Biochemical Test

Biochemical tests are laboratory procedures that use specific chemical reactions to identify and characterize microorganisms, such as bacteria. These tests are often used to identify the presence of specific enzymes or metabolic pathways in a microorganism, which can help to distinguish it from other microorganisms.

Some common biochemical tests used in bacteriology include:

Oxidase test: This test is used to detect the presence of the enzyme cytochrome oxidase, which is involved in the metabolism of oxygen.
Catalase test: This test is used to detect the presence of the enzyme catalase, which helps to break down hydrogen peroxide.
Indole test: This test is used to detect the presence of the enzyme tryptophanase, which breaks down the amino acid tryptophan.
Nitrate reduction test: This test is used to detect the ability of a microorganism to reduce nitrate to nitrite.
Gelatinase test: This test is used to detect the ability of a microorganism to produce the enzyme gelatinase, which breaks down gelatin.

These are just a few examples of the many different biochemical tests that are used in bacteriology. Biochemical tests can be useful for identifying and classifying bacteria, and for understanding their metabolism and ecological role.

Voges Proskauer (VP) Test – Principle, Procedure, Results

Published on: May 13, 2024 by BNO Team

In 1898, Voges as well as Proskauer (16)characterized the process of fermentation of sugars by a variety of bacteria. They demonstrated that the gas that was produced during the process was a mixture of H2 and CO2 that when they added KOH to the cultures been grown in glucose peptone medium to allow for a prolonged period of incubation in presence of oxygen certain organisms developed a red fluorescent color. While the exact nature of the color was not known in the early days, this technique was suggested to differentiate between the bacterial strains that produced it and ones that didn’t. in 1906 Arthur Harden analyzed the fermentation products of Enterobacter aerogenes. He discovered that when it was surrounded by glucose, the organism made two compounds, acetoin as well as 2,3-butanedio.

Spot Indole Test – Principle, Procedure, Result, Uses

Published on: May 13, 2024 by BNO Team

What is Spot Indole Test? Definition of Spot Indole Test The Spot Indole Test is a rapid biochemical method used to detect the production of indole by bacteria, indicating their ability to metabolize the amino acid tryptophan. This test aids in differentiating specific bacterial species based on their tryptophan degradation capabilities. Objectives of Spot Indole Test … Read more

Indole Test – Principle, Procedure, Result, Uses

Published on: May 13, 2024 by BNO Team

What is Indole test? Indole Test Definition The indole test is a biochemical assay used to determine a bacterium’s ability to metabolize tryptophan into indole through the action of the enzyme tryptophanase, aiding in the differentiation and identification of certain bacterial species. Purpose of Indol Test (Objectives of Indole Test) The indole test serves a … Read more

Hippurate Hydrolysis Test – Principle, Procedure, Result

Published on: May 13, 2024 by BNO Team

Purpose of Hippurate Hydrolysis Test Principle of Hippurate Hydrolysis Test Hippurate → Glycine + Benzoic acid Glycine + Ninhydrin → purple-colored complex Composition of Hippurate Hydrolysis Broth Ingredients Gms / Litre HI powder# 10.000 Peptone 10.000 Sodium chloride 5.000 Sodium hippurate 10.000 Final pH ( at 25°C) 7.4±0.2 Equivalent to Heart infusion powder Preparation of … Read more

Fructose Metabolism Pathway – Fructolysis

Published on: May 13, 2024 by BNO Team

Location of Fructolysis Why does fructose metabolism or fructolysis occur in liver cells? Properties and Sources of Fructose Absorption of Fructose From Fructose to Fat/Fructolysis/fructose metabolism pathway Steps of fructose metabolism pathway 1. Step 1 2. Step 2 3. Step 3A Metabolic Pathway Notes: At this point, the liver cell can use the same steps … Read more

Coliforms Presence/Absence (PA) Test

Published on: May 13, 2024 by BNO Team

What is Presence/Absence Test? Principle of Presence/Absence Test Objective of Presence/Absence Test PA Broth Preparation Composition Ingredients Gms / Litre Peptic digest of animal tissue 5.000 Tryptose 9.830 Beef extract 3.000 Lactose 7.460 Sodium chloride 2.460 Dipotassium phosphate 1.350 Monopotassium phosphate 1.350 Sodium lauryl sulphate 0.050 Bromo cresol purple 0.0085 Final pH ( at 25°C) … Read more

BOD Test – Biological Oxygen Demand Test

Published on: May 13, 2024 by BNO Team

Objectives of BOD Test Principle of BOD Test Under alkaline circumstances (by adding Alkaline-iodide-azide), manganese sulphate precipitates manganese hydroxide as a white precipitate. This combines with the sample’s dissolved oxygen to generate a brown precipitation. On an acidic environment, manganese changes to its divalent form and releases iodine. This released iodine is titrated using starch … Read more

COD Test – Test for Chemical Oxygen Demand In Wastewater

Published on: May 13, 2024 by BNO Team

After wastewater treatment, the chemical oxygen demand (COD) is used to determine the amount of contamination in the water. The higher value of chemical oxygen demand implies that the water sample has a greater amount of organic pollutants. The COD test measures only substances that can be chemically digested. The determination of COD requires less … Read more

Glucose Tolerance Test – Principle, Procedure, Types, Applications

Published on: May 13, 2024 by BNO Team

What is a Glucose Tolerance Test? A glucose tolerance test is a test that is used to diagnose diabetes or prediabetes. It involves measuring the body’s ability to process glucose, a type of sugar that is the main source of energy for the body. During the test, a person will drink a solution containing a … Read more

Bacteriological Examination of Waters by Using Membrane Filtration Method

Published on: May 13, 2024 by BNO Team

Human pathogenic bacteria transmitted via the fecal-oral route, i.e., primarily intestinal pathogens, constitute one component of drinkable water quality analysis. Screening water for faecal contamination by testing for the presence of an indicator microbe is more practicable than doing thorough routine examinations for the presence of every type of disease. If you want to know … Read more