Chapter 3 Flashcards
The visible accumulation of microorganisms in or on a nutrient medium. Also, the propagation of microorganisms with various media
culture
A nutrient used to grow organisms outside of their natural habitats
medium
The implantation of microorganisms into or upon culture media.
inoculation
Completely free of all life forms, including spores and viruses
sterile
To isolate a sample culture in a temperature-controlled environment to encourage growth.
incubate
Growth-supporting substance in fluid form
liquid media
Nutrient media with a firmness midway between that of a broth (a liquid medium) and an ordinary solid medium; motility media
semisolid media
Material used to promote the growth of a broad array of microbes
general purpose media
A nutrient medium supplemented with blood, serum, or some growth factor to promote the multiplication of fastidious microorganisms
enriched medium
An organic compound such as a vitamin or amino acid that must be provided in the diet to facilitate growth. An essential nutrient.
growth factors
Requiring special nutritional or environmental conditions for growth. Said of bacteria
fastidious
Nutrient media designed to favor the growth of certain microbes and to inhibit undesirable competitors
selective medium
A single substrate that discriminates between groups of microorganisms on the basis of differences in their appearance due to different chemical reactions
differential media
Any biological agent that is capable of destroying red blood cells and causing the release of hemoglobin.
hemolysin
A growth medium that absorbs oxygen and allows anaerobic bacteria to grow
reducing medium
A growth medium that contains sugars that are converted to acids through fermentation. Usually contains a pH indicator to detect acid protection
carbohydrate fermentation media
Microbiological medium that is used to transport specimens
transport media
Microbiological medium used to test the effects of specific treatments to bacteria, such as antibiotic or disinfectant treatment
assay media
Microbiological medium that does not encourage growth and allows for the counting of microbes in food, water, or environmental samples
enumeration media
A macroscopic cluster of cells appearing on a solid medium, each arising from the multiplication of a single cell.
colony
A tool used in the microbiology laboratory sometimes comprised of a platinum or nichrome wire loop attached to a heat-proof handle
inoculating loop
A container growing a single species of microbe whose identity is known
pure culture
A sterile state such as a pure culture.
axenic
To make a second-generation culture from a well-established colony of organisms
subculture
A container growing two or more different, known species of microbes
mixed culture
A medium that once held a pure (single or mixed) culture but now contains unwanted microorganisms
contaminated culture
An impurity; any undesirable material or organism
contaminant
In optics, the bending of light as it passes from one medium to another with a different index of refraction
refraction
An image formed at the focal plane of a convex lens. In the compound light microscope, it is the image created by the objective lens
real image
In optics, an image formed by diverging light rays; in the compound light microscope, the second, magnified visual impression formed by the ocular from the real image formed by the objective
virtual image
The capacity of a microscope lens system to accurately distinguish between two separate entities that lie close to each other. Also called resolution
resolving power
The measurement of the degree of light that is bent, or refracted, as it passes between two substances such as air, water, or glass
refractive index
A method for coloring microbial specimens that involves a chemical that sticks to the specimen to give it color
positive stain
A staining technique that renders the background opaque or colored and leaves the object unstained so that it is outlined as a colorless area
negative stain
Type of positive staining technique that uses a single dye to add color to cells so that they are easier to see. This technique tends to color all cells the same color
simple stains
A technique that utilizes two dyes to distinguish between different microbial groups or cell parts by color reaction
differential stains
A differential stain for bacteria useful in identification and taxonomy. Gram-positive organisms appear purple from crystal violet mordant retention, whereas gram-negative organisms appear red after loss of crystal violet and absorbance of the safranin counterstain
gram stain
A solution containing carbol fuchsin, which, when bound to lipids in the envelopes of Mycobacterium species, cannot be removed with an acid wash
acid-fast stain
In describing microbial developmental stages, a metabolically active feeding and dividing form, as opposed to a dormant, seemingly inert, nondividing form
vegetative
Any staining method that highlights the outermost polysaccharide and/or protein structure on a bacterial, fungal, or protozoal cell
capsule staining
A staining method that highlights the flagellum of a bacterium
flagellar staining
