Coliforms are all facultative and aerobic rod-shaped, gram-negative, non-spore-forming bacteria that produce lactose by fermentation with gas and acid production within 48 hours, at temperatures of 35 degrees Celsius. Methods to identify, enumerate and presumedly identify coliforms are utilized in the testing of dairy and food products. One method of performing the presumptive test to identify coliforms employs the Violet Red Bile Agar (VRBA). The Violet Red Bile Aggar (VRBA) is an selec-tive medium that can be used to detect and quantify lactose-fermenting coliform microorganisms.
Tryptic Soy Agar can be used to grow microorganisms. These media are non-selective and general-purpose. They provide enough nutrients to support a variety of microorganisms. This medium can also be used to grow, store, maintain, and transport pure microorganism cultures.
Baird Parker Agar was created by Baird Parker using the Tellurite–glycine formulation of Zebovitz et al. It allows for a good differentiation between coagulase positive strains.
Yeasts, unicellular eukaryotes, are a well-studied model organism in molecular genomics. They are chemoorganotrophs because they use organic compounds for energy. Yeast extract peptone, or YEPD), Growth Agar is used to maintain and propagate yeasts. YPD is a complete medium that allows for yeast growth.
Eosin Methylene Blue (EMB), a microbiological media, is a differentiating medium that slightly inhibits the growth and color of Gram-positive bacteria. It also provides a color indicator to distinguish between organisms that ferment lactose (e.g. E.coli) and those who do not (e.g. Salmonella, Shigella). Holt-Harris, Teague, and Levine first created EMB agar.
For the cultivation of Haemophilus, Levinthal’s Medium can be used. Although there are many species in the genus Haemophilus that can cause infections, they all share a common morphology. They also require blood-derived factors for growth. This is what gave the genus its name. The Haemophilus Genus is a large grouping of gram-negative rods, which can grow on agar-containing human blood. Two factors are required for Haemophilus species to grow: factor-X, and factor-V.
Lysine iron Agar (LIA), a differential medium, is used to test organisms’ ability to deaminate or decarboxylate Lysine. Lysine deamination, an aerobic process, occurs in the media. Lysine decarboxylation, an anaerobic process occurring in the media’s butt, is also known as Lysine decarboxylation. Edwards and Fife created LIA in 1961 in order to presumptively determine Salmonella species. This includes Salmonella arizonae that is lactose fermenting, which has been linked to foodborne gastroenteritis outbreaks.
The majority of bacteria are able to ferment carbohydrates, especially sugars. Within them, every bacteria is able to ferment just a few of the sugars, whereas it is unable to ferment all the other sugars. So, the sugars that a bacterium is able to ferment, as well as the sugars that it can’t, is the signature of the bacterium and is an important factor in its determination. It is the Triple Sugar Iron (TSI) Agar is a type of culture medium known for its capacity to determine a microorganism’s capacity to produce sugars and generate hydrogen sulfur.
Selenite Broth was invented by Leifson who proved that selenite is inhibitory to bacteria, coliforms, and other species, like streptococci from feces, which are found in fecal samples and, consequently, beneficial in the recuperation from Salmonella species. Selenite-F Broth is utilized to enrich the environment that is buffered by Lactose Peptone Broth to which Sodium Biselenite is added to act as the agent that is selective for elimination of Salmonella from urine, feces and water, as well as food items and other substances that are of sanitary significance.
In 1984, Bolton et al. Bolton et al. (1984) suggested that charcoal could be used to replace blood in a medium for the isolation of Campylobacter species. Endtz et al. Later, it was confirmed that Campylobacter isolates at a higher rate when using charcoal selective media.
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