Labs 3- 5, 6A, 6B, 6D and Outbreaks

Question 1

Lab #3
Define culture media

Answer 1

Mixture of material is used to grow microbes.

Question 2

What are the five basic ingredients of culture media?

Answer 2

Carbon, nitrogen, minerals, buffer, and water.

Question 3

Complex media

Answer 3

A.k.a. crude ingredients. Has all 5 components necessary for growth of microorganisms, but exact amount of each unknown element is unknown.

Question 4

Defined media

Answer 4

Chemically defined media. All ingredients needed for microorganisms growth and come with chemical formula and amount of each element is known.

Question 5

Pure culture

Answer 5

Culture with only one species

Question 6

Liquid/broth media

Answer 6

Liquid at room temperature and are typically contained within tubes or flasks.

Question 7

Define Turbidity, Pellicle formation, and sediment

Answer 7

Turbidity- Cloudiness in the liquid
Pellicle formation- thin coat of cells, floating on top of broth
Sediment - deposit of cells at the tube bottom that were swirl upward if tube is tapped gently.

Question 8

Solid media

Answer 8

The same as the broth media, except has a solidifying agent (usually agar). Liquid when hot and solid at room temperature.

Question 9

Why can agar be used?

Answer 9

Most microorganisms do not use agar as a nutrient source.

Question 10

Agar tubes (deeps)

Answer 10

Agar will solidify at bottom of glass culture tubes maintained in a vertical position. Used to test the ability of bacteria to catabolize nutrients under anaerobic conditions since air is not readily able to penetrate the media.

Question 11

Agar slants

Answer 11

formed when tubes of molten, a gar containing media are placed on an angle during cooling. Tube contents hardens with the slanted or slope surface that can be easily in oculated. Commonly used to maintain stock cultures because they provide a broad surface for growth and observation, but do not dry out as fast as agar plates.

Question 12

Agar plates

Answer 12

Molten agar media poured into patriot plates. Will cool to form broad, thin slabs of solid media. Allows for mixtures of different bacteria types to be inoculated in colonies of individual types to be easily separated from one another for isolation and identification.

Question 13

Pseudomonas

Answer 13

Use sodium benzoate eight as a carbon source.

Question 14

Azotobacter

Answer 14

Nitrogen fixing bacteria. These organisms can use and two from the atmosphere as their source of nitrogen so no source of nitrogen is included in their medium.

Question 15

Lab #4
Streak plate method

Answer 15

A successful, executed streak plate will yield well spaced, isolated colonies from the same species. The main objective of this technique is to dilute the culture to produce while isolated colonies.

Question 16

Aseptic technique

Answer 16

Be able to inoculate media with desired pure cultures without introducing any other organisms.

Question 17

Inoculation loop

Answer 17

Two used to transfer bacteria from cultures grown on solid media. Use a small volume of cells for routine inoculations.

Question 18

Petri plates are always incubated agar side-down

Answer 18

False

Question 19

How should plates be labeled?

Answer 19

First initial, last name in full, identity of culture used, current date, and type of medium used.

Question 20

Lab #5
Define colony

Answer 20

Mass of cells visible to the naked eye, and represents a clone of cells arising from a single vegetative cell, a spore, or a number of cells connected together in a chain or cluster.

Question 21

Define morphology

Answer 21

Defined as the science or study of form, or external appearance, without regard to function (size, shape, color, etc.)

Question 22

Another name for morphological features

Answer 22

Cultural characteristics

Question 23

Form

Answer 23

Shape of whole colonies, growing on agar surface.
Punctiform (less than 1mm in diameter), Circular, irregular, filamentous (fuzzy), and rhizoid (root-like).

Question 24

Margin

Answer 24

The edge of an individual colony.
Described as entire (smooth edge), undulate (wavy), lobate (cloud), serrate (serrated butter knife), filamentous (fuzzy/tree like), curled (rings).

Question 25

Elevation

Answer 25

Flat, raised, convex, pulvinate (dome-shaped), umbonate (lump in center) or referred to with indentation/crater in center but some refer that as crateriform.

Question 26

Surface texture

Answer 26

Always describe using two terms. One to describe the smoothness of the surface (ex. Smooth, rough, or wrinkled.) the other term would be used to describe the sheen of the surface (shiny, glistening, door, dry, or powdery.)

Question 27

Optical character

Answer 27

Described as either opaque or translucent. Place over page with paper with print. If the print can be seen through the isolated colony, it is translucent. If not see through, it is opaque. Some will be fluorescent (glow when exposed to ultraviolet light) or bioluminescent (produce their own light.)

Question 28

Lab 6A
Direct staining

Answer 28

Cells are colored, but leaves background colorless.

Question 29

Indirect staining/negative staining

Answer 29

Colors the background, but leaves the cells uncolored.

Question 30

Basic stain

Answer 30

Color associated with positive ion (cation). Used in direct standings. Ex. Methylene, blue, crystal violet, and safranin.

Question 31

Acidic stain

Answer 31

Color associated with negative ion (anion). Used an indirect staining. Ex Congo red

Question 32

What is the advantage of indirect staining over direct standing?

Answer 32

It causes less cellular distortion, so cells retain their actual size and shape.

Question 33

Define smear

Answer 33

A mixture of liquid (usually water) and micro organisms on the surface of a glass slide, and is most useful if thin and uniform in consistency. Less is more.

Question 34

Defined the procedure of Heat fixing

Answer 34

Involves passing a slide containing back to your cell through a flame. This reduces potential hazard of handling slide containing pathogenic microorganisms.

Question 35

Define the procedure of wet mount

Answer 35

used to determine motility of an organism (running and tumbling). The presence of bacterial flagella can be inferred by observing living bacteria under the microscope while they are fresh (24-48 hours) bacteria demonstrate running in tumbling movement if they are considered motile which infers they have flagella.

Question 36

Lab 6D
Special stains/structural stains

Answer 36

Direct staining techniques that include endospore capsule and flagellar stains. Allow for differentiation of specific back to your structures found either inside or outside of cells.

Question 37

Bacterial endospores

Answer 37

Dormant structures produced by a variety of bacterial species, which are highly resistant to heat, desiccation, and toxic chemicals. Resistant to staining, but one stand are highly resistant to being decolorized. Older cells will often degenerate, leaving their spores now called exospores behind in the environment.

Question 38

Define sporangium

Answer 38

Spore containing cell. Can only contain one cell at a time.

Question 39

Malachite green

Answer 39

Primary stain in endospore stain. Direct stain to cells and colors the cells and endospores green (if any).

Question 40

Outbreak!
Bactria that causes Pneumococcal pneumonia?

Answer 40

Streptococcus pneumoniae

Question 41

Outbreak!
Bacteria that causes MRSA?

Answer 41

Staphylococcus aureus

Question 42

Outbreak!
Bacteria that causes Tuberculosis?

Answer 42

Mycobacterium tuberculosis

Question 43

Outbreak!
Bacteria that causes Dental caries

Answer 43

Streptococcus mutans