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Ghimire B, Pendyala B, Patras A, Baysal-Gurel F. Evaluating UV-C Sensitivity of Calonectria pseudonaviculata in Model Buffer Solution Using a UV-C Light-Emitting-Diode System. PLANT DISEASE 2024; 108:2663-2667. [PMID: 38720539 DOI: 10.1094/pdis-03-24-0618-sc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/29/2024]
Abstract
Calonectria pseudonaviculata, responsible for boxwood blight, produces sticky conidia that pose a contamination risk in boxwood production via cross-contamination from tools, equipment, and other resources. This study evaluated UV-C light-emitting-diode (LED) irradiation (263 to 287 nm) as a disinfection method by examining its effectiveness in inactivating conidia and determining the UV-C sensitivity. Conidial suspensions were exposed to quantifiable UV-C doses under a dynamic stirring condition. Average volumetric intensity was quantified by accounting for UV gradients and UV dose was calculated as a product of average fluence rate (mW⋅cm-2) and exposure time (s). UV-C irradiation effectively inactivated the tested pathogen following log-linear + shoulder kinetics as identified by parameters of goodness of model fit (i.e., high R2 and low root mean square error [RMSE] values). The model predicted the UV sensitivity of C. pseudonaviculata conidia as 46.6 mJ⋅cm-2 per log. A total of 2.04 log reductions of the population could be obtained by an exposure of 60 mJ⋅cm-2 of UV-C dose. The calculated decimal reduction dose (D10) was 13.53 ± 0.98 mJ⋅cm-2 (R2 = 0.97, RMSE = 0.14), inactivation rate constant (Kmax) = 0.17 ± 0.01, and shoulder length = 33.06 ± 1.81 mJ⋅cm-2. These findings indicate that UV-C irradiation could be a viable option for disinfecting tools, equipment, and possibly propagation cuttings in nurseries.
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Affiliation(s)
- Bhawana Ghimire
- Department of Agricultural Sciences and Engineering, College of Agriculture, Tennessee State University, Otis L. Floyd Nursery Research Center, McMinnville, TN 37110
| | - Brahmaiah Pendyala
- Department of Food and Animal Sciences, College of Agriculture, Tennessee State University, Nashville, TN 37209
| | - Ankit Patras
- Department of Food and Animal Sciences, College of Agriculture, Tennessee State University, Nashville, TN 37209
| | - Fulya Baysal-Gurel
- Department of Agricultural Sciences and Engineering, College of Agriculture, Tennessee State University, Otis L. Floyd Nursery Research Center, McMinnville, TN 37110
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2
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Zhang Z, Zhang H, Wu G, Xu X, Cao R, Wan Q, Xu H, Wang J, Huang T, Wen G. The aggregation characteristics of Aspergillus spores under various conditions and the impact on LPUV inactivation: Comparisons with chlorine-based disinfection. WATER RESEARCH 2024; 253:121323. [PMID: 38377927 DOI: 10.1016/j.watres.2024.121323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 01/30/2024] [Accepted: 02/14/2024] [Indexed: 02/22/2024]
Abstract
Aggregation is the primary step prior to fungal biofilm development. Understanding the attributes of aggregation is of great significance to better control the emergence of waterborne fungi. In this study, the aggregation of Aspergills spores (A. flavus and A. fumigatus) under various salt, culture medium, and humic acid (HA) conditions was investigated for the first time, and the inactivation via low-pressure ultraviolet (LPUV) upon aggregated Aspergillus spores was also presented. The aggregation efficiency and size of aggregates increased over time and at low salt (NaCl and CaCl2) concentration (10 mM) while decreasing with the continuous increase of salt concentration (100 and 200 mM). Increasing the concentration of culture medium and HA promoted the aggregation of fungal spores. Spores became hydrated, swelled, and secreted more viscous substances during the growth period, which accelerated the aggregation process. Results also suggested that fungal spores aggregated more easily in actual water, posing a high risk of biohazard in real-life scenarios. Inactivation efficiency by LPUV decreased with higher aggregation degrees due to the protection from the damaged spores on the outer layer and the shielding of pigments in the cell wall. Compared to chlorine-based disinfection, the aggregation resulted in the extension of shoulder length yet neglectable change of inactivation rate constant under LPUV treatment. Further investigation of cell membrane integrity and intracellular reactive oxygen species was conducted to elucidate the difference in mechanisms between various techniques. This study provides insight into the understanding and controlling of the aggregation of fungal spores.
