1
|
Liu S, Quek SY, Huang K. An Ecofriendly Nature-Inspired Microcarrier for Enhancing Delivery, Stability, and Biocidal Efficacy of Phage-Based Biopesticides. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2403465. [PMID: 38940376 DOI: 10.1002/smll.202403465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/30/2024] [Indexed: 06/29/2024]
Abstract
In pursuit of sustainable agricultural production, the development of environmentally friendly and effective biopesticides is essential to improve food security and environmental sustainability. Bacteriophages, as emerging biocontrol agents, offer an alternative to conventional antibiotics and synthetic chemical pesticides. The primary challenges in applying phage-based biopesticides in agricultural settings are their inherent fragility and low biocidal efficacy, particularly the susceptibility to sunlight exposure. This study addresses the aforementioned challenges by innovatively encapsulating phages in sporopollenin exine capsules (SECs), which are derived from plant pollen grains. The size of the apertures on SECs could be controlled through a non-thermal and rapid process, combining reinflation and vacuum infusion techniques. This unique feature facilitates the high-efficiency encapsulation and controlled release of phages under various conditions. The proposed SECs could encapsulate over 9 log PFU g-1 of phages and significantly enhance the ultraviolet (UV) resistance of phages, thereby ensuring their enhanced survivability and antimicrobial efficacy. The effectiveness of SECs encapsulated phages (T7@SECs) in preventing and treating bacterial contamination on lettuce leaves is further demonstrated, highlighting the practical applicability of this novel biopesticide in field applications. Overall, this study exploits the potential of SECs in the development of phage-based biopesticides, presenting a promising strategy to enhancing agricultural sustainability.
Collapse
Affiliation(s)
- Shanshan Liu
- School of Chemical Sciences, The University of Auckland, Auckland, 1142, New Zealand
| | - Siew-Young Quek
- School of Chemical Sciences, The University of Auckland, Auckland, 1142, New Zealand
| | - Kang Huang
- Department of Biological Systems Engineering, Washington State University, Pullman, WA, 99164, USA
| |
Collapse
|
2
|
Leader A, Molad O, Dombrovsky A, Reches M, Mandler D. Interactions of Microorganisms with Lipid Langmuir Layers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:10340-10347. [PMID: 34461726 DOI: 10.1021/acs.langmuir.1c01431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Preventing microbial contamination of aquatic environments is crucial for the proper supply of drinking water. Hence, understanding the interactions that govern bacterial and virus adsorption to surfaces is crucial to prevent infection transmittance. Here, we describe a new approach for studying the organization and interactions of various microorganisms, namely, Escherichia coli (E. coli) bacteria, E. coli-specific bacteriophage T4, and plant cucumber green mottle mosaic viruses (CGMMV), at the air/water interface using the Langmuir-Blodgett (LB) technique. CGMMV were found as applicable candidates for further studying their interactions with Langmuir lipid monolayers. The zwitterionic, positively, and negatively charged LB lipid monolayers with adsorbed viruses were deposited onto solid supports and characterized by atomic force microscopy. Using polymerase chain reaction, we indicated that the adsorption of CGMMV onto the LB monolayer is a result of electrostatic interactions. These insights are useful in engineering membrane filters that prevent biofouling for efficient purification systems.
Collapse
Affiliation(s)
- Avia Leader
- Institute of Chemistry, The Hebrew University of Jerusalem, Israel Edmond Safra Campus, Jerusalem 9190401, Israel
| | - Ori Molad
- Institute of Chemistry, The Hebrew University of Jerusalem, Israel Edmond Safra Campus, Jerusalem 9190401, Israel
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, 68 HaMaccabim Road, P.O.B 15159 Rishon LeZion, Rishon LeZion 7505101, Israel
| | - Aviv Dombrovsky
- Department of Plant Pathology and Weed Research, Agricultural Research Organization, The Volcani Center, 68 HaMaccabim Road, P.O.B 15159 Rishon LeZion, Rishon LeZion 7505101, Israel
| | - Meital Reches
- Institute of Chemistry, The Hebrew University of Jerusalem, Israel Edmond Safra Campus, Jerusalem 9190401, Israel
| | - Daniel Mandler
- Institute of Chemistry, The Hebrew University of Jerusalem, Israel Edmond Safra Campus, Jerusalem 9190401, Israel
| |
Collapse
|
3
|
Abraham S, Kaufman Y, Perreault F, Young R, Bar-Zeev E. Bursting out: linking changes in nanotopography and biomechanical properties of biofilm-forming Escherichia coli to the T4 lytic cycle. NPJ Biofilms Microbiomes 2021; 7:26. [PMID: 33731698 PMCID: PMC7969764 DOI: 10.1038/s41522-021-00195-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 01/20/2021] [Indexed: 11/09/2022] Open
Abstract
The bacteriophage infection cycle has been extensively studied, yet little is known about the nanostructure and mechanical changes that lead to bacterial lysis. Here, atomic force microscopy was used to study in real time and in situ the impact of the canonical phage T4 on the nanotopography and biomechanics of irreversibly attached, biofilm-forming E. coli cells. The results show that in contrast to the lytic cycle in planktonic cells, which ends explosively, anchored cells that are in the process of forming a biofilm undergo a more gradual lysis, developing distinct nanoscale lesions (~300 nm in diameter) within the cell envelope. Furthermore, it is shown that the envelope rigidity and cell elasticity decrease (>50% and >40%, respectively) following T4 infection, a process likely linked to changes in the nanostructure of infected cells. These insights show that the well-established lytic pathway of planktonic cells may be significantly different from that of biofilm-forming cells. Elucidating the lysis paradigm of these cells may advance biofilm removal and phage therapeutics.
