Microbiology Labs: Methods of Culturing Microorganisms

These flashcards cover important terms and concepts related to microbiology lab methods and cell biology, particularly focusing on microbial culturing techniques, cell structures, and staining methods.

Inoculation

The introduction of a tiny sample (inoculum) into a container of nutrient medium for culturing microorganisms.

Incubation

The process where inoculated media is placed in a temperature-controlled chamber to promote growth.

Sterile

The complete absence of viable microbes.

Aseptic

Refers to the prevention of infection/contamination.

Culture

The observable growth that happens in or on a medium.

Inspection

The staining of the bacteria to observe features under a microscope.

Isolation

The process of separating individual bacterial cells to grow discrete colonies.

Colony

Groups of cells large enough to be seen without a microscope.

Glycocalyx

Sugary substances covering the cell, made of polysaccharides and/or polypeptides.

Capsule

A neatly organized and firmly attached type of glycocalyx.

Slime layer

An unorganized and loose type of glycocalyx.

Peptidoglycan

A polymer that makes up the bacterial cell wall, contributing to cell shape and rigidity.

Gram-positive bacteria

Bacteria with a thick cell wall that stain purple in a Gram stain procedure.

Gram-negative bacteria

Bacteria with a thin peptidoglycan layer that stain colorless or red in a Gram stain.

Differential Staining

A technique used to distinguish different types of bacteria based on their cellular structure.

Basic dye

A dye that is positively charged and binds to the negatively charged components of cells.

Acidic dye

A dye that is negatively charged, staining the background instead of the cell.

Simple stain

A staining technique that uses a single dye to color all cells the same color.

Gram Stain

A staining method that classifies bacteria based on their cell wall characteristics.

Eukaryotic cells

Cells that have a nucleus and membrane-bound organelles, compared to prokaryotic cells.

Prokaryotic cells

Cells that lack a nucleus and membrane-bound organelles, including bacteria and archaea.

Bacillus

rod shaped

coccus

spherical shaped

spiral

vibrio, spirillum, spirochete

strep-

in a chain

staphyl- 

cluster

tetrad

4 cell arrangement

sarcinea

4 cell arrangement

dipplococci, diplobaci

2 cell arrangement

vibrio

spirillum

spirochete

dipplococi

streptococci

tetrad

sarcinae

single bacillus

diplobacilli

streptobacili

coccobacillus

star shaped bacteria

what structures are found in all bacteria?

• Cell wall

• Plasma membrane

• Cytoplasm (containing simple cytoskeleton structure)

• Nucleoid containing DNA

• 70s Ribosomes

what structures are external to the cell wall?

• Glycocalyx

• Flagella

• Axial filaments

• Fimbriae

• Pili

Functions of the glycocalyx

• Protect bacteria from phagocytosis

• Enables adherence

• Prevent dehydration

• Source of nutrient

flagella

Thread-like structures that enable bacterial motility and movement by rotating.

flagella: flagellin

protein subunits that make up the filament of bacterial flagella.

flagella: hook

the structure connecting the filament and the motor that allows for the rotation of the flagellum.

flagella: basal body

the structure that anchors the flagellum to the cell membrane and drives its rotation.

taxis

a movement response of microorganisms towards or away from chemical or physical stimuli, facilitating adaptation and survival.

peritrichous

monotrichous and polar

lophotrichous and polar

amphitrichous and polar

what is the functions of bacterial

• Prevents osmotic lysis

• Maintains the cell’s shape

• Contributes to bacteria pathogenicity

• Differential Stain