ABSTRACT
Enzymes are produced by all living cells as catalysts for specific chemical reactions. In food industry, enzyme has been used to produce and to increase the quality and the diversity of food. In the twentieth century, enzymes began to be isolated from living cells, which led to their large-scale commercial production and wider application in the food industry. Today, microorganisms are the most important source of commercial enzymes. Direct genetic modification encompasses the most precise methods for optimizing microorganisms for the production of enzymes. These methods are used to obtain high-yielding production organisms. The use of rennet, as an exogenous enzyme, in cheese manufacture is perhaps the largest single application of enzymes in food processing. Lactose can be obtained from various sources like plants, animal organs, bacteria, yeasts, or molds. Catalase is a form of protein. In fact, all enzymes are protein. Proteins are large globular molecules made of amino acid subunits.
