199μg/ml·h;米氏常数Km=24。 3. Through the relation between the reaction rate and the concentration of substrate, the determinateMichaelis constantKm of the polyphenol oxidase (PPO) of barley was 1. 通过研究反应速率与底物浓度之间的关系,确定大麦多酚氧化酶(PPO)的米氏常数Km为1。