Biochemical Test

Biochemical tests are the tests that are performed on different bacteria for their identification on the basis of their biochemical activities towards different biochemical compounds.

Biochemical tests are one of the traditional methods for the identification of microorganisms, usually performed with phenotypic identification.
For many years these methods were employed extensively, and they continue to be used nowadays, especially in some laboratory routines where a particular type of microorganism has to be identified rapidly.
The ability of microorganisms to utilize certain biomolecules, resulting in useful organic compounds for themselves forms the basis of various biochemical tests.
Biochemical tests are of different types, where the identification or distinction between different microorganisms is made on various bases.
One of the traditional methods commonly used is a simple visual detection of the growth of the organism in the presence of essential nutrients by increased turbidity in the liquid medium.
In other tests, however, the results are based on the change in color of the medium as a result of the change in the pH of the medium.
Microorganisms can be classified into different groups on the basis of their reaction to such tests. Some tests even allow the distinction of microorganisms to the species level.
Biochemical tests are thus, essential as they are inexpensive and relatively simple to perform.
The physiology of bacteria and other microorganisms differs from one another, which allows for the differentiation of such microorganisms.
Biochemical tests, however, have some disadvantages. Despite being inexpensive and allowing both quantitative and qualitative information about the diversity of microorganisms present in a sample, these methods are laborious and time-consuming, and results are only observed after several days.
In some cases, false positives are obtained, especially when considering similar microbial species.

Biochemical Test of Kingella kingae

September 5, 2022May 30, 2022 by Sagar Aryal, PhD

Some of the characteristics are as follows: Basic Characteristics Properties (Kingella kingae) 10% Bile Negative (-ve) Capsule Positive (+ve) Catalase Negative (-ve) Citrate Negative (-ve) Coagulase Negative (-ve) Gas Negative … Read more

Biochemical Test of Campylobacter jejuni

September 5, 2022May 28, 2022 by Sagar Aryal, PhD

Biochemical Test of Campylobacter jejuni Basic Characteristics Properties (Campylobacter jejuni) Capsule Capsulated Catalase Positive (+ve) Flagella Flagellated Gram Staining Negative (-ve) Growth at 25°C Negative (-ve) Growth at 37°C Positive … Read more

Biochemical Test of Bordetella pertussis

September 5, 2022May 26, 2022 by Sagar Aryal, PhD

Some of the characteristics are as follows: Basic Characteristics Properties (Bordetella pertussis) Capsule Positive (+ve) Catalase Positive (+ve) Citrate Negative (-ve) Flagella Negative (-ve) Gelatin Hydrolysis Negative (-ve) Gram Staining … Read more

Biochemical Test of Mycobacterium tuberculosis

September 5, 2022May 25, 2022 by Sagar Aryal, PhD

Biochemical Test of Mycobacterium tuberculosis Basic Characteristics Properties (Mycobacterium tuberculosis) 5 % NaCl Tolerance Negative (-ve) 68°C Catalase Test Negative (-ve) Acid Fast Stain Positive (+ve) Acid Phosphatase Negative (-ve) … Read more

Biochemical Test of Corynebacterium diphtheriae

September 5, 2022May 24, 2022 by Sagar Aryal, PhD

Biochemical Test of Corynebacterium diphtheriae Basic Characteristics Properties (Corynebacterium diphtheriae) CAMP Negative (-ve) Capsule Non-Capsulated Catalase Positive (+ve) Cetrimide Test Negative (-ve) Citrate Negative (-ve) Coagulase Negative (-ve) Flagella Non-Flagellated … Read more

Biochemical Test of Pseudomonas aeruginosa

November 12, 2023May 23, 2022 by Sagar Aryal, PhD

Biochemical Test of Pseudomonas aeruginosa Basic Characteristics Properties (Pseudomonas aeruginosa) Capsule Some Non-Capsulated and Some are encapsulated (Pseudomonas aeruginosa secretes a capsule-like polysaccharide called alginate- Sumita Jain and Dennis E. … Read more

Biochemical Test of Haemophilus aegyptius

January 13, 2023May 17, 2022 by Sagar Aryal, PhD

Some of the characteristics are as follows: Basic Characteristics Properties (Haemophilus aegyptius) Capsule Negative (-ve) Catalase Positive (+ve) Gas Negative (-ve) Gram Staining .Gram-negative H2S Negative (-ve) Hemolysis Negative (-ve) … Read more

Biochemical Test of Lactobacillus spp.

March 12, 2024May 15, 2022 by Sagar Aryal, PhD

Some of the characteristics are as follows: Basic Characteristics Properties (Lactobacillus spp.) Capsule Negative (-ve) Catalase Negative (-ve) Citrate Negative (-ve) Flagella If present, peritrichous Gas Negative (-ve) Gelatin Hydrolysis … Read more

Biochemical Test of Haemophilus parainfluenzae

September 5, 2022May 15, 2022 by Sagar Aryal, PhD

Some of the characteristics are as follows: Basic Characteristics Properties (Haemophilus parainfluenzae) Capsule Variable Catalase Variable Gas Variable Gram Staining Gram-negative (-ve) H2S Positive (+ve) Hemolysis Negative (-ve) Indole Variable … Read more

Biochemical Test of Haemophilus influenzae

January 13, 2023May 5, 2022 by Sagar Aryal, PhD

Image Source: Manitoba Health and Fine Art America. Some of the characteristics are as follows: Basic Characteristics Properties (Haemophilus influenzae) Capsule Strain-dependent Catalase Positive (+ve) Flagella Negative (-ve) Gas Negative … Read more