Product formation type 1, 2 and 3

The document classifies fermentation into three types based on product formation related to growth and energy metabolism: type I, type II, and type III. Type I fermentation produces products directly from primary metabolism alongside growth, while type II fermentation synthesizes products from substrates with separate growth and product phases, exemplified by amino acids and citric acid. Type III fermentation distinctly separates growth and product formation phases, with primary substrate consumption occurring first and product formation following, as seen in antibiotic production.