The invention relates to a method for generating a preparation of lipase with increased lipolytic activity comprising a step of altering one or more nucleotides in a polynucleotide comprising a first polynucleotide encoding a propeptide operationally linked to a second polynucleotide encoding a lipase, wherein the alteration of one or more nucleotides are made in the first polynucleotide and the alteration independently results in a substitution, an insertion or a deletion in the encoded propeptide amino acid sequence.