Lab lecture 2 quiz

Robert Koch

Identified as the Father of Bacteriology.

Koch's Contribution

Found that one bacterium causes the same disease.

Microbiome

The community of microbes that inhabit a particular environment.

Culturing Bacteria

The goal is to grow/culture bacteria collected from the environment.

Growth Medium

Must provide macronutrients, an energy source, and necessary growth factors.

Macronutrients

Sources of carbon, nitrogen, phosphorus, and sulfur.

Chemically Defined Media

The exact chemical composition of each ingredient is known.

Complex Media

The exact chemical composition of each ingredient is not precisely known.

Luria Broth (LB)

A complex medium that supports faster bacterial colony growth.

Tryptones

Peptides formed by digestion of casein by trypsin, supplying organic carbon, energy, and nitrogen.

Yeast Extract

Supplies organic carbon, energy, and nitrogen sources.

Sodium Chloride (NaCl)

Another component of Luria Broth.

Agar

A solidifying agent extracted from red algae.

Sterilization

Any process that removes, kills, or deactivates all forms of life.

Autoclave

Uses steam under pressure to sterilize reagents/materials.

Agar Liquefaction

Agar liquefies at 100°C and remains liquid until it cools to about 40°C.

Inoculate

Intentionally introducing microbes.

Incubate

Allowing microbes to grow on/in media.

Quadrant Streak Procedure

Uses four streaks to obtain isolated bacterial colonies.

Colony

A population of bacterial cells that arises from a single bacterial cell.

Colony-Forming Unit (CFU)

Used to measure the amount of microbes; arises from a group of the same microbes.

Colony Descriptions

Include form, size, elevation, margin, surface, opacity, and color.

Turbid

Cloudy.

Flocculent

Clumps of microbial cells.

Pellicle

A membrane across the surface of liquid.

Sediment

Microbial cells settled at the bottom of the tube.

Aseptic Technique

Procedures used to minimize unwanted contaminants in cultures.

LB Broth

Liquid culture used to grow a large number of bacteria in a small space; contains no agar.

LB Slant

Solid culture that provides an easy method to transport bacteria; contains 1.5% agar.

LB Plate

Used with the quadrant streak method to isolate single colonies; contains 1.5% agar.

LB Deep

Used to grow bacteria that require different oxygen levels; contains 1.5% agar.

Semisolid Deep

Used to determine whether bacteria are motile; contains 0.5-0.7% agar.

Defined Media

Growth medium with an exact chemical composition known.

CFU

Colony Forming Unit; used to measure the number of viable bacteria in a sample.

Colony Description Characteristics

Form, size, elevation, margin, surface, opacity, color.

Quadrant Streak

Technique used to isolate a pure strain from a single species of microorganism.