GROWTH FACTORS OF MICROORGANISMS

GROWTH FACTORS 

• Growth factors are required in small amounts by bacterial cells to fulfill specific roles in biosynthesis. 
• Growth factors are Organic compounds (Purines, Pyrimidines, Amino acids and Vitamins) that a cell must have for growth but cannot synthesize itself. 
• Growth factors are organized into three categories. 1) Purines and Pyrimidines - Required for synthesis of Nucleic acids (DNA and RNA) 2) Amino acids - Required for the synthesis of Proteins 3) Vitamins - Needed as Coenzymes and functional groups of certain Enzymes 
• Some bacteria (e.g. Escherichia coli) do not require any Growth factors. They can synthesize all essential Purines, Pyrimidines, Amino acids and Vitamins, starting with their Carbon source, as part of their own intermediary metabolism. 
• Certain other bacteria (e.g. Lactobacillus) require Purines, Pyrimidines, Vitamins and several Amino acids in order to grow. These compounds must be added in advance to Culture media that are used to grow these bacteria.
• Microorganisms having complex nutritional requirements and needing many Growth factors are said to be Fastidious microorganisms.

Growth Factors of Microorganisms and their uses