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.