Culture Media for Microbiology

This set of vocabulary flashcards covers the definitions, history, composition, and classification of bacterial culture media based on lecture notes.

Culture Media

Nurtient-rich substances used to grow (culture) bacteria for identification and study.

Isolation

The process of growing bacteria separately on culture media to obtain them as a pure culture for study.

Louis Pasteur

The scientist who used original media such as urine or meat broth for bacterial growth.

Robert Koch

The scientist who used cooked cut potato as the earliest solid medium.

Colony

A macroscopically visible collection of millions of bacteria originating from a single bacterial cell.

Liquid medium growth

Characterized by diffuse growth within the medium; often referred to as broth.

Solid medium growth

Characterized by the appearance of discrete colonies.

Gelatin

A solidifying agent that is not satisfactory because it liquefies at $24^{\circ}C$.

Agar-agar

A golden-yellow granular powder obtained from seaweed, used as a solidifying agent in concentrations of $1.5\text{--}2.0\%$.

Agar Properties

It is bacteriologically inert, remains solid at $37^{\circ}C$, and is transparent.

Synthetic (chemically defined) medium

A medium prepared from purified ingredients with a known exact chemical composition, providing specific carbon and nitrogen sources.

Peptone water

A simple medium consisting of $1\%$ peptone and $0.5\%$ $NaCl$ in water.

Simple media

General-purpose media such as Nutrient broth and Nutrient agar used to isolate colonies for morphology and pigmentation studies.

Nutrient agar composition

A mixture of Nutrient broth and $2\%$ agar.

Nutrient broth composition

A medium consisting of peptone, meat extract, $NaCl$, and water.

Complex media

Media containing natural ingredients like yeast extract, blood, or milk, where the exact chemical composition is not precisely known.

Fastidious organisms

Microorganisms with complex nutritional requirements that are supported by the rich nutrient content of complex media.

Examples of Complex media

Nutrient Agar, Nutrient Broth, Blood Agar, Chocolate Agar, MacConkey Agar, and Luria-Bertani (LB) Broth.

Special media classifications

Includes Enriched, Enrichment, Selective, Indicator, Differential, Sugar, Transport, and Media for biochemical reactions.

Aerobic and Anaerobic media

Media classified based on the oxygen requirements of the bacteria being cultured.