Ch.5 Interactive glossary Flashcards
A bacteriological medium that binds oxygen gas from the atmosphere and creates an environment suitable for anaerobic growth.
Thioglycollate broth
A bacterium not inhibited by oxygen gas
Aerotolerant
A chemically defined medium in which the nature and quantity of each component is identified.
Synthetic medium
A chemically undefined medium in which the nature and quantity of each component has not been identified.
Complex medium
A common bacteriological growth medium consisting of beef extract, peptone, and water.
Nutrient broth
A common bacteriological growth medium consisting of beef extract, peptone, water, and agar.
Nutrient agar
A differential growth medium that encourages the growth of staphylococci by containing a high percentage of salt, which is inhibitory to most other microorganisms.
Mannitol salt agar (MSA)
A growth medium containing special nutrients to grow fastidious organisms.
Enriched medium
A growth medium in which different species of microorganisms can be distinguished visually.
Differential medium
A growth medium that contains ingredients to inhibit certain microorganisms while encouraging the growth of others.
Selective medium
A laboratory test in which a statistical evaluation is used to estimate the number of bacterial cells in a sample of fluid; often employed in determinations of coliform bacteria in water.
Most probable number test
A measure of the viable cells by counting the number of colonies on a plate; each colony presumably started from one viable cell.
Colony forming unit
A microbe that grows best without salt but can tolerate low concentrations.
Halotolerant
A microorganism that cannot grow in the presence of added sodium chloride.
Nonhalophile
A microorganism that grows at acidic pHs below 4.
Acidophile
A microorganism that lives under conditions of high atmospheric pressure.
Barophile
A polysaccharide derived from marine seaweed that is used as a solidifying agent in many microbiological culture media.
Agar
A portion of a bacterial growth curve encompassing the first few hours of the population’s history when no growth occurs.
Lag phase
A procedure to estimate the number of cells in a sample dilution spread on an agar plate.
Standard plate count
A process by which a mixed culture can be separated into pure colonies and the colonies isolated
Pour plate method
A process by which a mixed culture can be streaked onto an agar plate and pure colonies isolated.
Streak plate method
A prokaryote requiring relatively high concentrations of salt (NaCl).
Halophile
A prokaryote that has an optimal growth temperature above 80 degrees C.
Hyperthermophile
A prokaryote that is alive but cannot be cultured on any known growth medium.
VBNC
An accumulation or colony of microorganisms of one species.
Pure culture
An archaeal organism living at an extremely acidic pH.
Extreme acidophile
An asexual process in bacterial and archaeal cells by which a cell divides to form two new cells while maintaining genetic constancy.
Binary fission
An extremely resistant dormant cell produced by some gram-positive bacterial species.
Endospore
An inward pinching of the cell envelope during binary fission.
Cytokinesis
An organic substance that helps stabilize the proteins and DNA in a bacterial spore, thereby increasing spore resistance.
Diplocilinic acid
An organism that cannot use oxygen gas for metabolism.
Obligate anaerobe
An organism that does not require or cannot use oxygen gas for metabolism.
Anaerobe
An organism that grows best in an oxygen-reduced environment.
Microaerophile
An organism that grows in temperature ranges of 20 degrees C to 40 degrees C.
Mesophile
An organism that lives at cold temperature ranges of 0 degrees C to 20 degrees C.
Psychrophile
An organism that lives at high temperature ranges of 40 degrees C to 90 degrees C.
Thermophile
An organism that lives in environments with high concentrations of salt.
Halophile
An organism that requires oxygen gas for metabolism.
Obligate aerobe
Each bacterial cell on an agar growth medium that divides to produce a discrete colony.
Colony forming unit (CFU)
Estimation of the number of cells by observation with the light microscope.
Direct microscopic count
One method to produce pure cultures in hardened agar.
Pour-plate isolation method
One method to produce pure cultures on an agar plate.
Streak-plate isolation method
Referring to a prokaryotic cell requiring low oxygen gas and a high concentration of carbon dioxide gas for metabolism.
Capnophilic
Referring to an organism that does not require free oxygen.
Anaerobe
Referring to an organism that grows best in an oxygen-reduced environment.
Microaerophile
Referring to an organism that grows in the presence or absence of oxygen gas
Facultative
Referring to microorganisms that grow at 0 degrees C but have a temperature optima of 20 degrees to 40 degrees C.
Psychrotolerant
Referring to prokaryotes that are viable but not culturable.
Viable but not culturable (VBNC)
The cloudiness of a broth culture due to bacterial growth.
Turbidity
The final portion of a bacterial growth curve in which environmental factors overwhelm the population and induce death; also called death phase.
Decline phase
The final portion of a bacterial growth curve in which environmental factors overwhelm the population and induce death; also called the decline phase.
Death phase
The form of reproduction that maintains genetic constancy while increasing cell numbers.
Asexual reproduction
The initial portion of a bacterial growth curve during which time the cells are preparing for reproduction (binary fission).
Lag phase
The portion of a bacterial growth curve in which the reproductive and death rates of cells are equal.
Stationary phase
The process of spore formation.
Sporulation
The second portion of a bacterial growth curve, in which active growth leads to a rapid rise in cell number.
Logarithmic (log) phase
The third portion of a bacterial growth curve in which the reproductive and death rates of cells are equal.
Stationary phase
The time interval for a cell population to double in number
Generation time
