| acidophile |
A
microorganism that has its growth optimum between about pH 0 and 5.5. (p. 125) |
| aerobe |
An organism that grows
in the presence of atmospheric oxygen. (p.129) |
| aerotolerant anaerobe |
Microorganisms
that grow equally well whether or not oxygen is present. (p. 129) |
| anaerobe |
An organism that grows
in the absence of free oxygen. (p. 129) |
| barotolerant |
Organisms
that can grow and reproduce at high pressures but do not require them. (p. 130,
846) |
| batch
culture |
A culture of
microorganisms produced by inoculating a closed culture vessel containing a single batch
of medium. (p. 114) |
| chemostat |
A
continuous culture apparatus that feeds medium into the culture vessel at the same rate as
medium containing microorganisms is removed; the medium in a chemostat contains one
essential nutrient in a limiting quantity. (p. 121) |
| coenocytic |
Refers to a
multinucleate cell or hypha formed by repeated nuclear divisions not accompanied by cell
divisions. (p. 114, 526) |
| colony forming units (CFU) |
The
number of microorganisms that can form colonies when cultured using spread plates or pour
plates, an indication of the number of viable microorganisms in a sample. (p.
118) |
| continuous
culture system |
A culture system with
constant environmental conditions maintained through continual provision of nutrients and
removal of wastes. (p. 121) |
| facultative anaerobe |
Microorganisms
that do not require oxygen for growth, but do grow better in its
presence. (p.129) |
| generation
time |
The time required for a
microbial population to double in number. (p.115) |
| halophile |
A
microorganism that requires high levels of sodium chloride for growth. (p.124) |
| lag
phase |
A period following the
introduction of microorganisms into fresh culture medium when there is no increase in cell
numbers or mass during batch culture. (p.114) |
| log phase |
The
phase of the growth curve during which the microbial population is growing at a constant
and maximum rate, dividing and doubling at regular intervals. (p.114) |
| obligate
aerobe |
Organisms that grow only
in the presence of oxygen. (p. 129) |
| obligate anaerobe |
Microorganisms
that cannot tolerate the presence of oxygen and die when exposed to it. (p.129) |
| stationary
phase |
The phase of microbial
growth in a batch culture when population growth ceases and the growth curve levels
off. (p.115) |
| superoxide dismutase |
An
enzyme that protects many microorganisms by catalyzing the destruction of the toxic
superoxide radical. 130 |
| turbidostat |
A continuous culture
system equipped with a photocell that adjusts the flow of medium through the culture
vessel so as to maintain a constant cell density or turbidity. 121 |
