Dynamic Dispersal of Surface Layer Biofilm Induced by Nanosized TiO2 Based on Surface Plasmon Resonance and Waveguide

Peng Zhang; Jin-Song Guo; Peng Yan; You-Peng Chen; Wei Wang; You-Zhi Dai; Fang Fang; Gui-Xue Wang; Yu Shen

doi:10.1128/AEM.00047-18

Dynamic Dispersal of Surface Layer Biofilm Induced by Nanosized TiO₂ Based on Surface Plasmon Resonance and Waveguide

Appl Environ Microbiol. 2018 Apr 16;84(9):e00047-18. doi: 10.1128/AEM.00047-18. Print 2018 May 1.

Authors

Peng Zhang^{1

2}, Jin-Song Guo³, Peng Yan², You-Peng Chen^{4

2}, Wei Wang⁵, You-Zhi Dai¹, Fang Fang², Gui-Xue Wang⁶, Yu Shen⁷

Affiliations

¹ College of Environment and Resources, Xiangtan University, Xiangtan, China.
² Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing, China.
³ Key Laboratory of the Three Gorges Reservoir Region's Eco-Environments of MOE, Chongqing University, Chongqing, China guo0768@cqu.edu.cn ypchen@cqu.edu.cn.
⁴ College of Environment and Resources, Xiangtan University, Xiangtan, China guo0768@cqu.edu.cn ypchen@cqu.edu.cn.
⁵ School of Chemistry & Chemical Engineering, Nanjing University, Nanjing, China.
⁶ College of Bioengineering, Chongqing University, Chongqing, China.
⁷ National Base of International Science and Technology Cooperation for Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, China.

Abstract

Pollutant degradation is present mainly in the surface layer of biofilms, and the surface layer is the most vulnerable to impairment by toxic pollutants. In this work, the effects of nanosized TiO₂ (n-TiO₂) on the average thicknesses of Bacillus subtilis biofilm and on bacterial attachment on different surfaces were investigated. The binding mechanism of n-TiO₂ to the cell surface was also probed. The results revealed that n-TiO₂ caused biofilm dispersal and the thicknesses decreased by 2.0 to 2.6 μm after several hours of exposure. The attachment abilities of bacteria with extracellular polymeric substances (EPS) on hydrophilic surfaces were significantly reduced by 31% and 81% under 10 and 100 mg/liter of n-TiO₂, respectively, whereas those of bacteria without EPS were significantly reduced by 43% and 87%, respectively. The attachment abilities of bacteria with and without EPS on hydrophobic surfaces were significantly reduced by 50% and 56%, respectively, under 100 mg/liter of n-TiO₂ The results demonstrated that biofilm dispersal can be attributed to the changes in the cell surface structure and the reduction of microbial attachment ability.IMPORTANCE Nanoparticles can penetrate into the outer layer of biofilm in a relatively short period and can bind onto EPS and bacterial surfaces. The current work probed the effects of nanosized TiO₂ (n-TiO₂) on biofilm thickness, bacterial migration, and surface properties of the cell in the early stage using the surface plasmon resonance waveguide mode. The results demonstrated that n-TiO₂ decreased the adhesive ability of both cell and EPS and induced bacterial migration and biofilm detachment in several hours. The decreased adhesive ability of microbes and EPS worked against microbial aggregation, reducing the effluent quality in the biological wastewater treatment process.

Keywords: biofilm; extracellular polymeric substances; nanosized TiO2; surface plasmon resonance; waveguide.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bacillus subtilis / drug effects*
Bacillus subtilis / physiology*
Bacterial Adhesion
Biofilms / drug effects*
Extracellular Polymeric Substance Matrix / physiology
Hydrophobic and Hydrophilic Interactions
Metal Nanoparticles / analysis*
Surface Plasmon Resonance
Surface Properties
Titanium / analysis*

Substances

titanium dioxide
Titanium