What Must Be Added to M9 Medium for a Prototrophic

Question

What must be added to M9 medium for a prototrophic E.coli strain to be able to grow?
A)glucose
B)glucose plus nucleotides,amino acids and lipids
C)glucose plus at least one other organic component
D)glucose plus amino acids
E)the medium is sufficient

Accepted Answer

M9 medium contains only inorganic salts, so to support the growth of a prototrophic E.coli strain (which can synthesize its own nucleotides, amino acids and lipids), an additional organic component must be added to the medium. Glucose is commonly added as a carbohydrate source, but at least one other organic component is needed to meet the nutritional requirements of the bacteria. Therefore, choice C is the best option.