Design of inducible expression vectors for improved protein production in Ralstonia eutropha H16 derived host strains

Ralstonia eutropha H16 (Cupriavidus necator H16) is a Gram-negative, facultative chemolithoautotrophic bacterium which can use H2 and CO2 as sole energy and carbon sources in the absence of organic substrates. The biotechnological use of R. eutropha H16 on an industrial scale has already been established; however, only a small number of tools promoting inducible gene expression is available. Within this study two systems promoting inducible expression were designed on the basis of the strong j5 promoter and the Escherichia coli lacI or the Pseudomonas putida cumate regulatory elements. Both expression vectors display desired regulatory features and further increase the number of suitable inducible expression systems for the production of metabolites and proteins with R. eutropha H16.