increased sensitivity to chemical during vegetative growth sensitive to polypeptone midori sensitive to polypeptone during mitotic cell cycle sensitive to polypeptone during vegetative growth A phenotype observed in the vegetative growth phase of the life cycle in which cells show increased sensitivity to polypeptone. Cells stop growing (and may die) at a concentration of polypeptone that allows wild type cells to grow. Polypeptone is a mixture of peptones made up of equal parts of pancreatic digest of casein and peptic digest of animal used in media. hypersensitive to polypeptone FYPO:0002865 2013-11-14T12:31:56Z