Preparation of Ag/AgBr/TiO₂ as catalyst carriers and its damage to plasmid DNA and Tetrahymena

Abstract

The composites based on the TiO₂ are potentially used in wetland pollution control. In this work, the biological effect of the Ag/AgBr/TiO₂/Active carbon (AC) composites was studied on the plasmid DNA and Tetrahymena membrane. The atomic force micrograph (AFM) images showed that, in the presence of the composites under illumination, most pUC18 DNA molecules showed quite different topography and were opened and relaxed circle shapes. After DNA was catalyzed for 40 min, all supercoiled and circular DNA were changed into the linear DNA molecules. The gel electrophoresis experiment confirmed the results and demonstrated the dynamic process of DNA degradation. ATR-FTIR spectra revealed that amide groups and PO₂ ⁻ of the phospho-lipid phospho-diester on Tetrahymena surface were oxidized in the presence of the composites under illumination. An increase in the fluorescence polarization of DPH was observed, reflecting a significant decrease in membrane fluidity of Tetrahymena.

Keywords

TiO₂ / water treatment / Tetrahymena / plasmid DNA / wetland

References

[1] Anna G P, Masotti V, Höhener P, et al. Constructed Wetlands to Reduce Metal Pollution from Industrial Catchments in Aquatic Mediterranean Ecosystems: A Review to Overcome Obstacles and Suggest Potential Solutions[J]. Environment International, 2014, 64: 1-16.

[2] Zhang T, Xu D, He F, et al. Application of Constructed Wetland for Water Pollution Control in China During 1990-2010[J]. Ecological Engineering, 2012, 47: 189-197.

[3] Ham J, Yoon C G, Kim H J, et al. Modeling the Effects of Constructed Wetland on Nonpoint Source Pollution Control and Reservoir Water Quality Improvement[J]. Journal of Environmental Sciences, 2010, 22(6): 834-839.

[4] Zhang W W, Ma J Z. Waterbirds as Bioindicators of Wetland Heavy Metal Pollution[J]. Procedia Environmental Sciences, 2011, 10: 2769-2774.

[5] Guillard C, Bui T H, Felix C, et al. Microbiological Disinfection of Waterandair by Photocatalysis[J]. C. R. Chim., 2008, 11: 107-113.

[6] Sang X, Phan T G, Sugihara S, et al. Photocatalytic Inactivation of Diarrheal Viruses by Visible-light-catalytic Titanium Dioxide[J]. Clin. Lab., 2007, 53: 413-421.

[7] Lu Z X, Zhou L, Zhang Z L, et al. Cell Damage Induced by Photocatalysis of TiO₂ Thin Films[J]. Langmuir, 2003, 19: 8765-8768.

[8] Matsunaga T, Okochi M. TiO₂-mediated Photochemical Disinfection of E. coli Using Optical Fibers[J]. Environ. Sci. Technol., 1995, 29: 501-505.

[9] Ireland J C, Klostermann P, Rice E W, et al. Inactivation of Escherichia Coli by Titanium Dioxide Photocatalytic Oxidation[J]. Appl. Environ. Microbiol., 1993, 59: 1668-1670.

[10] Koide S, Nonami T. Disinfecting Efficacy of a Plastic Container Covered with Photocatalyst for Postharvest[J]. Food Control, 2007, 18: 1-4.

[11] Blake D M, Maness P C, Huang Z, et al. Application of the Photocatalytic Chemistry of Titanium Dioxide to Disinfection and the Killing of Cancer Cells[J]. Sep. Purif. Meth., 1999, 28: 1-50.

[12] Seo J W, Chung H, Kim M Y, et al. Development of Water-soluble Single-crystalline TiO2 Nanoparticles for Photocatalytic Cancer-cell Treatment[J]. Small, 2007, 3: 850-853.

[13] Ashikaga T, Wada M, Kobayashi H, et al. Effect of the Photocatalytic Activity of TiO₂ on Plasmid DNA[J]. Mutat. Res., 2000, 466: 1-7.

[14] Yang X D, Wang Y. Photocatalytic Effect on Plasmid DNA Damage under Different UV Irradiation Time[J]. Building Environ., 2008, 43: 253-257.

[15] Shen Y F. Modern Biomonitoring Techniques Using Freshwater Microbiota[M], 1990 Beijing: China Architecture and Building Press.

[16] Zhang Y H, Tang Z R, Fu X Z, et al. Nanocomposite of Ag-AgBr-TiO2 as a Photoactive and Durable Catalyst Fordegradation of Volatile Organic Compounds in the Gas Phase[J]. Applied Catalysis B: Environmental, 2011, 106: 445-452.

[17] Lu Z X, Zhang Z L, Zhang M X, et al. Core/shell Quantum-dotphotosensitized Nano-TiO₂ Films: Fabrication and Application to the Damage of Cells and DNA[J]. J. Phys. Chem. B, 2005, 109: 22663-22666.

[18] Thorme H V. Electrophoretic Separation of Polyoma Virus DNA from Host Cell DNA[J]. Virology, 1966, 29: 234-239.

[19] Kiwi J, Nadtochenko V. Evidence for the Mechanism of Photocatalytic Degradation of the Bacterial Wall Membrane at the TiO2 Interface by ATR-FTIR and Laser Kinetic Spectroscopy[J]. Langmuir, 2005, 21: 4631-4641.

[20] Hurjui I, Neamtu A, Dorohoi D O. The Interaction of Fluorescent DPH Probes with Unsaturated Phospholipid Membranes: A Molecular Dynamics Study[J]. Journal of Molecular Structure, 2013, 1044: 134-139.

[21] Liu P, Duan W, Wang Q, et al. The Envelope Damage of Tetrahymenain in the Presence of TiO₂ Combined with UV Light[J]. Photochemistry and Photobiology, 2010, 86: 633-638.

[22] Hauser H, Hinckley C C, Krebs J, et al. The Interaction of Ions with Phosphatidylcholine Bilayers[J]. Biochim. Biophys. Acta, 1977, 468(3): 364-377.

[23] Czogalla A, Grzybek M, Jones W, et al. Validity and Applicability of Membrane Model Systems for Studying Interactions of Peripheral Membrane Proteins with Lipids[J]. Biochimica et Biophysica Acta (BBA) -Molecular and Cell Biology of Lipids, 2014, 1841(8): 1049-1059.

[24] Sýkora J B L, Hof M, et al. The Effect of Detergents on Trimeric G-protein Activity in Isolated Plasma Membranes from Rat Brain Cortex: Correlation with Studies of DPH and Laurdan Fluorescence[J]. Biochimica et Biophysica Acta (BBA) -Biomembranes, 2009, 1788(2): 324-332.