Decomposition of Chlorinated Hydrocarbons Using the Biocatalyst Immobilized by Clay Minerals

Abstract:

Biochemical decomposition of catechol and 4-chlorocatechol, degradation intermediate products of 4-chlorophenol, was investigated using enzymes and their immobilized forms by clay minerals. An oxygenase that can initiate oxidative ring-fission of aromatic compounds was obtained via cloning of its gene (cphA-1) encoding hydroxyquinol dioxygenase contained in Arthrobacter chlorophenolicus A6 and overexpression and purification of the enzyme. The enzyme expressed in vitro was then immobilized onto the clay mineral (montmorillonite). Michaelis-Menten kinetic analysis was conducted to compare the expressed enzymes and the immobilized biocatalysts with regard to their degradation activity and capability to sustain activities under severe environments. Vmax values for the immobilized enzymes were smaller than those for the originally cloned enzymes, indicating that loss of enzyme activity was accompanied in the enzyme immobilization process. However, the immobilized enzyme demonstrated far more stable degrading activity in response to wide environmental changes such as marked variation of pH, temperature, and ionic strength. This supported that the enzyme immobilization can provide great advantages for its field application and also should be useful for establishing the concept of ecological green U-City.

• Periodical: Advanced Materials Research (Volumes 356-360)
• Pages: 1089-1092
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.356-360.1089
• Online since: October 2011
• Authors: Sun Hyung Lee, Ji Sook Lim, Han Seung Kim
• Keywords: Chlorinated Hydrocarbon, Clay Mineral, Enzyme, Immobilized Bio-catalyst

References

[1] S. Gan, E.V. Lau, and H.K. Ng, Remediation of soils contaminated with polycyclic aromatic hydrocarbons (PAHs), Journal of Hazardous Materials, Vol. 172 (2009), pp.532-549.

DOI: 10.1016/j.jhazmat.2009.07.118

[2] K. Nordin, M. Unell, and J.K. Jansson, Novel 4-chlorophenol degradation gene cluster and degradation route via hydroxyquinol in Arthrobacter chlorophenolicus A6, Applied and Environmental Microbiology, Vol. 71 (2005), p.6538–6544.

DOI: 10.1128/aem.71.11.6538-6544.2005

[3] K.S. Bhattacharya, Enzyme mixtures and complex biosynthesis, Landes Bioscience, Inc., Prance (2007).

[4] I. Alemzadeh, and S. Nejati, Phenols removal by immobilized horseradish peroxidase, Journal of Hazardous Materials, Vol. 166 (2009), pp.1082-1086.

DOI: 10.1016/j.jhazmat.2008.12.026

[5] W. Chouyyok, J. Panpranot, C. Thanachayanant, and S. Prichanont, Effects of pH and pore characters of mesoporous silicas on horseradish peroxidase immobilization, Journal of Molecular Catalysis B: Enzymatic, Vol. 56 (2009), pp.246-252.

DOI: 10.1016/j.molcatb.2008.05.009

[6] J.Z. Liu, H.Y. Song, L.P. Weng, and L.N. Ji, Increased thermostability and phenol removal efficiency by chemical modified horseradish peroxidase, Journal of Molecular Catalysis B: Enzymatic, Vol. 18 (2002), pp.225-232.

DOI: 10.1016/s1381-1177(02)00100-5