The two parts from iGEM13 DTU-Denmark, BBa_K1067002 and BBa_K1067004, are protein coding sequences extracted from the genome of Nitrosomonas europaea that code for nitrification enzymes: hydroxylamine oxidoreductase and cytochrome cycA&X. The homolog developed by DTU-Denmark used what we believed to be an improper coding sequence for a one of the subunits, HAO-B. HAO-B is a putative protein, that at the time may not have been believed to be significant. However, after reviewing the sequence registered in the BLAST database, we believed that HAO-B played a fundamental role in the mechanism of HAO. Since the two parts work hand in hand to nitrify ammonium, we improved the parts from DTU-Denmark by combining the two parts, inserting conditionally inducible promoters, and using signal peptides to transport the enzymes to their designated location in the cell.