Adapted to high salt concentrations, which are required for growth.
Extreme halophile
The general term used for organisms capable of growth at 0 degrees C.
Psychrophile
Capable of growth at high temperatures; optimum 50-60 degrees C.
Psychrotroph
Used in media to neutralize acids
Buffer
A phenomenon that occurs when bacteria are placed in high salt concentration.
Plasmolysis
Term used in text for organisms that grow well at refrigerator temperatures; optimum growth is at temperature 20-30 degrees C.
Psychrotroph
Microbes that grow better at high CO2 concentrations
Capnophile
Members of the archaea with an optimum growth temperature at 80 degrees C or higher.
Hyperthermophile
The matrix that makes up biofilm
Hydrogel
An Enzyme acting upon hydrogen peroxide
Catalase
Rhizobium bacteria do this in symbiosis with leguminous plants
Nitrogen fixation
Requires atmospheric oxygen to grow
Obligate anaerobe
Requires atmospheric oxygen, but in lower than normal concentrations.
Microaerophile
Does not use oxygen, but grows readily in its presence.
Aerotolerant anaerobe
Does not use oxygen and usually finds it toxic
Obligate anaerobe
Important source of energy, carbon, nitrogen, and sulfur requirements in complex media
Peptones
Breaks down hydrogen peroxide without generation of oxygen.
Peroxidase
Formed in cytoplasm by ionizing radiation
Hydroxyl Radical
An enzyme that converts hydrogen peroxide into oxygen and water
Catalase
The toxic form of oxygen neutralized by superoxide dismutase.
Superoxide radicals
A component added to some culture media that makes the Petri plate into a self-contained anaerobic chamber.
Oxyrase
Synonym for superoxide anions
Superoxide radicals
Isolation method for getting pure cultures; uses an inoculating loop to trace pattern of inoculum on a solid medium.
Streak Plate
Colonies grow on agar surface for identification
Spread plate
Used to increase the numbers of a small minority of microorganisms in a mixed culture to arrive at detectable level of microorganisms
Enrichment culture
Preservation method that uses quick-freezing and a high vacuum
Lyopholization
Accumulations of microbes large enough to see without a microscope
Colonies
Microbes added to initiate growth
Inoculum
Agar is a(n) _______ derived from a marine alga.
polysaccharide
A few bacteria and the photosynthesizing ________ are able to use gaseous nitrogen directly from the atmosphere.
cyanobacteria
_________ are the most common microbes; their optimum temperatures bare 25-40 degrees C.
mesophiles
Osmotic effects are roughly related to the _________ of molecules in a given volume of a solution.
number
A complex medium in liquid form is called nutrient _______.
broth
For preservation by ________, a pure culture of microbes is placed in a suspending liquid and quick frozen at -50 to -95 degrees C.
deep-freezing
Bacteria usually reproduced by ________ fission.
binary
Turbidity is recorded in a spectrophotometer as _________
absorbance (also optical density)
The growth of filamentous organisms such as fungi is often best recorded by means of ___________.
dry weight measurement
_________ grow more efficiently aerobically than they do aerobically than they do anaerobically
facultative anaerobes
__________ do not require high salt concentrations, but they are able to grow at salt concentrations that may inhibit the growth of many other bacteria.
facultative halophiles
Examples of buffers are ________ salts; peptones and __________ found in complex media are also buffers.
phosphate; amino acids
Any nutrient material prepared for the growth of bacteria in a laboratory is called _________.
culture medium
Agar melts at about the boiling point of water, but remains liquid until the temperature drops to about _______.
40 degrees C
Dilutions of a bacterial mixture are poured into a Petri dish and mixed with melted agar. This plate-counting method is called _________.
pour plate method
Partially digested protein products used in complex media are called _______.
peptones
To grow obligate intracellular parasites such as rickettsias and chlamydias, it is usually necessary to provide _________.
living host cedlls
The general term for tests that estimate microbial growth by the time required for them ti deplete oxygen in the medium is ______ tests.
reduction
The _______ growth temperature is that at which the organism grows best.
optimum
When a single colony arises from a clump of bacteria, it is recorded was a(n)
colony-forming units
Used to grow obligate anaerobes.
Reducing media
Designed to suppress the growth of unwanted bacteria and to encourage growth of desired microbes
Selective media
Generally contain ingredients such as sodium thioglycolate that chemically combine with dissolved oxygen.
Reducing media
Nutrients are digests or extracts; exact chemical composition varies slightly from batch to batch.
Complex media
New cell numbers balanced by death of cells
Stationary phase
No cell division, but intense metabolic activity.
Differential media
A logarithmic plot of the population produces an ascending straight line.
Log phase
Usual laboratory designation for safe handling of tuberculosis bacteria.
BSL-3
Laboratory designation for the most dangerous microorganisms; personnel wear "space suits".
BSL-4
A routine microbiology teaching laboratory would be designated as this.
BSL-1