Biochemical Tests

Biochemical tests are the tests that are performed on different bacteria for their identification based on their biochemical activities towards different biochemical compounds. Biochemical tests are one of the traditional methods for the identification of microorganisms, generally performed with phenotypic identification. For many years, these methods were widely used and continue to be used today, especially in some laboratory routines where a particular type of microorganism must be quickly identified. The ability of microorganisms to utilize certain biomolecules, resulting in useful organic compounds on their own, forms the basis of various biochemical tests. Biochemical tests are of different types, where the identification or distinction between different microorganisms is carried out 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 due to increased turbidity in the liquid medium. In other tests, however, the results are based on the color change of the medium as a result of the change in pH of the medium. Microorganisms can be classified into different groups based on their reaction to such tests. Some tests even allow the distinction of microorganisms at the species level. Biochemical tests are therefore essential as they are inexpensive and relatively simple to perform. The physiology of bacteria and other microorganisms differ from each other, which allows the differentiation of these microorganisms. However, biochemical tests have some drawbacks. Despite being inexpensive and allowing both quantitative and qualitative information on the diversity of microorganisms present in a sample, these methods are laborious and time-consuming and results are only seen after several days. In some cases, false positives are obtained, especially when considering similar microbial species.