Microbiology Pt. 1 Flashcards
Characteristics of Nutrient Agar
contains carbohydrates, amino acids, vitamins, nitrogen source, and salts
Nutrient Agar selective/differential
Neither
Growth of Nutrient Agar
Bacteria, yeast, molds
Characteristics of MacConkey
contains bile salts and crystal violet dye, inhibit Gram (+) growth.
contains neutral red pH indicators
low pH = red
high pH = yellow
MacConkey selective/differntial
both
selective: inhibits Gram (+) growth
differential: ability to ferment lactose
Growth of MacConkey
Gram (-) bacteria
pink/red: able to ferment lactose
Waite/colorless/golden: unable to ferment lactose
Characteristics of Eosin Methylene Blue (EMB)
contains eosin and methylene blue dyes, inhibits Gram (+) growth
Eosin Methylene Blue (EMB) selective/differential
Both
selective: inhibits Gram (+) growth
differential: ability to ferment lactose
Growth of EMB
Gram (-) bacteria
metallic green: E coli
pink/purple/black: able to ferment lactose
colorless: unable to ferment lactose
Characteristics of Blood Agar
contains sheeps blood:
fastidious bacteria that require blood can grow
contains general nutrients:
any kind of bacteria can grow
Blood Agar selective/differential
non-selective
differential: identify organisms that have hemolytic activity
Growth of Blood Agar
colony surrounded by green color: hemolysis (incomplete lysis and digestion)
colony surrounded by white/clear: B-hemolysis (complete lysis/digestion)
Agar under/around colony is unchanged: y-hemolysis (no hemolysis)
When bacteria undergo cell division, they are clones of their patent cell. True/False
True
What are 2 key differences between Prokaryotes and Eukaryotes?
Prokaryotes contain a nucleoid region and eukaryotes do not. Eukaryotes contain a nucleus and prokaryotes do not
Media that prevents the growth of some type of microorganisms and permits the growth of other is said to be…
selective
Media that allows you to tell whether or not a colony has a particular property is called…
different
Nutrient Agar
contains all the nutrients necessary for growth
Eosin Methylene Blue (EMB)
eosin, methylene blue
Blood Agar
blood
Elongated, rod-shaped bacteria are called…
bacill
How does sterilization method prevent growth?
Microorganisms grow rapidly in culture media, and correct transfer techniques and the use of sterile reagents are usually enough to prevent contamination
Gram-positive bacteria…..
have a cell membrane and a thick cell wall
Gram-negative bacteria have….
a cell membrane, a thin cell wall, and an outer phospholipid membrane
Anaerobic bacteria
only grows in absence of oxygen
Photoautotroph bacteria
produces energy using sunlight
Aerobic bacteria
requires oxygen to grow
Facultative bacteria
survives best a low oxygen
Chemoautotroph bacteria
obtains its energy through chemicals
Pathogenic bacteria
causes disease
