Concept explainers
A certain medium has the following composition:
a. Tell what chemical category this medium belongs to, and explain why this is true.
b. How could you convert Staphylococcus medium (table 3.6A) into a nonsynthetic medium?
To analyze:
- The chemical category of the medium.
- Way of converting Staphylococcus medium into a nonsynthetic medium.
Introduction:
Culturing microorganisms out of their natural environments in pure form in the laboratory has been made possible only with the development of artificial medium or media. The role of media in the culture, identification, and mass production of microbes is remarkable. Based on the chemical composition there are two types of media: synthetic media with a chemically defined composition are used in research and cell culture and nonsynthetic, or complex, media with at least one component that is not chemically definable provide a rich mixture of nutrients for microbes with complex nutritional needs.
Explanation of Solution
- The medium mentioned here is a complex or nonsynthetic medium. The components yeast extract and peptone are complex organic compounds derived from yeasts and milk or meat. They cannot be chemically defined; hence, make the medium complex or nonsynthetic.
- The medium tabulated in table 3.6A is a synthetic medium with components that are chemically defined. The medium lists amino acids, vitamins, and salts in specific quantities, which can be replaced with organic compounds, to convert the medium into nonsynthetic medium. The brain-heart extract and peptone extract replace the dominant substances, however in unknown quantities, satisfying the specific nutrient requirements of Staphylococcus.
The medium in question is a complex or nonsynthetic medium that cannot be put into a single chemical class.
The medium in table 3.6 can be converted to a nonsynthetic medium by replacing the amino acids, vitamins, and salts with organic compounds and extracts (brain-heart extract) that will satisfy the nutrient needs of Staphylococcus.
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Chapter 3 Solutions
Foundations in Microbiology
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