Nutrient content

- water: req ranking --> molds < yeasts < g+ < g- - energy source: sugars, alcohols, amino acids, complex carbohydrates - nitrogen sources: amino acids, nucleotides, peptides, proteins - vitamins & growth factors: many microbes req. B vitamins (g+ req more, g- can synthesize almost all req) - minerals: req. in small amounts (P, Ca, Mg, Fe, Mn, K)