Team:SydneyUni Australia/Modelling Conclusion


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  • In our model we find that 1 mM of DCA is removed from solution within roughly 150 minutes when the DCA degrading cells are at a concentration of 2 x 108 cells/mL (graph 1 and graph 5).
  • It is also evident that bacterial growth can occur (graph 4, graph 8 and graph 9). This growth is due to the degradation of DCA to glycolate. We can also see that that bacterial growth correlates with glycolate accumulation (by comparing graph 6 and graph 9).
  • The cytotoxic metabolic intermediate chloroactealdehyde does not accumulate to a significant concentration in either of the pathways and is consistently at a negligibly low concentration. We can see that chloroacetaldehyde reaches a maximum concentration of roughly 0.2 mM in both pathways (graph 3 and graph 7). Chloroacetaldehyde is apparently metabolised very quickly; this concentration maximum is short lived, peaks at roughly 0.03 seconds and returns back to 0 mM by 0.5 seconds. It is expected that chloroacetaldehyde toxicity will not be a problem in our engineered cells.
  • We also conclude that the two pathways remove DCA at the same rate (by comparing graph 1 and graph 5).


[1] Krooshof, G. H., Ridder, I. S., Tepper, A. W., Vos, G. J., Rozeboom, H. J., Kalk, K. H., Dijkstra, B. W. & Janssen, D. B. (1998). Kinetic Analysis and X-ray Structure of Haloalkane Dehalogenase with a Modified Halide-Binding Site. Biochemistry, 37(43), 15013-15023.

[2] Janecki, D. J., Bemis, K. G., Tegeler, T. J., Sanghani, P. C., Zhai, L., Hurley, T. D., Bosron, W. F. & Wang, M. (2007). A multiple reaction monitoring method for absolute quantification of the human liver alcohol dehydrogenase ADH1C1 isoenzyme. Analytical Biochemistry, 369(1), 18-26.

[3] Pandey, A. V. & Flück, C. E. (2013). NADPH P450 oxidoreductase: Structure, function, and pathology of diseases. Pharmacology & Therapeutics, 138(2), 229-254.

[4] van der Ploeg, J., Shmidt, M. P., Landa, A. S., & Janssen, D. B. (1994). Identification of Chloroacetaldehyde Dehydrogenase Involved in 1,2-Dichloroethane Degradation. Applied Environmental Microbiology 60(5), 1599-1605.

[5] van der Ploeg, J., van Hall, G. & Janssen, D. B. (1991) Characterization of the haloacid dehalogenase from Xanthobacter autotrophicus GJ10 and sequencing of the dhlB gene. Journal of Bacteriology, 173(24), 7925-33.

[6] Sinensky, M. I. (1974). Homeoviscous Adaption – A Homeostatic Process that Regulates the Viscosity of Membrane Lipids in Escherichia coli. Proceedings from the National Academy of Science of the United States of America, 71(2), 522-525.

[7] CyberCell Database. Retrieved from

[8] Currie, R. C., Chiao, F. F., McKone, T. E. (1994) Intermedia Transfer Factors for Contaminants Found at Hazardous Waste Sites: 1,2 dichloroethane (DCA). Retrieved from

[9] Lord, J. M. (1972) Glycolate oxidoreductase in Escherichia coli. Biochemica et Biophysica Acta 267:2, 227-327.

[10] Ishihama, Y., Schmidt, T., Rappsilber, J., Mann, M., Hartl, F. U., Kerner, M. J. & Frishman, D. (2008) Protein abundance profiling of the Escherichia coli cytosol. BMC Genomics, 9:102.

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