UNIT 2 CULTURE MEDIA Flashcards
the study of microorganisms such as
bacteria, protozoa, fungi and similar organisms that
can’t be seen with the naked eye.
Microbiology
The need to study
these minute organisms started when scientists
discovered the association of microbes to specific
Diseases
increase in cell number through binary fission
Microbial Growth
cell simply splits into two cells, producing two identical cells
Binary Fission
time required for a cell to divide, and its population to double
Generation Time
cells form an initial outgrowth (a bud) that enlarges its size until it approaches that of a parent cell, and
then it separates
Budding
microbes that grow and multiply in or on a culture medium
Culture
a group of descendants of an original cell
Colony
aka axenic; contains a single microbial species
Pure Culture
PSYCHROPHILES
− sensitive to
temperatures over
20˚C
− optimum growth at
15˚C or below
− sensitive to
temperatures over
20˚C
− optimum growth at
15˚C or below
PSYCHROPHILES
PSYCHROTROPHS
optimum growth at
20˚C to 30˚C
optimum growth at
20˚C to 30˚C
PSYCHROTROPHS
MESOPHILES
optimum growth at
25˚C to 40˚C
optimum growth at
25˚C to 40˚C
MESOPHILES
THERMOPHILES
optimum growth at
50˚C to 60˚C
optimum growth at
50˚C to 60˚C
THERMOPHILES
Extreme
Thermophiles
grow at 80˚C or
higher
ACIDOPHILES
− grow at very low pH (0.1 to
5.4)
− Lactobacillus acidophilus
NEUTROPHILES
grow at pH 5.4 to 8.5
Lye water
− grow at very low pH (0.1 to
5.4)
− Lactobacillus acidophilus
ACIDOPHILES
grow at pH 5.4 to 8.5
Lye water
NEUTROPHILES
ALKALIPHILES
− grow at high pH (7 to 12)
− Vibrio cholerae
require very high salt conc. 20 to 30%
aka extreme halophiles
OBLIGATE HALOPHILES