Growth media

By Levi Clancy for Student Reader on
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Minimal media consists of merely a carbon source and trace elements (P, S, K, Mg, Ca, Na). Iron is used for cellular respiration. N2 is used for N-fixing bacteria. Growth factors needed n small amounts: vitamins, amino acids, purines and pyrimidines.

MediaOverview

Simple Media

Contains precise amounts of highly purified organic and/or inorganic chemicals. For example, simple media might contain a single (or none) carbon source as well as mineral sources of nitrogen and sulfur. An organism growing in such a simple media could be cultivated from sand or other meager environment.

Complex

Precise chemical composition is unknown. Complex media typically include all amino acids, vitamins, purines and pyrimidines (these are all usually extracted from yeast, meat or milk). Organisms growing on complex media without sugar use amino acids for energy and biosynthesis, typically creating foul odors in the process. Organisms necessitating complex media with sugar perform glycolysis.

Differential

Differential media is an indicator media used for screening -- meaning dyes are added to the media to identify certain microbes.

Enriched

Complex media with additional nutrients like blood. Enriched media is useful for isolating organisms from a body.