Collapse
Affiliation(s)
- Shiju Abraham
- Zuckerberg Institute for Water Research, The Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Yair Kaufman
- Zuckerberg Institute for Water Research, The Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boqer Campus, Midreshet Ben-Gurion, Israel.
| | - François Perreault
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA
| | - Ry Young
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Texas A&M AgriLife, College Station, TX, USA
| | - Edo Bar-Zeev
- Zuckerberg Institute for Water Research, The Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boqer Campus, Midreshet Ben-Gurion, Israel.
| |
Collapse
|
4
|
High-resolution imaging of the microbial cell surface. J Microbiol 2016; 54:703-708. [PMID: 27796933 DOI: 10.1007/s12275-016-6348-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/13/2016] [Accepted: 09/13/2016] [Indexed: 10/20/2022]
Abstract
Microorganisms, or microbes, can function as threatening pathogens that cause disease in humans, animals, and plants; however, they also act as litter decomposers in natural ecosystems. As the outermost barrier and interface with the environment, the microbial cell surface is crucial for cell-to-cell communication and is a potential target of chemotherapeutic agents. Surface ultrastructures of microbial cells have typically been observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Owing to its characteristics of low-temperature specimen preparation and superb resolution (down to 1 nm), cryo-field emission SEM has revealed paired rodlets, referred to as hydrophobins, on the cell walls of bacteria and fungi. Recent technological advances in AFM have enabled high-speed live cell imaging in liquid at the nanoscale level, leading to clear visualization of cell-drug interactions. Platinum-carbon replicas from freeze-fractured fungal spores have been observed using transmission electron microscopy, revealing hydrophobins with varying dimensions. In addition, AFM has been used to resolve bacteriophages in their free state and during infection of bacterial cells. Various microscopy techniques with enhanced spatial resolution, imaging speed, and versatile specimen preparation are being used to document cellular structures and events, thus addressing unanswered biological questions.
Collapse
|
5
|
Kämmer E, Götz I, Bocklitz T, Stöckel S, Dellith A, Cialla-May D, Weber K, Zell R, Dellith J, Deckert V, Popp J. Single particle analysis of herpes simplex virus: comparing the dimensions of one and the same virions via atomic force and scanning electron microscopy. Anal Bioanal Chem 2016; 408:4035-41. [PMID: 27052775 DOI: 10.1007/s00216-016-9492-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/12/2016] [Accepted: 03/15/2016] [Indexed: 10/22/2022]
Abstract
Currently, two types of direct methods to characterize and identify single virions are available: electron microscopy (EM) and scanning probe techniques, especially atomic force microscopy (AFM). AFM in particular provides morphologic information even of the ultrastructure of viral specimens without the need to cultivate the virus and to invasively alter the sample prior to the measurements. Thus, AFM can play a critical role as a frontline method in diagnostic virology. Interestingly, varying morphological parameters for virions of the same type can be found in the literature, depending on whether AFM or EM was employed and according to the respective experimental conditions during the AFM measurements. Here, an inter-methodological proof of principle is presented, in which the same single virions of herpes simplex virus 1 were probed by AFM previously and after they were measured by scanning electron microscopy (SEM). Sophisticated chemometric analyses then allowed a calculation of morphological parameters of the ensemble of single virions and a comparison thereof. A distinct decrease in the virions' dimensions was found during as well as after the SEM analyses and could be attributed to the sample preparation for the SEM measurements. Graphical abstract The herpes simplex virus is investigated with scanning electron and atomic force microscopy in view of varying dimensions.
