Physical and Chemical Properties | Keratinase is produced by microorganisms under the condition of keratin induction. The structure, activity, substrate specificity and enzyme activity of keratinase are also different for different strains. The main difference between keratinase and other proteolytic enzymes is that it binds more closely to the substrate and is more suitable. According to its active group, keratinase can be divided into serine protease, aspartic protease, and metalloproteinase; according to the composition of subunits, it can be divided into monomeric enzymes and complex enzymes; according to temperature and acid-base properties, It can be divided into acidic, neutral and alkaline keratinase; according to the secretion situation, it can be divided into intracellular enzymes and extracellular enzymes. The optimum reaction temperature of keratinase is generally 35 ℃-75 ℃, and most of them are concentrated in 45 ℃-55 ℃. The optimum pH range for keratinases derived from bacteria, fungi, and actinomycetes is generally between neutral and alkaline. There are many factors that affect the activity of keratinase, such as Ca2 and Mg2, which usually promote the activity of keratinase. Therefore, an appropriate amount of addition in the fermentation medium may help the production of keratinase; Phosphate, mercaptoethanol, vitamin C, etc. can also enhance the activity of keratinase from most bacteria. It may be because mercaptoethanol helps to break the disulfide bond and improve the enzymatic hydrolysis ability of keratinase. |