Chapter 3

is one of the Five I's involved in culturing microorganisms and involves determining the type of microbe usually to the species level.

Identification

The polysaccharide found in seaweed that is commonly used to prepare solid culture media is called ______.

agar

A reducing medium is used to culture ______.

anaerobic bacteria

Some organisms ferment certain carbohydrates to produce an acidic byproduct while others don't. What component of mannitol salt agar makes this media differential?

Both the mannitol and the phenol red

True or false: In completing all steps of the Five "I" process used for culturing microorganisms, "identification" of microorganisms can be accomplished before inoculation.

False

True or false: Isolation of colonies usually requires a large number of cells to be inoculated over an expansive area of medium.

False

These tubes show three organisms growing on triple sugar iron medium. This differential medium can give a microbiologist information about pH changes that occur during growth by the use of _____ in the medium

dye

True or false: Agar is defined as a polysaccharide from seaweed that is used to keep nutrients in liquid form.

false

Bacteria that require growth factors and complex nutrients are termed

fastidious

Most of the time, microbes in natural circumstances exist ______.

in relationship with other species

Liquid is one of the ______ states which is used to classify microbial media

physical

The is a property used to classify media and refers to the medium's normal consistency, be it liquid, semisolid, solid, or solid.

physical state

A _____ medium contains a substance that absorbs oxygen and is often used to culture anaerobic bacteria

reducing

A _____ medium contains a substance that absorbs oxygen and is often used to culture anaerobic bacteria.

reducing

True or false: A colony is defined as a cluster of millions of microorganisms which grow from a single cell living on a solid medium.

True

True or false: Following the Five I's used for culturing microorganisms, isolation must occur prior to inspection.

True

A nutrient medium supplemented with blood, serum, or some growth factors to promote the multiplication of fastidious microorganisms is called a(n

enriched

True or false: Following the Five I's used for culturing microorganisms, inoculation occurs after isolation.

false

A(n) ______ is an organic compound such as a vitamin or amino acid that must be provided in the diet to facilitate survival of certain bacteria.

growth factor

Enzymes that break down red blood cells to release the hemoglobin for growth are termed ______.

hemolysins

A(n) is a temperature-controlled chamber that provides the proper temperature conditions for microbial multiplication in the culturing process.

incubator

Broths are characterized by being ______.

liquid, water based, and not able to solidify at temperatures above freezing

Selective media are used for the ______.

primary isolation of a specific microbe

The purpose(s) of isolation in the culturing of microorganisms includes ______.

producing a discrete colony of just one species the ability to observe individual colony morphology

A medium that contains one or more agents that inhibit the growth of a certain microbe or microbes but not others is termed

selective

media are important in primary isolation of a specific type of microorganism from samples containing many other species such as saliva or feces

selective

Media with a firmness midway between that of a broth (a liquid medium) and an ordinary solid medium are called

semisolid media

Which types of media contain at least one ingredient that is not chemically defined?

synthetic, complex

Growth factors are defined as an organic compound such as a vitamin or amino acid that must be provided in the diet to facilitate growth; an essential nutrient.

true

Mannitol salt agar is defined as both a selective and a differential agar since it selects against non-halophiles and allows the researcher to distinguish between organisms that vary in their ability to ferment mannitol.

true

True or false: A broth can be defined as being liquid, water based, and not able to solidify at temperatures above freezing.

true

True or false: Semisolid media are media types which have a fairly gelatinous consistency which allows microbiologists to observe motility in some microorganisms.

true

Which of the following describe selective media?

Suppress unwanted organisms Encourage the growth of desired organisms

Select the characteristics of complex media used in microbial culturing

They provide a rich mixture of nutrients for microbial growth. They may contain blood, serum, or meat extracts. Examples include chocolate agar and MacConkey agar.

Which of the following are required for proper isolation of microorganisms?

Agar in a petri dish Inoculation tools

Select the type of media where the chemical composition is precisely known

Defined

A fastidious organism must be grown on what type of medium?

Enriched medium

Which of the following identifies the step in the Five I's of culturing microorganisms during which a culture is placed in a controlled environment to encourage growth?

Incubation

Which one of the following is NOT part of the 5 basic techniques used to grow, examine and manipulate microorganisms in the laboratory (recall the Five I's)?

Infection

Which of the following are part of the 5 basic techniques used to grow, examine and manipulate microorganisms in the laboratory (recall the Five I's)?

Inoculation Isolation Inspection

Microbial media can be classified as which of the following physical states?

Liquefiable Liquid Semisolid

Selective media that are used to isolate intestinal pathogens include ______

MacConkey agar Hektoen enteric agar

Which of the following are characteristics of an enriched medium?

May contain organic substances such as blood, serum or hemoglobin. May contain special growth factors. Can be used to aid in the growth of fastidious organisms

What methods can be used to isolate bacteria?

Quadrant streak plate Bright field microscopy Loop dilution Spread plate Gram stain

Which is true for fastidious organisms?

Require growth factors and/or complex nutrients

This carbohydrate fermentation medium can be used to determine if a microbe produces gas during growth, by looking for ______.

a bubble in the inverted tube

Viruses are commonly grown in/on _______.

animal cells or tissues

The identities of microorganisms on our planet

are still mostly unknown

All of the following are properties used to classify media, except:

color

A medium that works by showing two reaction types, such as a color change in some colonies but not in others is called a ______ medium.

differential

Media that allow the growth of multiple types of microbes but are designed to distinguish characteristics among members of the culture are called ______ media.

differential

The name given to media which allow different types of microbes to grow but are designed to display visible morphological or chemical differences among those microbes is

differential

This carbohydrate fermentation medium can be used to determine if a microbe produces gas during growth, because any gas produced will be trapped in the inverted tube. This is an example of a _____ medium.

differential

This medium contains a dye to indicate a pH change that occurs in the medium during the growth of the microbes. It is best described as a(n) _____ medium.

differential