Microbiology 211 — Chapter 5: Control of Microbial Growth

Vocabulary flashcards covering methods, chemicals, and definitions related to the control of microbial growth based on the Chapter 5 study guide.

Antiseptic

A chemical used on living tissues to reduce or eliminate microorganisms.

Disinfectant

A chemical used on inanimate objects to eliminate most or all pathogens; also called a germicide.

Aseptic technique

A series of procedures that minimize the introduction of undesired microbes to a sterile field, preventing contamination of samples, workers, and the environment.

Sterile

A state of being completely free of all microorganisms and viruses, including endospores; does not account for prions.

Sanitized

A state where the microbial population has been substantially reduced to meet accepted health standards that minimize the spread of disease.

Autoclave

A device that sterilizes using pressurized steam; increased pressure raises the steam temperature enough to kill endospores.

Standard Autoclave Settings

The settings typically used to sterilize liquids are $121\,^{\circ}C$, $15\,\text{minutes}$, and $15\,\text{psi}$ (pounds per square inch).

Fluid Sterilization Filter Pore Size

The maximum pore diameter of a filter that will sterilize fluids is $0.2\,\mu m$ (micrometers), which is small enough to remove bacteria.

HEPA

Abbreviation for High-Efficiency Particulate Air; filters with a pore diameter of $0.3\,\mu m$ that remove nearly all microbes larger than this from the air.

Micron

A unit of measurement equal to one micrometer ($1\,\mu m$).

Ionizing radiation

A sterilization method using Gamma rays and X-rays often used for heat-sensitive laboratory supplies like Petri dishes and pipettes.

Alcohols

A chemical class including ethyl alcohol (ethanol) and isopropyl alcohol (isopropanol), effective at $60\textit{--}80\%$ aqueous solutions.

EtOH

Abbreviation representing ethyl alcohol (ethanol).

Aldehydes

A chemical class used to control microbial growth that includes formaldehyde.

Halogens

A chemical class used to control microbial growth that includes chlorine and belongs to Group $17$ (VIIA) on the periodic table.

Sodium hypochlorite

The chemical found in household bleach; a $1:100$ dilution is effective as a disinfectant.

QUATS

Quaternary Ammonium Compounds; cationic detergents that destroy vegetative bacteria and enveloped viruses by disrupting the cell membrane, though Pseudomonas can resist them.