Collapse
Affiliation(s)
- Evelyn Kämmer
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany.,InfectoGnostics Forschungscampus Jena e.V., Zentrum für Angewandte Forschung, Philosophenweg 7, 07743, Jena, Germany
| | - Isabell Götz
- Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany.,InfectoGnostics Forschungscampus Jena e.V., Zentrum für Angewandte Forschung, Philosophenweg 7, 07743, Jena, Germany
| | - Thomas Bocklitz
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany. .,Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany. .,InfectoGnostics Forschungscampus Jena e.V., Zentrum für Angewandte Forschung, Philosophenweg 7, 07743, Jena, Germany.
| | - Stephan Stöckel
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,InfectoGnostics Forschungscampus Jena e.V., Zentrum für Angewandte Forschung, Philosophenweg 7, 07743, Jena, Germany
| | - Andrea Dellith
- Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany
| | - Dana Cialla-May
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany.,InfectoGnostics Forschungscampus Jena e.V., Zentrum für Angewandte Forschung, Philosophenweg 7, 07743, Jena, Germany
| | - Karina Weber
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany.,InfectoGnostics Forschungscampus Jena e.V., Zentrum für Angewandte Forschung, Philosophenweg 7, 07743, Jena, Germany
| | - Roland Zell
- Department of Virology and Antiviral Therapy, Jena University Hospital, Friedrich Schiller University Jena, Hans-Knöll-Str. 2, 07745, Jena, Germany
| | - Jan Dellith
- Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany
| | - Volker Deckert
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany.,InfectoGnostics Forschungscampus Jena e.V., Zentrum für Angewandte Forschung, Philosophenweg 7, 07743, Jena, Germany
| | - Jürgen Popp
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.,Leibniz Institute of Photonic Technology (IPHT), Albert-Einstein-Str. 9, 07745, Jena, Germany.,InfectoGnostics Forschungscampus Jena e.V., Zentrum für Angewandte Forschung, Philosophenweg 7, 07743, Jena, Germany
| |
Collapse
|
6
|
Li M, Li M, Lin H, Wang J, Jin Y, Han F. Characterization of the novel T4-like Salmonella enterica bacteriophage STP4-a and its endolysin. Arch Virol 2015; 161:377-84. [PMID: 26563319 DOI: 10.1007/s00705-015-2647-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 10/12/2015] [Indexed: 12/20/2022]
Abstract
While screening for new antimicrobial agents for multidrug-resistant Salmonella enterica, the novel lytic bacteriophage STP4-a was isolated and characterized. Phage morphology revealed that STP4-a belongs to the family Myoviridae. Bacterial challenge assays showed that different serovars of Salmonella enterica were susceptible to STP4-a infection. The genomic characteristics of STP4-a, containing 159,914 bp of dsDNA with an average GC content of 36.86 %, were determined. Furthermore, the endolysin of STP4-a was expressed and characterized. The novel endolysin, LysSTP4, has hydrolytic activity towards outer-membrane-permeabilized S. enterica and Escherichia coli. These results provide essential information for the development of novel phage-based biocontrol agents against S. enterica.
Collapse
Affiliation(s)
- Meng Li
- Food Safety Laboratory, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Mengzhe Li
- Food Safety Laboratory, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Hong Lin
- Food Safety Laboratory, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Jingxue Wang
- Food Safety Laboratory, Ocean University of China, Qingdao, 266003, People's Republic of China.
| | - Yanqiu Jin
- Food Safety Laboratory, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Feng Han
- Food Safety Laboratory, Ocean University of China, Qingdao, 266003, People's Republic of China
| |
Collapse
|
7
|
Nault L, Taofifenua C, Anne A, Chovin A, Demaille C, Besong-Ndika J, Cardinale D, Carette N, Michon T, Walter J. Electrochemical atomic force microscopy imaging of redox-immunomarked proteins on native potyviruses: from subparticle to single-protein resolution. ACS NANO 2015; 9:4911-4924. [PMID: 25905663 DOI: 10.1021/acsnano.5b00952] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We show herein that electrochemical atomic force microscopy (AFM-SECM), operated in molecule touching (Mt) mode and combined with redox immunomarking, enables the in situ mapping of the distribution of proteins on individual virus particles and makes localization of individual viral proteins possible. Acquisition of a topography image allows isolated virus particles to be identified and structurally characterized, while simultaneous acquisition of a current image allows the sought after protein, marked by redox antibodies, to be selectively located. We concomitantly show that Mt/AFM-SECM, due to its single-particle resolution, can also uniquely reveal the way redox functionalization endowed to viral particles is distributed both statistically among the viruses and spatially over individual virus particles. This possibility makes Mt/AFM-SECM a unique tool for viral nanotechnology.
