Microbial biochemistry comprises of biochemical reactions in microbial growth, various modes and mechanisms/ processes of pathogenesis required in causing infection/ diseases in the host. ... Biochemical study of microbes is crucial in the processes of their action.Biochemical tests are among the most important methods for microbial identification. Routine biochemical tests include tests for carbohydrate fermentation , methyl red , citric acid utilization , and hydrogen sulfide production 

The biochemical characteristics of a bacterium provide many traits that are useful for classification and identification. Analyzing the nutritional and metabolic capabilities of the bacterial isolate is a common approach for determining the genus and the species of the bacterium.Biochemical Activities of Bacteria: In many distinct areas of microbiology, the ability to identify microorganisms has important application. For example, in food microbiology it is important to be able to accurately identify food spoilage contaminants.

Biochemical tests that investigate the enzymatic activities of cells are powerful tests in the identification of bacteria. In the research lab, a microbiologist would be begin by examining the cell morphology, colony morphology, Gram stain reaction, and environment from which the bacterium was isolated.