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Bacterial adhesion involves the attachment (or deposition) of bacteria on the surface (solid, gel layer, etc.). This interaction plays an important role in natural system as well as in environmental engineering. The attachment of biomass on the membrane surface will result in membrane fouling, which can significantly reduce the efficiency of the treatment system using membrane filtration process in wastewater treatment plants.〔Alexis J. de Kerchove and Menachem Elimelech, Impact of Alginate Conditioning Film on Deposition Kinetics of Motile and Nonmotile Pseudomonas aeruginosa Strains, Applied and Environmental Microbiology, Aug. 2007, p. 5227–5234.〕 The low adhesion of bacteria to soil is essential key for the success of in-situ bioremediation in groundwater treatment.〔Jeremy A. Redman, Sharon L. Walker and Menachem Elimelech, Bacterial adhesion and transport in porous media: role of the secondary energy minimum, Environ. Sci. Technol. 2004, 38, 1777-1785.〕 However, the contamination of pathogens in drinking water could be linked to the transportation of microorganisms in groundwater and other water sources.〔Alexis J. de Kerchove, Paweł Weronski, and Menachem Elimelech, Adhesion of Nonmotile Pseudomonas aeruginosa on “Soft” Polyelectrolyte Layer in a Radial Stagnation Point Flow System: Measurements and Model Predictions, Langmuir 2007, 23, 12301-12308.〕 Controlling and preventing the adverse impact of the bacterial deposition on the aquatic environment need a deeply understanding about the mechanisms of this process. DLVO theory has been used extensively to describe the deposition of bacteria in many current researches.〔〔〔〔Zachary A. Kuznar and Menachem Elimelech, Adhesion kinetics of Viable Cryptosporidium parvum Oocysts to Quartz Surfaces, Environ. Sci. Technol. 2004, 38, 6839-6845.〕〔Alexis J. de Kerchove and Menachem Elimelech, Calcium and Magnesium Cations Enhance the Adhesion of Motile and Nonmotile Pseudomonas aeruginosa on Alginate Films, Langmuir 2008, 24, 3392-3399.〕〔Sharon L. Walker, Jeremy A. Redman, and Menachem Elimelech, Role of Cell Surface Lipopolysaccharides in Escherichia coli K12 Adhesion and Transport, Langmuir 2004, 20, 7736-7746.〕 ==Prediction of bacterial deposition by classical DLVO theory== DLVO theory describes the interaction potential between charged surfaces. It is the sum of electrostatic double layer, which can be either attractive of repulsive, and attractive Van der Waals interactions of the charge surfaces.〔 DLVO theory is applied widely in explaining the aggregation and deposition of colloidal and nano particles such as Fullerene C60 in aquatic system. Because bacteria and colloid particles both share the similarities in size and surface charge, the deposition of bacteria also can be describe by the DLVO theory.〔〔〔〔 The prediction is based on sphere-plate interaction for one cell and the surface. The electrostatic double layer interactions could be describes by the expression for the constant surface potential 〔〔〔〔 Where ε0is the vacuum permittivity, εr is the relative dielectric permittivity of water, ap is the equivalent spherical radius of the bacteria, κ is the inverse of Debye length, h is the separation distance between the bacterium and the collector surface; ψp and ψc are the surface potentials of the bacterial cell and the collector surface. Zeta potential at the surface of the bacteria and the collector were used instead of the surface potential. The retarded Van der Waals interaction potential was calculated using the expression from Gregory, 1981 .〔〔〔〔 With A is Hamaker constant for bacteria-water-surface collector (quartz) = 6.5 x 10−21 J and λ is the characteristic wavelength of the dielectric and could be assumed 100 nm, a is the equivalent radius of the bacteria, h is the separation distance from the surface collector to the bacteria. Thus, the total interaction between bacteria and charged surface can be expressed as follow 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Bacterial adhesion in aquatic system」の詳細全文を読む スポンサード リンク
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