The organohalide respiration (OHR) is an important pathway for bioremidiation of halogenated anaerobic habitats. Dehalococcoides mccartyi strains are key players in that microbiological process. Reductive dehalogenases (Rdhs) reduces halogenated compounds. Strain CBDB1 encodes 32 genes for Rdhs, the rdhAB genes, but how they are regulated is unknown untill now. The most rdhAB genes are in vicinity to genes of MarR regulators or two component systems. In this thesis the regulation of rdhAB genes by MarR regulators RdhR1456, -1625 and -1596 was analysed. Heterologous in vivo studies in Escherichia coli revealed RdhR1456, -1625 and -1596 as repressors of associated rdhAB genes. In vitro research exhibited the interaction site of RdhR1456. A purified RdhR1456StrepC protein formed a dimeric structure in solution, but bound as a tetramer to the target DNA. In vivo analysis of all MarR regulators of CBDB1 brings out the complexity of the regulation of OHR in CBDB1. Different MarRs affect the transcription of different rdhA or rdhR genes. This dissertation gives new insight into the regulation of OHR, while MarR regulators play an important role.