Methyl red test differentiates whether a test organism can undergo mixed acid fermentation or not by allocating adequate glucose. Organisms that can ferment glucose will give a positive MR test by producing a large amount of acid, while some organisms give a negative MR test. MR-test also helps to identifying and categorizing the different genera of …
The citrate utilization test distinguishes different genera of enteric group based on the property of citrate utilization through an enzyme catalyst (Citrase). Test organisms form many by-products by the time they utilize citrate incorporated in the test media. By the complete hydrolysis of citrate, an alkaline product (sodium carbonate) forms that cause alkalinity in the …
Indole test is a biochemical test determining and classifying the bacteria based on their tendency to decompose amino acid (Tryptophan) into a heterocyclic organic compound (Indole). It is a part of a biochemical method popularly known as the IMViC test, in which ‘I’ stands for the indole test. Indole is one of the end products …
Bacterial conjugation is a gene transfer mechanism introduced by the scientists named Lederberg and Tatum in 1946. The conjugation method was first studied in Escherichia coli. The formation of a conjugation tube is the characteristic feature of a conjugation mechanism. Besides transduction and transformation mechanisms, some bacteria passes the genetic information from a donor to …
SOS repair or “bypass” or “Emergency” repair is one of the DNA repair mechanisms introduced in 1975 by a scientist named Miroslav Radman. SOS repair primarily recovers the DNA damage caused due to environmental stresses. It serves as a regulatory system, which comprises many complex inducer proteins that repair the damaged DNA. SOS system also …
Oxidation pond or lagoon or water stabilization pond is a secondary wastewater treatment that treats waste or sewage coming from industries, residential areas, etc. It uses microorganisms like bacteria, algae and light energy (sunlight) to stabilize the wastewater. The oxidation pond is constructed 1-1.5 m deep inside the soil and provided with inlet and outlet systems. …
Chromomycosis, or Chronic subcutaneous mycosis, is a severe fungal infectious disease that infects the skin’s subcutaneous tissue. A diverse group of dematiaceous or black fungi cause chromomycosis. Dematiaceous fungi are the heterogeneous fungal group, which usually form lesions or abscess in the subcutaneous tissue. Interaction of host tissue with the fungus shows a non-specific kind …
DNA mismatch repair is a mechanism of repairing DNA by the removal of mismatched nucleotides via MMR proteins. The role of mismatch repair proteins in the prokaryotic DNA helped to study the mismatch repair system in the eukaryotic DNA as well. The mismatch repair system is essential, as it maintains the genome’s stability at the time …
The electron transport system refers to the “Electron transport chain” or “ETS” (in abbreviated form) that is present in the inner mitochondrial membrane. ETS involves electron transfer through a series of protein complexes from higher (NADH+) to lower energy state (O2) by releasing protons into the cytosol. A movement of proton or H+ from a …
Clostridium botulinum is a clinically significant bacteria, which causes a sporadic but severe disease called “Botulism”. It produces a particular type of exotoxin that affects the nervous system by inhibiting the neuromuscular junction’s activity. Therefore, the botulinum toxin behaves as a neurotoxin, which blocks the release of a neurotransmitter (acetylcholine). Acetylcholine is a chemical compound …