What is biochemical testing in microbiology?

Biochemical tests are the tests used for the identification of bacteria species based on the differences in the biochemical activities of different bacteria. Bacterial physiology differs from one type of organism to another.

What are the types of biochemical tests?

Summary of Biochemical Tests

What are the biochemical test for bacteria identification?

Each species of bacteria has specific metabolic needs and relies on different enzymes to fuel those unique needs. The presence of catalase, gelatinase, oxidase, urease, for example, can be used to identify the species of bacteria. Biochemical reactions used in biochemical tests depend on the presence of such bacteria.

What is the purpose of biochemical tests?

Microbial biochemistry tests shorten the time required to identify microbes, reduce costs, and ensure or enhance the accuracy of identification of an unknown sample. It is the fastest developing trend in microbial identification.

How do you use a biochemical test kit?

Open the kit aseptically. Peel off the sealing tape. Inoculate each well with 50 µl of the above inoculum by surface inoculation method. Alternatively the kit can be inoculated by stabbing each individual well with a loopful of inoculum.

What are the four major types of biochemical reactions?

The four major types of biochemical reactions are oxidation-reduction, hydrolysis, condensation, and neutralization.

Is Gram stain biochemical test?

This staining technique provides information about cell wall structure as Gram-positive organisms have only a grid of peptidoglycan and Gram-negative cells posses an additional lipid bilayer. … The Gram Stain remains important for identification of bacteria, and forms the basis for the selection for biochemical tests.

Is motility test a biochemical test?

Motility testing is done in conjunction with other biochemical testing using special biochemical media. … Motility Indole urease (MIU) test: It is used to determine motility, indole formation, and urease production.

How are biochemical tests used to identify Gram-negative bacteria?

Tests used to identify Gram Negative Bacteria

  1. Oxidase Test.
  2. Sugar (eg glucose) broth with Durham tubes.
  3. Methyl Red / Voges-Proskauer (MR/VP)
  4. Kliger’s Iron Agar (KIA)
  5. Nitrate Broth.
  6. Motility Agar.
  7. MacConkey agar.
  8. Simmon’s Citrate Agar.

What is catalase test in microbiology?

The catalase test is a biochemical test for aerobic organisms that detects the production of catalase enzyme in the organism. … The enzyme neutralizes the bactericidal effects of hydrogen peroxide, and its concentration in bacteria has been correlated with the pathogenicity of the organism.

What does the MR VP test determine?

This test is used to determine which fermentation pathway is used to utilize glucose. In the mixed acid fermentation pathway, glucose is fermented and produces several organic acids (lactic, acetic, succinic, and formic acids).

What does a MacConkey agar test for?

MacConkey agar is a selective and differential culture medium for bacteria. It is designed to selectively isolate Gram-negative and enteric (normally found in the intestinal tract) bacteria and differentiate them based on lactose fermentation.

How can biochemical tests useful to identify the physiological characteristics of bacteria?

A Few Biochemical/Physiological Properties Used for identification of bacteria include: nutrient utilization (carbohydrate utilization, amino acid degradation, lipid degradation), resistance to inhibitory substances (high salt, antibiotics, etc.), enzyme production (catalase, coagulase, hemolysins, etc.) and motility.

What is routine biochemical test?

Biochemical tests, which measure substances (protein, sugar, oxygen, etc.)in blood and urine, are widely used in the diagnosis of diseases and the determination of treatment. One of the measurement methods makes use of the absorbance of light, and this method is widely used in blood test equipment.

What are the disadvantages of biochemical test?

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.

What is biochemical diagnosis?

Diagnostic Clinical Biochemistry uses biochemical knowledge and techniques to assist in the diagnosis of human disease, to follow its progress and to monitor the effect of treatment. The scope of investigations varies from assessment of organ function and endocrine glands to therapeutic drug monitoring.

What is biochemical analysis?

Biochemical analysis techniques refer to a set of methods, assays, and procedures that enable scientists to analyze the substances found in living organisms and the chemical reactions underlying life processes.

Which biochemical test can be used for the rapid identification of E coli?

spot indole test coli strains that are indole positive, the spot indole test has been used for the rapid, presumptive identification of E. coli.

What is the difference between chemical and biochemical?

The key difference between chemical and biochemical reactions is that a chemical reaction is a process in which one or more reactants are converted into one or more different products regardless of the surroundings, while a biochemical reaction is the transformation of one molecule to a different molecule only inside a …

What is the first biochemical reaction?

Some argued that the beginning of biochemistry may have been the discovery of the first enzyme, diastase (today called amylase), in 1833 by Anselme Payen, while others considered Eduard Buchner’s first demonstration of a complex biochemical process alcoholic fermentation in cell-free extracts to be the birth of …

What are the different types of biochemical reactions?

Within biological systems there are six major classes of biochemical reactions that are mediated by enzymes. These include group transfer reactions, the formation/removal of carbon-carbon double bonds, isomerization reactions, ligation reactions, hydrolysis reactions, and oxidation-reduction reactions.

What is the principle of methyl red test?

In the methyl red test (MR test), the test bacteria is grown in a broth medium containing glucose. If the bacteria has the ability to utilise glucose with production of a stable acid, the colour of the methyl red changes from yellow to red, when added into the broth culture.

What bacteria is pink in color?

Serratia marcescens Bacteria A red or pink pigmented bacteria known as Serratia marcescens is thought to be the cause of the pink stuff. Serratia bacteria are common inhabitants of our environment and can be found in many places, including human and animal feces, dust, soil, and in surface waters.

What are the different tests used to differentiate Staphylococcus spp from Streptococcus spp?

Staphylococcus and Micrococcus spp. are catalase positive, whereas Streptococcus and Enterococcus spp. are catalase negative. If a Gram-positive cocci is catalase positive and presumed to be a staphylococci, the coagulase test is often performed.

What test is used for motility?

Esophageal manometry (also known as a motility test or study) is performed to see if the esophagus is contracting and relaxing properly. The esophagus is a tube that moves food from your throat to your stomach.

What is the principle of indole test?

Principle of Indole Test Tryptophanase catalyzes the deamination reaction, during which the amine (-NH2) group of the tryptophan molecule is removed. Final products of the reaction are indole, pyruvic acid, ammonium (NH4+) and energy. Pyridoxal phosphate is required as a coenzyme.

What is IMViC test?

The IMViC tests are a group of individual tests used in microbiology lab testing to identify an organism in the coliform group. … The term IMViC is an acronym for each of these tests. I is for indole test; M is for methyl red test; V is for Voges-Proskauer test, and C is for citrate test.

What test are done for gram negative bacteria?

A Gram stain is most often used to find out if you have a bacterial infection. If you do, the test will show if your infection is Gram-positive or Gram-negative.

What is difference between Gram positive and Gram negative bacteria?

Gram positive bacteria have a thick peptidoglycan layer and no outer lipid membrane whilst Gram negative bacteria have a thin peptidoglycan layer and have an outer lipid membrane.

What is the positive result for indole test?

A positive result is shown by the presence of a red or red-violet color in the surface alcohol layer of the broth. A negative result appears yellow. A variable result can also occur, showing an orange color as a result.