Bacto Proteose Peptone No. 2 is member of the Bacto Proteose Peptones, which are enzymatic digests of protein. Studies of peptic digests of animal tissue prepared under varying digestion parameters demonstrated that no single peptone is the most suitable nitrogen source for every microbiological application. These findings led to the development of Bacto Proteose Peptone, Bacto Proteose Peptone No. 2, and Bacto Proteose Peptone No. 3. Bacto Proteose Peptone No. 4 is a spray-dried version of Bacto Proteose Peptone.nn• Bacto Proteose Peptone is used in preparing microbiological culture media and in producing bacterial toxinsn• Bacto Proteose Peptone No. 2 is used in preparing microbiological culture median• Bacto Proteose Peptone No. 3 is used in preparing microbiological and mammalian cell culture median• Bacto Proteose Peptone No. 4 is a spray-dried version of Bacto Proteose Peptone. It offers the same beneficial nutrients as Bacto Proteose Peptone for growth promotion and toxin production in a wide range of fastidious microorganisms.