The invention relates to a nucleic acid molecule selected from the group comprising a) a nucleic acid molecule having one of the nucleotide sequences presented in SEQ ID:NO 4 to SEQ ID:NO 8, b) a nucleic acid molecule that codes for a peptide having one of the amino acid sequences presented in SEQ ID:NO 12 to SEQ ID:NO 16, c) a nucleic acid molecule, the complementary strand of which hybridizes to a nucleic acid molecule according to a) or b) and which codes for a peptide having antimicrobial activity, and d) a nucleic acid molecule, the nucleotide sequence of which deviates from the nucleotide sequence of a nucleic acid molecule according to c) because of the degenerated genetic code.