The invention relates to five or four novel genes and the gene products thereof from Bacillus licheniformis and sufficiently similar genes and proteins which are involved in vivo in the formation of polyamino acids. The gene in question is ywsC, ywsC′, ywtA, ywtB and ywtD or proteins coded thereby. The gene ywsC, ywsC′, ywtA and ywtB can be used to improve biotechnological production methods by microorganisms, wherein they are functionally inactivated; the gene ywtD which codes for a peptide decomposing poly-gamma glutamate can, inversely, contribute to the improvement of biotechnological production methods by increased expression. Said genes can be used positively, preferably to result in a modification or decomposition of poly-gamma glutamate.