Collapse
Affiliation(s)
- Laurent Nault
- †Laboratoire d'Electrochimie Moléculaire, Université Paris Diderot, Sorbonne Paris Cité, Unité Mixte de Recherche Université, CNRS No 7591, Bâtiment Lavoisier, 15 rue Jean-Antoine de Baïf, 75205 Cedex 13 Paris, France
| | - Cécilia Taofifenua
- †Laboratoire d'Electrochimie Moléculaire, Université Paris Diderot, Sorbonne Paris Cité, Unité Mixte de Recherche Université, CNRS No 7591, Bâtiment Lavoisier, 15 rue Jean-Antoine de Baïf, 75205 Cedex 13 Paris, France
| | - Agnès Anne
- †Laboratoire d'Electrochimie Moléculaire, Université Paris Diderot, Sorbonne Paris Cité, Unité Mixte de Recherche Université, CNRS No 7591, Bâtiment Lavoisier, 15 rue Jean-Antoine de Baïf, 75205 Cedex 13 Paris, France
| | - Arnaud Chovin
- †Laboratoire d'Electrochimie Moléculaire, Université Paris Diderot, Sorbonne Paris Cité, Unité Mixte de Recherche Université, CNRS No 7591, Bâtiment Lavoisier, 15 rue Jean-Antoine de Baïf, 75205 Cedex 13 Paris, France
| | - Christophe Demaille
- †Laboratoire d'Electrochimie Moléculaire, Université Paris Diderot, Sorbonne Paris Cité, Unité Mixte de Recherche Université, CNRS No 7591, Bâtiment Lavoisier, 15 rue Jean-Antoine de Baïf, 75205 Cedex 13 Paris, France
| | - Jane Besong-Ndika
- ‡UMR 1332 Biologie du Fruit et Pathologie, INRA-Université Bordeaux 2, 71 av. Edouard Bourlaux, 20032-33882 Cedex Villenave d'Ornon, France
- §Department of Food and Environmental Sciences, University of Helsinki, Latokartanonkaari 11, FI-00014 Helsinki, Finland
| | - Daniela Cardinale
- ‡UMR 1332 Biologie du Fruit et Pathologie, INRA-Université Bordeaux 2, 71 av. Edouard Bourlaux, 20032-33882 Cedex Villenave d'Ornon, France
| | - Noëlle Carette
- ‡UMR 1332 Biologie du Fruit et Pathologie, INRA-Université Bordeaux 2, 71 av. Edouard Bourlaux, 20032-33882 Cedex Villenave d'Ornon, France
| | - Thierry Michon
- ‡UMR 1332 Biologie du Fruit et Pathologie, INRA-Université Bordeaux 2, 71 av. Edouard Bourlaux, 20032-33882 Cedex Villenave d'Ornon, France
| | - Jocelyne Walter
- ‡UMR 1332 Biologie du Fruit et Pathologie, INRA-Université Bordeaux 2, 71 av. Edouard Bourlaux, 20032-33882 Cedex Villenave d'Ornon, France
| |
Collapse
|
8
|
Janež N, Loc-Carrillo C. Use of phages to control Campylobacter spp. J Microbiol Methods 2013; 95:68-75. [PMID: 23830848 DOI: 10.1016/j.mimet.2013.06.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 06/22/2013] [Accepted: 06/25/2013] [Indexed: 01/21/2023]
Abstract
The use of phages to control pathogenic bacteria has been investigated since they were first discovered in the beginning of the 1900s. Over the last century we have slowly gained an in-depth understanding of phage biology including which phage properties are desirable when considering phage as biocontrol agents and which phage characteristics to potentially avoid. Campylobacter infections are amongst the most frequently encountered foodborne bacterial infections around the world. Handling and consumption of raw or undercooked poultry products have been determined to be the main route of transmission. The ability to use phages to target these bacteria has been studied for more than a decade and although we have made progress towards deciphering how best to use phages to control Campylobacter associated with poultry production, there is still much work to be done. This review outlines methods to improve the isolation of these elusive phages, as well as methods to identify desirable characteristics needed for a successful outcome. It also highlights the body of research undertaken so far and what criteria to consider when doing in-vivo studies, especially because some in-vitro studies have not been found to translate into to phage efficacy in-vivo.
