What is a defined medium?
synthetic medium composed of inorganic salts and usually a carbon source such as glucose-- know exact chemical components in the medium
What is a differential medium?
medium permitting certain organisms to be distinguished from others by the appearance of the coholonies
What is usually in a differential media?
pH indicator
What is a rich or enriched medium?
medium containing many growth factors- usually it is an undefined medium made from meat plant or yeast extracts
What is a selective medium?
media formulated to permit the growth of certain bacteria but not others
What does selective media usually have?
an inhibitor such as a dye, special chemical, NaCl, pH or an antibioticc
What kind of organisms are grown on selective media?
ones that are resistant to inhibitor
What is an undefined media?
complex medium in which the exact amounts of components and their composition are unknown because it made from extracts or enzymatic digest of meat plants or years
What organisms could not grow on the glucose salt medium? Which organisms could grow on it?
staph is the only one that can grow on glucose salt mediums- others could not unless develop mutation for nutritional requirement
What organisms do not require any growth factors?
organism that can grow on glucose salt agar do not need any growth facts
organisms that grow well on TSA but not GSA require growth
Of the organisms that could grow on both TS agar and glucose salts, did organisms grow better on the TS agar than the glucose salts? Can you propose a reason?
organism generally grow better on complex media such as TSA because they do not need to synthesize as many growth factors
Which organisms could grow on the EMB agar?
escheria coli, enterobacter, pseudomonas- not staph
Which organism can ferment lactose
e. coli, enterobacter can ferment lactose- pseudomonas cannot ferment lactose
cannot determine staph because it cannot grow on EMB
Could you differentiate E. coli from other organisms growing on EMB how?
1. produces purple sheen to show that it can ferment lactose- but also produces a green sheen due to the acid that accumulates from its fermentation pathyway
In general, EMB selects for what kind of organisms?
gram negative enteric bacteria
In general, EMB is differential for what kinds of organisms?
lactose fermenting or non lactose fermenting bacteria