of Hydrogen peroxide. Oxidase Test can detect the presence of this if there are oxygen bubbles present.

The test uses filter paper applied with an oxidase mix; the timely color change of this filter paper indicates a positive result.

  • Indole Test

This kind of bacteria does the formation of indole, ammonia, and pyruvic acid from tryptophan. A color change during the test determines the success of the test.   

Extracellular Enzymes

These enzymes are outside the cellular wall, opposite to what Intracellular enzymes stand for. 

These help in breaking down Macromolecules. These can spread throughout the cell membrane. Some extracellular enzyme tests include:

  • Coagulase test

Coagulase converts fibrinogen to fibrin, produced by the bacteria, which means it can turn plasma into a semi-solid state.

In the test duration, the coagulate plasma and coagulate remain undispersed; then, it would show positive test results.

  • DNase test

DNase or deoxyribonuclease is in a lot of bacteria and is capable of hydrolyzing the DNA. Thus, an agar plate containing DNA can tell whether DNase is present.

Some other tests that study extracellular enzymes include the 

  • Gelatinase test, 

  • starch hydrolysis test, 

  • and lipid hydrolysis test,

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