This is the again one of the key tools for industrial biotechnology. Using a wild-type enzyme which is discovered in nature is not acceptable for an industrial process. It has to be engineered and optimized in terms of activity, selectivity, and stability. Some enzymes may have a high demand for industrial use, but due to its chemical properties it may loose its importance. Therefore these enzymes are modified so that it can withstand harsh conditions. These properties will comprise to maximize the yield.