Industrial enzymes are often immobilized to improve their stability and allow for continuous reuse. There are two main types of reactor systems used - stirred tank reactors and continuous flow reactors. Stirred tank reactors involve stirring the immobilized enzyme with substrate in a batch process. Continuous flow reactors pass substrate through a column of immobilized enzyme in a continuous process. Immobilization can shift pH and temperature optima and improve stability. Important industrial applications of immobilized enzymes include high fructose corn syrup production using glucose isomerase and hydrolysis of lactose using beta-galactosidase.