Chlorate and perchlorate pollutions have become a problem in the environment in the last decades. Studies have shown that some bacteria can degrade these substances into unharmful substances such as chloride and molecular oxygen. One of these chlorate degrading bacteria is Ideonella dechloratans that uses chlorate reductase and chlorite dismutase to process chlorate. In the promoter gene sequence of chlorite dismutase there might be regulator sequences such as fumarate and nitrate reductase regulator (FNR) and aerobic respiration control protein (ArcA) that might control the transcription of this enzyme. This promoter sequence was placed in a pBBR1MCS-4-LacZ reporter vector and the possible regulatory sequences were changed through site-directed mutagenesis and tested on activity through beta-galactosidase assays. The changes in the FNR binding sequence gave beta-galactosidase activity that was close to a negative control which might give conclusions that either FNR has an important role or an important part of the promoter was hit. The changes in the ArcA regulator binding sequence did not give such big differences and no certainty can be given if this made important changes to the promoter.