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Viruses as Nanomaterials
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Dushyant R. Dudhagara, Megha S. Gadhvi, Anjana K. Vala
Bacteriophage T4 is one of the most complex viruses. The mature virion, which consists of a protein shell encasing a 172 kbp double-stranded genomic DNA, a ‘tail’, and fibres connected to the distal end of the tail, is made up of more than 40 different proteins. The host cell recognition sensors are carried by the fibres and tail, which are necessary for phage attachment to the cell surface. The tail also acts as a conduit for phage DNA transmission from the head into the cytoplasm of the host cell. The tail is connected to the head's special ‘portal’ vertex, which is used to package phage DNA during head assembly. The unique vertex is dominated by a dodecameric portal protein, which is involved in DNA packaging, similar to other phages and herpes viruses (Leiman et al. 2003).
Fate of Wastewater Constituents in Soil and Groundwater: Pathogens
Published in G. Stuart Pettygrove, Takashi Asano, Irrigation With Reclaimed Municipal Wastewater–A Guidance Manual, 1985
The mobility of viruses in soil is related to the properties of the viral protein coat; to the cation exchange capacity, pH, hydraulic conductivity, surface area, organic matter content, and texture of the soil; and to the pH, the ionic strength, and the flow rate of the percolating fluid. Viruses are colloidal-size particles (10-300 nm) that possess a nucleic acid core encapsulated by a shell or capsid (sometimes the capsid is enclosed by an envelope). The morphological feature of the protein coat (which includes the capsid and lipoprotein envelope) is characterized by being amphoteric. Soil organic matter and clay are generally negatively charged and readily adsorb the positively charged reactive groups of the viral protein coat below its isoelectric point (the pH in which there is no electrical charge on the particle). Cookson [50, 51] studied the mechanism of adsorption of bacteriophage T4 to activated carbon and found that the adsorption process was reversible and obeyed linear adsorption isotherms. The mechanism of adsorption was believed to involve the positively charged amino groups of the T4 phage and the negatively charged carboxyl groups of the activated carbon particles. When the pH of the medium was lowered, the carboxyl groups became protonated and desorption was evident.
Practical Application of Ozone: Principles and Case Studies
Published in Bruno Langlais, David A. Reckhow, Deborah R. Brink, Ozone in Water Treatment, 2019
Guy Bablon, William D. Bellamy, Gilles Billen, Marie-Marguerite Bourbigot, F. Bernard Daniel, Françoise Erb, Cyril Gomella, Gilbert Gordon, Phillippe Hartemann, Jean-Claude Joret, William R. Knocke, Bruno Langlais, Alain Laplanche, Bernard Legube, Benjamin Lykins, Guy Martin, Nathalie Martin, Antoine Montiel, Marie Françoise Morin, Richard S. Miltner, Daniel Perrine, Michele Prévost, David A. Reckhow, Pierre Servais, Philip C. Singer, Otis J. Sproul, Claire Ventresque
The mechanism of ozone inactivation of bacteriophage £2 ribonucleic acid (RNA) studied by Kim et al. (1980) included releasing of RNA from the phage particles after the phage coat is broken into many protein subunit pieces. These findings suggest that ozone breaks the protein capsid, liberating RNA and disrupting adsorption to the host pili, and that the naked RNA may be secondarily inactivated by ozone but at a rate less than that for RNA within the intact phage. The mechanism of ozone inactivation of the deoxyribonucleic acid (DNA) bacteriophage T4 is quite similar: ozone attack of the protein capsid, liberation of the nucleic acid, and inactivation of the DNA by ozone (Sproul et al. 1982).
Application of clay ceramics and nanotechnology in water treatment: A review
Published in Cogent Engineering, 2018
Ebenezer Annan, Benjamin Agyei-Tuffour, Yaw Delali Bensah, David Sasu Konadu, Abu Yaya, Boateng Onwona-Agyeman, Emmanuel Nyankson
A mesoporous TiO2 has been investigated for their potential in deactivating E. coli. The high deactivation rate was attributed to the high surface area, small crystal size and more active site for deactivation (Liu, Wang, Yang, & Yang, 2008). The antimicrobial activity was enhanced after incorporating Ag into the TiO2 mesoporous structure. The improved antimicrobial activity was attributed to the improved photocatalysis and the fact that Ag has an antimicrobial property (Liu et al., 2008). The photocatalytic properties of TiO2 has been reported to be responsible for its antimicrobial activity (Kubacka et al., 2014). Irradiation of TiO2 with UV will result in the production of ROS or radicals which can attack bacteria, algae and fungi and result in their deactivation (Blake et al., 1999). By incorporating Fe3+ compounds such as Fe3(SO4)2, the antimicrobial efficiency is improved through the Fenton reaction (Cho, Chung, Choi, & Yoon, 2005). To aid in the easy separation of antimicrobial nanoparticles after application, a magnetic responsive nanocomposite nanoparticles made up of titania shell and nickel ferrite magnetic core has been synthesized using a combination of reverse micelle and hydrolysis processing techniques. The nickel ferrite-titania core-shell nanocomposite recorded an improved antibacterial efficiency (Rawat, Rana, Srivastava, & Misra, 2007). TiO2, CuO and TiO2/CuO antibacterial activity on E. coli and bacteriophage T4 has also been investigated (Ditta et al., 2008). The TiO2 recorded a lower microbial killing than CuO and TiO2/CuO. This trend was attributed to the generation of toxic Cu2+/Cu+ in the solution. The antimicrobial activity of TiO2 has been enhanced by combining it with biocidal polymer to form TiO2-biocidal polymer nanocomposite. A biocidal polymer is able to inhibit or kill microorganism. During UV irradiation, the TiO2/biocidal polymer showed improved inhibition of bacterial growth against gram-negative E. coli and gram-positive S. aureus in comparison to the pristine TiO2 nanoparticles (Kong, Song, & Jang, 2010).