Collapse
Affiliation(s)
- Nika Janež
- Laboratory of Bio-Analytics, Center of Excellence for Biosensors, Instrumentation and Process Control, Solkan, Slovenia
| | | |
Collapse
|
9
|
Abstract
Since the advent of the electron microscope approximately 70 years ago, bacterial viruses and electron microscopy are inextricably linked. Electron microscopy proved that bacteriophages are particulate and viral in nature, are complex in size and shape, and have intracellular development cycles and assembly pathways. The principal contribution of electron microscopy to bacteriophage research is the technique of negative staining. Over 5500 bacterial viruses have so far been characterized by electron microscopy, making bacteriophages, at least on paper, the largest viral group in existence. Other notable contributions are cryoelectron microcopy and three-dimensional image reconstruction, particle counting, and immunoelectron microscopy. Scanning electron microscopy has had relatively little impact. Transmission electron microscopy has provided the basis for the recognition and establishment of bacteriophage families and is one of the essential criteria to classify novel viruses into families. It allows for instant diagnosis and is thus the fastest diagnostic technique in virology. The most recent major contribution of electron microscopy is the demonstration that the capsid of tailed phages is monophyletic in origin and that structural links exist between some bacteriophages and viruses of vertebrates and archaea. DNA sequencing cannot replace electron microscopy and vice versa.
Collapse
Affiliation(s)
- Hans-W Ackermann
- Department of Microbiology, Epidemiology and Infectiology, Faculty of Medicine, Laval University, Quebec, Canada
| |
Collapse
|
10
|
Soylemez E, de Boer MP, Sae-Ueng U, Evilevitch A, Stewart TA, Nyman M. Photocatalytic degradation of bacteriophages evidenced by atomic force microscopy. PLoS One 2013; 8:e53601. [PMID: 23301095 PMCID: PMC3536765 DOI: 10.1371/journal.pone.0053601] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Accepted: 11/30/2012] [Indexed: 11/19/2022] Open
Abstract
Methods to supply fresh water are becoming increasingly critical as the world population continues to grow. Small-diameter hazardous microbes such as viruses (20-100 nm diameter) can be filtered by size exclusion, but in this approach the filters are fouled. Thus, in our research, we are investigating an approach in which filters will be reusable. When exposed to ultraviolet (UV) illumination, titanate materials photocatalytically evolve (•)OH and O2(•-) radicals, which attack biological materials. In the proposed approach, titanate nanosheets are deposited on a substrate. Viruses adsorb on these nanosheets and degrade when exposed to UV light. Using atomic force microscopy (AFM), we image adsorbed viruses and demonstrate that they are removed by UV illumination in the presence of the nanosheets, but not in their absence.
Collapse
Affiliation(s)
- Emrecan Soylemez
- Mechanical Engineering Department, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Maarten P. de Boer
- Mechanical Engineering Department, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Udom Sae-Ueng
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Alex Evilevitch
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Tom A. Stewart
- Geochemistry, Sandia National Laboratories, Albuquerque, New Mexico, United States of America
| | - May Nyman
- Geochemistry, Sandia National Laboratories, Albuquerque, New Mexico, United States of America
| |
Collapse
|
11
|
Kuznetsov YG, Chang SC, Credaroli A, Martiny J, McPherson A. An atomic force microscopy investigation of cyanophage structure. Micron 2012; 43:1336-42. [PMID: 22424715 DOI: 10.1016/j.micron.2012.02.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 02/19/2012] [Accepted: 02/19/2012] [Indexed: 11/15/2022]
Abstract
Marine viruses have only relatively recently come to the attention of molecular biologists, and the extraordinary diversity of potential host organisms suggests a new wealth of genetic and structural forms. A promising technology for characterizing and describing the viruses structurally is atomic force microscopy (AFM). We provide examples here of some of the different architectures and novel structural features that emerge from even a very limited investigation, one focused on cyanophages, viruses that infect cyanobacteria (blue-green algae). These were isolated by phage selection of viruses collected from California coastal waters. We present AFM images of tailed, spherical, filamentous, rod shaped viruses, and others of eccentric form. Among the tailed phages numerous myoviruses were observed, some having long tail fibers, some other none, and some having no visible baseplate. Syphoviruses and a podovirus were also seen. We also describe a unique structural features found on some tailed marine phages that appear to have no terrestrial homolog. These are long, 450 nm, complex helical tail fibers terminating in a unique pattern of 3+1 globular units made up of about 20 small proteins.
Collapse
Affiliation(s)
- Yurii G Kuznetsov
- Department of Molecular Biology and Biochemistry, 560 Steinhaus Hall, University of California, Irvine, CA 92697-3900, United States
| | | | | | | | | |
Collapse
|