[BIO 120.11] Module 3 Part 1: Culturing Bacteria - Culture Media

Culture Media, Incubation Conditions

What are 2 of the growth requirements for culturing bacteria?

Growth, Reproduction

Culture media is essential for what bacterial processes?

TRUE

T/F: For bacteria, the primary indicator of growth is increase in number of cells

FALSE

T/F: For bacteria, the primary indicator of growth is increase in cell size

Culture Media

Source of energy and building blocks for the synthesis of new cell material

Micronutrients and Macronutrients

Culture media is the source of what nutrients?

Macronutrients

Nutrients required in large amounts

Protein (55%), RNA (20.5%)

The macromolecule that has the highest percent of dry weight (__) is ___, followed by ___ (__)

LPS is only found in outer membrane, 3.4%

Why is LPS only found in low concentrations in terms of % of dry weight? What is the %?

DNA, 3.1%

What macromolecule has the lowest % of dry weight? What is the % of dry weight?

50% C, 20% O, 14% N, 8% H, 3% P

What are the top 5 elemental composition of an E. coli cell in terms of dry weight?

TRUE

T/F: All macromolecules require Carbon

FALSE

T/F: Only carbohydrates require Carbon

Organic Polymers, Monomeric constituents of macromolecules

Source of carbon for heterotrophs?

CO2

Source of carbon for autotrophs?

Heterotroph will not grow

If you grow a heterotroph on a minimal media and place it near the window, what will happen to it?

Cyanobacteria (autotroph) will grow because it can fix CO2 from the air

If you grow cyanobacteria on a minimal media and place it near the window, what will happen to it?

TRUE

T/F: All macromolecules contain Oxygen

FALSE

T/F: Not all macromolecules contain Oxygen

Water

What is the source of oxygen for culture media?

Protein, Nucleic Acid, LPS

What 3 macromolecules contain Nitrogen?

Ammonia (NH3)

What is the source of Nitrogen for all microorganisms?

Nitrate (NO3-)

What is the source of Nitrogen for many microorganisms?

Nitrogen gas (N2)

What is the source of Nitrogen for nitrogen-fixing bacteria?

Organic polymers, Monomeric constituents of macromolecules

What are the sources of Nitrogen for heterotrophs?

The nitrogen fixers can still grow

If you leave a plate of nitrogen fixers on minimal media without any nitrogen source in an open space, what will be expected of their growth?

Tryptone, Beef Extract, Casein

Examples of medium ingredients that are rich in Nitrogen

FALSE

T/F: Nitrogen is needed by all macromolecules

TRUE

T/F: Nitrogen is only needed by select macromolecules

TRUE

T/F: Hydrogen is needed by all macromolecules

FALSE

T/F: Hydrogen is needed only in select macromolecules

TRUE

T/F: Phosphorus is needed only by select macromolecules

FALSE

T/F: Phosphorus is needed by all macromolecules

Water

What is the source of Hydrogen in a culture media?

Nucleic Acids, Phospholipids

What organic molecules require Phosphorus?

Inorganic phosphate compounds

What is the source of Phosphorus in a culture media?

TRUE

T/F: Sulfur is needed only for select macromolecules

FALSE

T/F: Sulfur is needed by all macromolecules

Inorganic S, Organic Sulfur Compounds

What are the 2 main sources of Sulfur in culture media?

Sulfate compounds, Sulfide compounds

What are two examples of inorganic S sources?

Vitamins (Thiamine, Biotin)
Amino acids (Cysteine, Methionine)
Lipoic Acid

What are three examples of organic sulfur compounds?

Micronutrients

Nutrients that are required in minute amounts

Trace Metals (Metals), Growth Factors (Organic Nutrients)

What are two types of micronutrients?

Micrograms

What is the unit used for micronutrients, given that they are required in very small amounts?

Stock solution then dilute

How do we prepare micronutrient solutions?

Defined Media, Complex Media

What are the 2 types of media based on composition?

Defined Media

Media Type - Composition: Prepared by adding precise amounts of highly purified inorganic or organic chemicals to distilled water

Highly purified

For defined media, the inorganic and organic chemicals that are added to distilled water must be in what condition?

Exact qualitative and quantitative composition

Describe Defined Media in terms of qualitative and quantitative composition

Simple Defined Media

The recipe shown in the image is an example of what kind of media?

