Final answer:
Vitamin B1, or thiamine, is the organic growth factor listed in the options provided. It is essential for the metabolic processes of organisms which cannot synthesize it internally.
Step-by-step explanation:
The organic growth factor in the options provided is vitamin B1. Growth factors are compounds required by certain organisms for growth that cannot be synthesized by the organism and must be obtained from the environment. Vitamin B1, also known as thiamine, is an essential nutrient that acts as a cofactor for enzymes involved in metabolic processes. Other options such as glucose, NH₄H₂PO₄ (ammonium phosphate), peptone, and H₂O do not fall into the category of growth factors as they either represent energy sources, nitrogen sources, or media supplements, rather than growth-required vitamins or coenzymes.
With respect to the reference information provided:
- The water-soluble vitamin is vitamin C.
- Water is not one of the four major classes of organic compounds.
- Pyruvate is not a commercially important fermentation product.
- Phosphorus is a macronutrient needed by prokaryotes.
- Phosphorus is also a nutrient stored in the body and is part of carbohydrates, proteins, and nucleic acids.