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Affiliation(s)
- Zhenghong Zhang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Huan Zhang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Gehui Wu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Xiangqian Xu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Ruihua Cao
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Qiqi Wan
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Huining Xu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Jingyi Wang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Tinglin Huang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Gang Wen
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China.
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3
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Öberg R, Sil TB, Johansson AC, Malyshev D, Landström L, Johansson S, Andersson M, Andersson PO. UV-Induced Spectral and Morphological Changes in Bacterial Spores for Inactivation Assessment. J Phys Chem B 2024; 128:1638-1646. [PMID: 38326108 PMCID: PMC10895659 DOI: 10.1021/acs.jpcb.3c07062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/09/2024]
Abstract
The ability to detect and inactivate spore-forming bacteria is of significance within, for example, industrial, healthcare, and defense sectors. Not only are stringent protocols necessary for the inactivation of spores but robust procedures are also required to detect viable spores after an inactivation assay to evaluate the procedure's success. UV radiation is a standard procedure to inactivate spores. However, there is limited understanding regarding its impact on spores' spectral and morphological characteristics. A further insight into these UV-induced changes can significantly improve the design of spore decontamination procedures and verification assays. This work investigates the spectral and morphological changes to Bacillus thuringiensis spores after UV exposure. Using absorbance and fluorescence spectroscopy, we observe an exponential decay in the spectral intensity of amino acids and protein structures, as well as a logistic increase in dimerized DPA with increased UV exposure on bulk spore suspensions. Additionally, using micro-Raman spectroscopy, we observe DPA release and protein degradation with increased UV exposure. More specifically, the protein backbone's 1600-1700 cm-1 amide I band decays slower than other amino acid-based structures. Last, using electron microscopy and light scattering measurements, we observe shriveling of the spore bodies with increased UV radiation, alongside the leaking of core content and disruption of proteinaceous coat and exosporium layers. Overall, this work utilized spectroscopy and electron microscopy techniques to gain new understanding of UV-induced spore inactivation relating to spore degradation and CaDPA release. The study also identified spectroscopic indicators that can be used to determine spore viability after inactivation. These findings have practical applications in the development of new spore decontamination and inactivation validation methods.
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Affiliation(s)
- Rasmus Öberg
- Swedish
Defence Research Agency (FOI), Umeå 90621, Sweden
- Department
of Physics, Umeå University, Umeå 90736, Sweden
| | - Timir B. Sil
- Department
of Physics, Umeå University, Umeå 90736, Sweden
| | | | | | - Lars Landström
- Swedish
Defence Research Agency (FOI), Norra Sorunda 13794, Sweden
| | | | - Magnus Andersson
- Department
of Physics, Umeå University, Umeå 90736, Sweden
- Umeå
Centre for Microbial Research (UCMR), Umeå 90736, Sweden
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4
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Oppezzo OJ, Abrevaya XC, Giacobone AFF. An alternative interpretation for tailing in survival curves for bacteria exposed to germicidal radiation. Photochem Photobiol 2024; 100:129-136. [PMID: 37026990 DOI: 10.1111/php.13808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 03/13/2023] [Accepted: 04/02/2023] [Indexed: 04/08/2023]
Abstract
It has been proposed that transient and reversible phenotypic changes could modify the response of bacteria to germicidal radiation, eventually leading to tailing in the survival curves. If this were the case, changes in susceptibility to radiation would reflect variations in gene expression and should only occur in cells in which gene expression is active. To obtain experimental evidence supporting the involvement of phenotypic changes in the origin of tailing, we studied changes in the susceptibility to radiation of cells able to survive high fluences, using split irradiations. Stationary phase cells of Enterobacter cloacae and Deinococcus radiodurans, in which gene expression is active, and spores of Bacillus subtilis, which are dormant cells without active gene expression, were used as microbial models. While cells of E. cloacae and D. radiodurans became susceptible after surviving exposures to high fluences, tolerant spores exhibited unchanged response to radiation. The results can be interpreted assuming that noise in gene expression modifies bacterial susceptibility to radiation, and tailing is the result of intrinsic phenomena of bacterial physiology rather than a technical artifact. For either theoretical or practical purposes, deviations from simple exponential decay kinetics should be considered in estimations of the effects of germicidal radiation at high fluences.
