General Purpose Media
Media that provides enough nutrients in which most any microorganism will utilize for growth. Allows for a wide variety of microorganisms to grow (typically agar plus nutrients)
Ex: Soy Agar
TSA
Enriched Media
has added growth factors may be added individually or in complex mixtures. May be chemically defined or chemically undefined, simple or complex.
Ex: Blood Agar
Selective Media
Used for the growth of only select microorganisms. Will inhibit growth of some organisms while encouraging the growth of others.
Ex: MacConkey's Agar
Differential Media
Allows one to distinguish between or among different microorganisms based on a difference in colony appearance (color, shape, or growth pattern) on the medium.
dyes in the medium (e.g.: eosin/methylene blue in EMB) or pH indicators change the color of the
Selective and Differential Media
Allows the growth of certain organisms while inhibiting the growth of others while allowing different genera to be differentiated
i.e., E.coli can be visually Differentiated from Salmonella on EMB or Mac
Enrichment Media
Media used to isolate a bacterium by enhancing growth due to added nutrients. Designed for the growth of fastidious bacteria. Rarely contains certain inhibitory substance to prevent the growth of normal competitors.
EX
GN (Gm neg) broth or Selenite F brot
Tryptic Soy Agar (TSA)
general purpose medium used for the isolation of wide variety of bacteria. Contains tryptone, soy (source of B vitamins and amino acids)
Nutrient Agar (NA)
general purpose medium used for the isolation of wide variety of bacteria.
Blood Agar Plate (BAP)
enriched with blood to enhance the growth of fastidious bacteria usually pathogenic. Groups of bacteria determined by hemolysis of red blood cells by bacterium. Alpha (a) hemolysis - bacterium partially hemolyses RBC's with a partial clearing zone around
MacConkey's Agar (MAC)
selects and differentiates members of Enterobacteriaciae. Differentiates genera Salmonella & Shigella from other Enterobacteriaciae. Contains bile salts and crystal violet that inhibits growth of gram positive bacteria. Differentiates non coliforms from c
Triple Sugar Iron Agar (TSI)
characterizes members of Enterobacteriaciae on basis of glucose, sucrose, & lactose fermentation, gas production, and hydrogen sulfide production. Contains pH indicator phenol red which changes from red to yellow color if fermentation occurs. Gas producti
Eosin Methylene Blue Agar (EMB)
selects and differentiates members of Enterobacteriaciae. Differentiates genera of coliform group from other genera of Enterobacteriaciae on basis of lactose fermentation. Methylene blue in agar inhibits growth of gram positive bacteria. Lactose fermentor
Mannitol Salt Agar (MSA)
selects and differentiates among members of genus Staphylococcus. Selective for gram positive staphylococci because staph is salt tolerant and ferments mannitol sugar. Acidification indicated by phenol red pH indicator which turns from red to yellow. Path
Simmon's Citrate Agar Slant (SC)
characterizes members of family Enterobacteriaciae based on ability to use citrate as carbon energy source and inorganic ammonium salts as source of nitrogen. Differentiates members of genus Escherichia from genera Enterobacter and Klebsiella. If organism
Starch Agar Plate (SA)
used to differentiate organisms that break down (hydrolyze) starch into smaller molecules of sugar by the enzyme amylase. After inoculation and growth, plate is flooded with IKI (Iodine) which is a reagent that test for the presence of starch. When the re
Urease
an enzyme that catalyzes the hydrolysis of urea, forming ammonia and carbon dioxide
Oxidase
enzyme that causes oxidation with the addition of oxigen
Catalase
common enzyme found in almost all living organisms that are exposed to oxygen; responsible for decomposing hydrogen peroxide into water and hydrogen
Decarboxylation
chemical reaction that releases carbon dioxide
Deamination
removal of animine from molecule with the enzyme deaminases
Amylase
Enzyme that breaks down sugar