Simple, Complex

What are the 2 types of Defined Media?

Simple Defined Media only have a single C source, Complex Defined Media have more than one C source

How do we differentiate between simple and complex media (under defined media)?

Complex Media

Media Type - Composition: Employ digests of microbial, animal, or plant products, or any of a number of other highly nutritious yet impure substances

Complex Media

The recipe shown in the image is an example of what kind of media?

Casein (milk), Beef extract, Peptone (protein hydrolysate), Tryptic soy broth (soybeans), Yeast extract

What are 5 examples of complex components found in complex media? [Pep CaBeTryYes]

Liquid Medium, Semi-solid Medium, Solid Medium

What are 3 Types of Culture Media Based on Fluidity or Consistency?

FALSE

T/F: Agar is both a solidifying and nutritional agent.

Agar will liquefy

If agar can be used by bacteria as a nutrient source, what is the expected result for the agar?

Broth

Alternative term for liquid media

0%

Percentage of agar in liquid medium

Propagation, Physiology studies

What are the 2 purposes for liquid media?

Liquid Medium

If we want to study gas production with a Durham tube, what kind of medium (based on consistency) should be used?

If you use liquid media, you just need to centrifuge. If you use solid medium, you will still need to scrape

Why is using broth or liquid media better for propagation studies?

0.2% to 0.5%

What is the percentage of solidifying agent in a semi-solid medium?

Motility, Oxygen Requirements, Swarming

What specific characteristics of bacteria can be studied using a semi-solid medium?

Aerobes on top, Anaerobes on bottom

If using a semi-solid medium for determining bacterial oxygen requirements, what results can be expected?

1.5% to 2%

What is the percentage of solidifying agent for solid media?

Morphology, Isolation, Enumeration

What can be studied or done using solid media? MIE

TRUE

T/F: We can use liquid medium or broth for enumeration.

FALSE

T/F: Only solid medium can be used for enumeration (i.e.: CFU)

TRUE

T/F: You can use liquid medium or broth for isolation

FALSE

T/F: Solid media is the only media type that can be used for isolation

Anaerobes

What kind of bacteria is best isolated using broth or liquid medium?

General Purpose, Enriched, Selective, Differential, Characteristic

What are the 5 types of media based on use? GESDC

General Purpose Media

Media Type - Use: Supports almost all microbial growth

TRUE

T/F: In General Purpose Media, there are no inhibitory substances

FALSE

T/F: We can put inhibitory substances in a General Purpose Media

Nutrient Agar

What is an example of General Purpose Media?

General Purpose Media

What is the media type shown in the image?

Enriched Media

Type of media (according to use) that involves the use of growth stimulants

Increase number of desired microorganisms to detectable level

What is the purpose of an enriched media?

Enriched Media

What kind of media is shown in the image

FALSE

T/F: Enriched Media can suppress the growth of other bacteria

TRUE

T/F: Enriched media do not suppress the growth of other bacteria

Fastidious and Slow Growing Microorganisms

What kind of microorganisms work best for enriched media?

Fastidious Microorganisms

Microorganisms that have complex nutritional requirements

Blood Agar

What is an example of enriched media?

Growth Stimulant (serum, blood, other nutritious substances)

What is a key ingredient in enriched media?

TRUE

T/F: Enriched medium is recommended for slow-growing bacteria

FALSE

T/F: Enriched media is not recommended for slow-growing bacteria

TRUE

T/F: Enriched media does not make the isolation process of desired bacteria easier.

FALSE

T/F: Enriched media makes the isolation process of desired bacteria easier.

Selective Media

Media type (according to use) that can inhibit the growth of unwanted microorganisms and can encourage the growth of particular microorganisms.

TRUE

T/F: Aside from inhibiting the growth of unwanted microorganisms, selective media can also encourage the growth of particular organisms.

FALSE

T/F: Selective media can only inhibit the growth of unwanted microorganisms, but not enrich or encourage the growth of particular organisms

Inhibitors (antibiotics, dyes, toxic compounds, detergents)

What is a key ingredient for Selective Media

Mannitol Salt Agar

What is an example of selective media?

Staphylococcus aureus

A microorganism capable of fermenting Mannitol

Selective Media

What is the category of the media shown in the image?

Characteristic Media

Media type (according to use) that functions for determination of metabolic activity, products, or growth requirements