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Affiliation(s)
- Oscar J Oppezzo
- Comisión Nacional de Energía Atómica, Buenos Aires, Argentina
| | - Ximena C Abrevaya
- Instituto de Astronomía y Física del Espacio (UBA-CONICET), Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, UBA, Buenos Aires, Argentina
| | - Ana F F Giacobone
- Comisión Nacional de Energía Atómica, Buenos Aires, Argentina
- Universidad Nacional de Tres de Febrero, Buenos Aires, Argentina
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5
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Coleman CK, Kim J, Bailey ES, Abebe LS, Brown J, Simmons OD, Sobsey MD. Bromine and Chlorine Disinfection of Cryptosporidium parvum Oocysts, Bacillus atrophaeus Spores, and MS2 Coliphage in Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18744-18753. [PMID: 37220325 DOI: 10.1021/acs.est.3c00536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Conventional water treatment practices utilizing chemical disinfection, especially chlorination, are considered generally effective in producing microbiologically safe drinking water. However, protozoan pathogens such as oocysts of Cryptosporidium parvum are very resistant to chlorine, which has led to consideration of alternative disinfectants for their control. Free bromine, HOBr, has not been evaluated extensively as an alternative halogen disinfectant for inactivation of Cryptosporidium parvum in drinking water or reclaimed water for non-potable uses. Bromine is a versatile disinfectant consisting of different chemical forms with persistent microbicidal efficacy under varied water quality conditions and is effective against a range of waterborne microbes of health concern. The objectives of this study are to (1) compare the efficacy of free bromine to free chlorine at similar concentrations (as milligrams per liter) for disinfection of Cryptosporidium parvum oocysts, Bacillus atrophaeus spores, and MS2 coliphage in a model buffered water and (2) evaluate the kinetics of inactivation of these microorganisms using appropriate disinfection models. Overall, at a target concentration of ∼5 mg/L, bromine averaged 0.6 log (73.8%) reductions of C. parvum oocyst infectivity after 300 min (CT: 1166 min·mg/L) and produced up to a 0.8 log reduction disinfectant activity. An ∼5.0 mg/L chlorine dose increased oocyst infectivity by only 0.4 log (64%) after 300 min (CT: 895 min·mg/L). Bacillus atrophaeus spores and MS2 coliphage treated with bromine and chlorine were reduced by 4 log10 (99.99%) for both disinfectants over the duration of the experiments.
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Affiliation(s)
- Collin Knox Coleman
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, 135 Dauer Drive, CB#7431, Chapel Hill, North Carolina 27599, United States
| | - John Kim
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, 135 Dauer Drive, CB#7431, Chapel Hill, North Carolina 27599, United States
| | - Emily S Bailey
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, 135 Dauer Drive, CB#7431, Chapel Hill, North Carolina 27599, United States
| | - Lydia S Abebe
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, 135 Dauer Drive, CB#7431, Chapel Hill, North Carolina 27599, United States
| | - Joe Brown
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, 135 Dauer Drive, CB#7431, Chapel Hill, North Carolina 27599, United States
| | - Otto D Simmons
- College of Agriculture and Life Sciences, North Carolina State University, Campus Box 7601, NC State University Campus, Raleigh, North Carolina 27695, United States
| | - Mark D Sobsey
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, 135 Dauer Drive, CB#7431, Chapel Hill, North Carolina 27599, United States
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6
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Laible AR, Dinius A, Schrader M, Krull R, Kwade A, Briesen H, Schmideder S. Effects and interactions of metal oxides in microparticle-enhanced cultivation of filamentous microorganisms. Eng Life Sci 2022; 22:725-743. [PMID: 36514528 PMCID: PMC9731605 DOI: 10.1002/elsc.202100075] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/13/2021] [Accepted: 09/17/2021] [Indexed: 12/16/2022] Open
Abstract
Filamentous microorganisms are used as molecular factories in industrial biotechnology. In 2007, a new approach to improve productivity in submerged cultivation was introduced: microparticle-enhanced cultivation (MPEC). Since then, numerous studies have investigated the influence of microparticles on the cultivation. Most studies considered MPEC a morphology engineering approach, in which altered morphology results in increased productivity. But sometimes similar morphological changes lead to decreased productivity, suggesting that this hypothesis is not a sufficient explanation for the effects of microparticles. Effects of surface chemistry on particles were paid little attention, as particles were often considered chemically-inert and bioinert. However, metal oxide particles strongly interact with their environment. This review links morphological, physical, and chemical properties of microparticles with effects on culture broth, filamentous morphology, and molecular biology. More precisely, surface chemistry effects of metal oxide particles lead to ion leaching, adsorption of enzymes, and generation of reactive oxygen species. Therefore, microparticles interfere with gene regulation, metabolism, and activity of enzymes. To enhance the understanding of microparticle-based morphology engineering, further interactions between particles and cells are elaborated. The presented description of phenomena occurring in MPEC eases the targeted choice of microparticles, and thus, contributes to improving the productivity of microbial cultivation technology.
