MacConkey agar media was first introduced by a scientist named Alfred Theodore MacConkey in the year 1890s. It is primarily exercised to isolate and differentiate the non-fastidious, gram-negative bacilli belonging to the Enterobacteriaceae family. Previously, it was first considered as “Solid differential media”. But now, both liquid broth and solid culture MacConkey media preparations are …
Pinocytosis is a kind of endocytic process. It refers to the cellular mechanism where the bilayer cell membrane invaginates to form a sac to uptake the extracellular fluids and solutes into the cytoplasm. Pinocytosis is a spontaneous endocytic process, which occurs in almost all cells. It prevalently occurs in eukaryotes. Pinocytosis, cell drinking or fluid-phase …
Phagocytosis is a method of endocytosis. It refers to the cellular mechanism where the invagination of the plasma membrane causes internalization of the extracellular contents into the cell in the form of vesicles. Internalization is a process where a plasma membrane undergoes successive invagination to form membrane-bound vesicles, which later detach from the cell membrane …
Exocytosis is a means of membrane transportation that expels the intracellular material out of the cell. The transport of the substance is mediated by the vesicles that eliminate the cell debris and release specific proteins, enzymes, hormones etc., outside the cell. It is a type of active transport mechanism that makes the use of ATP. …
The difference between the cell wall and the cell membrane is primarily due to the differences in three factors like composition, function and permeability. The cell wall composition mainly comprises proteins and carbohydrates, whereas a cell or plasma membrane comprises lipids, proteins, and some amount of carbohydrate. The functional role of the cell wall is to …
A motility test refers to the biochemical or microscopic examination of an organism that checks the existence of cellular motility. By performing this test, we could differentiate the two major groups of bacteria, namely motile and non-motile, based on their cellular movement. Few organisms are motile, and some are non-motile. Still, all living organisms tend …
Vermicomposting is a composting technique, which turns the organic debris into a humus-like product by employing earthworms. “Vermicompost” is the compost produced by the vermicomposting unit. The vermicompost merely refers to the earthworm’s excrement, which provides essential nutrients, aeration, porosity, structure, fertility and water-holding capacity to the soil and plant body. The vermicomposting method requires …
The bile solubility test is a biochemical test that distinguishes bile soluble and bile resistant α-haemolytic Streptococci. Streptococcus pneumoniae is the only strain that emulsifies by reacting with the bile solubility reagent, whereas the other α-haemolytic Streptococci do not undergo such reaction. The reason for the dissolution of the Streptococcus pneumoniae is due to the …
Urease test is an analytical method practised to identify the urease positive and negative organisms based on the production of cytosolic urease enzyme. It distinguishes the Proteus species from the non-lactose fermenting members belonging to the Enterobacteriaceae family. Urease test makes the use of urea base. Conventionally, Stuart formulated urea broth was used to identify …
The coagulase test is an analytical method that demarcates the staphylococci species into coagulase-positive and coagulase-negative species. Coagulase is an enzyme, which can either bound to the cell surface of bacteria as “Bound coagulase” or reside within the extracellular space as “Free coagulase”. Staphylococcus aureus, S. intermedius, S. hyicus are coagulase-positive organisms. Staphylococcus epidermis, S. saprophyticus, …