Aerobic using
oxygen for metabolism.
Anaerobic not
using oxygen for metabolism. Some anaerobes cannot survive
in the presence of oxygen.
Agar plate a
medium made solid by the addition of agar, a seaweed derivative.
The medium contains specific
nutrients for culturing specific microbes
. Aplate is most often prepared in
a petri dish.
Archaea a
domain of life believed to be the most ancient and to contain
organisms believed to be similar to
ancient prokaryotes. This domain of
unicellular organisms includes the
halophiles, organisms that grow in high-salt
environments; methanogans,
anaerobes that produce methane; and
thermophiles, which thrive in
high-temperature environments.
Bacteriorhodopsin a
red pigment that enables some microbes to turn solar
energy into chemical energy.
Binary fission splitting
of a parent cell into two daughter cells.
Carotenoids a
group of pigments ranging from yellow to red that occur widely
among a variety of organisms. They
help protect Halobacterium from the
harmful effects of UV radiation.
Clone a
genetic duplicate of an organism. A microbial colony consists of
clones of the founding cell.
Colony a
visible cluster of millions of microbial cells resulting from binary
fission of a founder cell and its
daughters and so on.
Colony-forming unit (cfu) a
microbial cell capable of undergoing binary
fission and founding a colony.
Generation time length
of time for a particular microbe to complete its
division cycle to form two new
daughter cells.
Genotype the
genetic makeup of an organism, either in total or in terms of
one or a few sets of alleles.
Incubate to
furnish appropriate conditions for an inoculated solid or liquid
medium to produce colonies or
larger populations of the inoculated microbes.
Inoculum living
material used to initiate a culture of microbes
Insertion sequences (IS elements) sections
of DNA that insert at random
into the genome, causing mutations
that often bring about phenotypic change;
also known as “jumping genes.”
Lyse to
cause the breaking open of a cell wall and membrane such that the
contents are released and the cell
dies (the breaking open itself is referred to
as “lysing”).
Medium substrate
or material on or in which microbes are grown for study.
Microbiology the
study of single-celled life forms.
Pathogen a
disease-causing agent.
Phenotype observable
characteristic of an organism, e.g., brown, blue, or
green eyes in people.
Pure culture colony
or collection of microorganisms containing only one
type. A pure culture is usually
obtained after a series of cultures has been
performed to isolate a particular
microbe.
Salinity measure
of the proportion of salt in a substance. Aquatic halophiles
live in water of high salinity.
Solar salt production collection
of sea salt by means of flooding shallow pools
and allowing the sun to evaporate
the water. The brine is moved to pools of
successively higher salt
concentration until crystals form.
Sterile technique (aseptic
technique) accepted laboratory practices geared
toward preventing contamination of
cultures and the laboratory and
surroundings. Sterile technique
covers procedures regarding lab preparation,
transfer of cultures, and cleanup
and disposal.
Streak to
spread a microbial sample over the surface of a plate in order to
isolate colonies. Usually,
streaking is done as a pattern of zigzags.
