Enzyme plays an important role in many biological and industrial processes. As a result, several chemical industries are employing biocatalysts for its promising applications in molecular, regio and enantio-selectivity and ultimately economy. The organic reactions performed by the enzymes are enormous and being the first rate-limiting step in the iterative cycle of setting up bio catalytic process. Present, book discusses cloning and characterization of metagenomic lipase. In general, the lipolytic enzymes are produced by variety of organisms. Lipases obtained from microorganisms are industrially more important, as they are more stable towards harsh processes. The gene encoding lipase was amplified with degenerate set of primers and cloned. The cloned product was expressed, purified and characterized biophysically and biochemically. Furthermore, the book discuses the use of directed evolution of the lipase employing error prone PCR/site directed mutagenesis. A mutant developed by directed evolution is discussed and characterized biophysically/biochemically, the results were compared with the wild type protein.