Difference Between Culture and Media in Microbiology

The key difference between culture and media in microbiology is that culture in microbiology is a method of growing and maintaining microorganisms in vitro for different analysis while media in microbiology are solid or liquid formulations which contain nutrients and other necessary materials to support the growth of microorganisms and cells.

Microorganisms are tiny organisms that are not visible to our naked eye. They can be seen only under the microscope. They have different growth requirements and nutrients. If we want to grow them in our laboratories (in vitro) to study them and understand their processes, we need to provide them with all the growth requirements through a medium. Generally, a medium contains everything needed for the growth of a particular microorganism under laboratory conditions. Different types of media are used in microbiology. When a medium is inoculated with a microorganism, microbe grows inside the medium and becomes a culture of microorganism. Likewise, microbial cultures are prepared and maintained under laboratory conditions for different purposes such as storage, testing and chemical purification, etc.

CONTENTS

1. Overview and Key Difference
2. What is Culture in Microbiology
3. What is Media in Microbiology
4. Similarities Between Culture and Media in Microbiology
5. Side by Side Comparison – Culture vs Media in Microbiology in Tabular Form
6. Summary

What is a Culture in Microbiology?

Culture in microbiology or microbial culture is a method of culturing and maintaining microorganisms under laboratory conditions for different purposes. Cultures are grown in solid, semi-solid and liquid media based on the type and the purpose of the microorganism culturing. Cultures are provided with the necessary nutrients and growth conditions required by the microorganisms.

There are different types of microbial cultures such as batch culture, continuous culture, stab culture, agar plate culture and broth culture, etc. Microbial cultures are prepared under sterile conditions inside a special chamber called laminar airflow. Growing medium and glassware are sterilized prior to inoculation of the desired microorganism. Under proper sterile conditions, target microorganism is transferred into the sterilized nutrient medium and incubated at optimum temperature. Inside the medium, microorganism grows and multiplies, increasing its population by using the provided nutrients.

What is Media in Microbiology?

Growth medium or culture medium is a liquid, semi-solid or solid substrate designed for the growth of microorganisms under in vitro conditions. The medium contains all the necessary nutrients and conditions required for the multiplication of microorganisms. In fact, it is an artificial environment that supports the growth of the microbe. Selecting an appropriate growth medium is of utmost importance for the in vitro cultivation. Basal media and complete media are two types of growth media. Basal media or simple media are growth media that support the growth of non-fastidious bacteria. They are also called general purpose media. Complete media are the culture media enriched with all the growth requirements of an organism. Hence, a complete media consists of basal medium and other supplements.

Nutrient agar is a general-purpose medium used to grow bacterial species. It supports the growth of non-fastidious microorganisms. It contains several ingredients, including a nitrogen source, proteins source, water, NaCl, etc. Nutrient agar is routinely prepared in microbiology laboratories to grow bacteria for isolation, characterization, identification, DNA isolation, etc. Nutrient agar is also used to maintain bacterial cultures in the labs. The nutrient liquid medium does not contain agar. Therefore, the solid media are designed with a solidifying agent. Liquid media, on the other hand, do not possess a solidifying agent. Solid media is generally poured into Petri dishes and prepared agar plates. An agar plate provides a good surface and space to aerobic microorganisms, especially bacteria and fungi, to grow well. Liquid media are a type of culture media used to cultivate and maintain microorganisms. These are also referred to as culture broths. Liquid media remain as liquids even at the room temperature. Liquid media are generally poured into test tubes or culture bottles.

What are the Similarities Between Culture and Media in Microbiology?

• Microorganisms are grown on culture media.
• Both culture and media are two related things in microbiology.
• They are prepared under in vitro conditions.

What is the Difference Between Culture and Media in Microbiology?

Microbial culture is a method of growing and maintaining microorganisms under laboratory conditions. Media are the liquid, semi-solid or solid substrate designed for the growth of microorganisms under in vitro conditions. So, this is the key difference between culture and media in microbiology. There are different types of cultures – like batch culture, continuous culture, stab culture, agar plate culture, broth culture, etc. Meanwhile, the media can be solid, semi-solid or liquid media.

Below is a summary of the difference between culture and media in microbiology.

Summary – Culture vs Media in Microbiology

Microbial culture is a method of growing microorganism in the laboratory. It allows multiplication of microorganisms for different purposes such as chemical and pathogenicity testing, identification, production of useful compounds, etc. Microorganisms will grow and multiply inside the culture media. Cultures will contain millions of microorganisms. Meanwhile, the media are prepared for growing microorganisms in the lab. Media contain nutrients and other necessary growth requirements. They can be solid, semi-solid or liquid media. Thus, this is the summary of the difference between culture and media in microbiology.

Reference:

1.“Microbial Culture Methods.” Lumen, Available here.
2. “Growth Medium.” Wikipedia, Wikimedia Foundation, 4 Jan. 2021, Available here.

Image Courtesy:

1. “Culture of soil fungus Thanatephorus cucumeris (anamorphic Rhizoctonia solani)” By Tashkoskip – Own work, (CC BY-SA 4.0) via Commons Wikimedia

2. “Agar plate with colonies” By NOAA ocean explorer (Public Domain) via Commons Wikimedia