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 Clostridium tetani

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Biochemical Test of Clostridium tetani

Some of the characteristics are as follows: Basic Characteristics Properties (Clostridium tetani) Capsule Negative (-ve) Catalase Negative (-ve) Flagella Peritrichous Gas Positive (+ve) Gelatin Hydrolysis Positive (+ve) Gram Staining Gram-stain-positive, … Read more

Biochemical Test of Chlamydia trachomatis

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Biochemical Test of Chlamydia trachomatis

Some of the characteristics are: Basic Characteristics Properties (Chlamydia trachomatis) Organism Type Obligate intracellular organism that parasitize and multiply in the cytoplasm of eukaryotic cells within membrane bound vacuoles, termed … Read more

Biochemical Test of Enterococcus faecium

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Biochemical Test of Enterococcus faecium

Some of the characteristics are as follows: Basic Characteristics Properties (Enterococcus faecium) 40% Bile Salts Positive (+ve) Capsule Negative (-ve) Catalase Negative (-ve) Citrate Negative (-ve) Gelatin Hydrolysis Negative (-ve) … Read more

Biochemical Test of Serratia marcescens

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Biochemical Test of Serratia marcescens

Biochemical Test of Serratia marcescens ­Basic Characteristics Properties (Serratia marcescens) Capsule Negative (-ve) Catalase Positive (+ve) Citrate Positive (+ve) Flagella Positive (+ve) Gas Variable Gelatin Hydrolysis Positive (+ve) Gram Staining … Read more

Biochemical Test of Enterococcus faecalis

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Biochemical Test of Enterococcus faecalis

Basic Characteristics Properties (Enterococcus faecalis ) Bile Resistance Resistance to 40% (v/v) bile Capsule Negative (-ve) Catalase Negative (-ve) Citrate Negative (-ve) Flagella Negative (-ve) Gelatin Hydrolysis Variable Gram Staining … Read more

Biochemical Test of Clostridium difficile

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Biochemical Test of Clostridium difficile

Biochemical Test of Clostridium difficile ­Basic Characteristics Properties (Clostridium difficile) Capsule Capsulated Catalase Negative (-ve) Flagella Flagellated Gelatin Hydrolysis Positive (+ve) Gram Staining Positive (+ve) H2S Positive (+ve) Hemolysis Negative … Read more

Biochemical Test of Vibrio cholerae

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Biochemical Test of Vibrio cholerae

Image Source: Belén García, dibujandoafrica.com ­Basic Characteristics Properties (Vibrio cholerae) Capsule Non-Capsulated Citrate +ve Flagella Flagellated Gas -ve Gelatin Hydrolysis +ve Gram Staining -ve H2S -ve Hemolysis Beta Hemolysis Indole … Read more