The inventors have isolated novel lipolytic enzyme genes with a high homology to the T. lanuginosus lipase gene and thus well suited for use in gene shuffling. Accordingly, the invention provides a method of generating genetic diversity into lipolytic enzymes by family shuffling of two or more homologous genes which encode lipolytic enzymes. The DNA shuffling technique is used to create a library of shuffled genes, and this is expressed in a suitable expression system and the expressed proteins are screened for lipolytic enzyme activity. The invention also provides a polynucleotide comprising a nucleotide sequence encoding a lipolytic enzyme and a lipolytic enzyme (a polypeptide with lipolytic enzyme activity).