Regulatory small RNAs (sRNAs) function as regulators of gene-expression on the post-transcriptional level. Hence, use of sRNAs would allow to implement an additional layer to control gene expression in addition to the classical use of inducible promoters. The goal of the project is the design of artificial sRNAs, the proof of this concept and the application of these regulators to improve the production of different target proteins with regard to quality and quantity.