Enriched Media: An enrichment medium contains some important growth factor (vitamin, amino acid, blood component, or carbon source) necessary for the growth of fastidious organisms. Selective Media: Selective media allow for the selection of particular microorganisms that may be present in a mixed culture. Selective media usually contain a component that enhances the growth of the desired organism or inhibits the growth of competing organisms.
Differential Media: Differential media allow for the separation of organisms based on some observable change in the appearance of the medium or by an observable effect on the microbe.
Complex Media: A complex medium is composed of a mixture of proteins and extracts in which the exact amount of a particular amino acid, sugar, or other nutrient is not known.
Synthetic Media: In a synthetic medium, the exact amount of pure chemicals used to formulate the medium is known.
B. Why is it necessary to use a solid agar medium to obtain a pure culture of S. epidermidis?
To obtain a pure culture, it is necessary to separate individual cells of a particular microbe. This requires the use of a solid medium that provides a surface for the individual cells to be separated and isolated from the other microbial cells that may be present in the original sample.
C. Compare your L. acidophilus pour plates and spread plate. Which method do you think worked better to isolate individual colonies? Why?
I think spread plates worked best because a solid medium that provides a surface for the individual cells to be separated and isolated from the other microbial cells that may be present in the original sample. Also the pour is more likely to gain unwanted bacteria through the dilution process.
D. What are the six qualities included in a description of colony morphology?
1. Shape: What is the basic formation of the colony? Is it circular, irregular, or