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Affiliation(s)
- Andreas Reiner Laible
- School of Life SciencesChair of Process Systems EngineeringTechnische Universität MünchenFreisingGermany
| | - Anna Dinius
- Institute of Biochemical EngineeringTechnische Universität BraunschweigBraunschweigGermany
- Center of Pharmaceutical EngineeringTechnische Universität BraunschweigBraunschweigGermany
| | - Marcel Schrader
- Center of Pharmaceutical EngineeringTechnische Universität BraunschweigBraunschweigGermany
- Institute for Particle TechnologyTechnische Universität BraunschweigBraunschweigGermany
| | - Rainer Krull
- Institute of Biochemical EngineeringTechnische Universität BraunschweigBraunschweigGermany
- Center of Pharmaceutical EngineeringTechnische Universität BraunschweigBraunschweigGermany
| | - Arno Kwade
- Center of Pharmaceutical EngineeringTechnische Universität BraunschweigBraunschweigGermany
- Institute for Particle TechnologyTechnische Universität BraunschweigBraunschweigGermany
| | - Heiko Briesen
- School of Life SciencesChair of Process Systems EngineeringTechnische Universität MünchenFreisingGermany
| | - Stefan Schmideder
- School of Life SciencesChair of Process Systems EngineeringTechnische Universität MünchenFreisingGermany
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7
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Balamurugan S, Zaidi M, Arvaj L, Pendyala B, Gabriel M, Farber JM, Sasges M, Patras A. Modeling the UV-C Inactivation Kinetics and Determination of Fluence Required for Incremental Inactivation of Cronobacter spp. J Food Prot 2022; 85:1625-1634. [PMID: 36075045 DOI: 10.4315/jfp-22-165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 09/02/2022] [Indexed: 11/11/2022]
Abstract
ABSTRACT A study was undertaken to model the UV-C inactivation kinetics and determine the fluences required for the incremental inactivation of several strains of Cronobacter spp. suspended in clear phosphate-buffered saline (PBS). In total, 13 strains of Cronobacter spp. were individually suspended in PBS and treated with UV-C doses of 0, 2, 4, 6, 8, and 10 mJ cm-2 with a collimated beam device emitting UV-C at 253.7 nm. The log reduction from each treatment was identified using the plate count method and plotted against the UV-C dose and then curve fitted using several mathematical models. The UV-C dose required for incremental inactivation of each isolate was determined using both linear and nonlinear regression. For the 13 strains tested, a UV-C dose of 10 mJ cm-2 inactivated between 3.66 ± 0.101 and 5.04 ± 0.465 log CFU mL-1. The survival behavior of all strains was best fitted to the Weibull+tail model, with correlation coefficients between 97.17 and 99.71%, and was used to determine the fluences required for incremental inactivation. The UV-C fluences needed to inactivate 1 log (D10-value) of Cronobacter spp. in buffer were between 3.53 and 5.50 mJ cm-2, whereas a fluence greater than 6.57 mJ cm-2 was required to achieve a 4-log inactivation. A clear understanding of the UV-C dose-response of several strains of Cronobacter spp. lays the foundation to design effective UV-based disinfection systems. HIGHLIGHTS
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Affiliation(s)
- Sampathkumar Balamurugan
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, Ontario, Canada N1G 5C9
| | - Mubashira Zaidi
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, Ontario, Canada N1G 5C9.,Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | - Laura Arvaj
- Guelph Research and Development Centre, Agriculture and Agri-Food Canada, Guelph, Ontario, Canada N1G 5C9
| | - Brahmaiah Pendyala
- Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, Tennessee 37209, USA
| | | | - Jeffrey M Farber
- Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1.,JM Farber Global Food Safety, Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | | | - Ankit Patras
- Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, Tennessee 37209, USA
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8
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Schuit MA, Larason TC, Krause ML, Green BM, Holland BP, Wood SP, Grantham S, Zong Y, Zarobila CJ, Freeburger DL, Miller DM, Bohannon JK, Ratnesar-Shumate SA, Blatchley ER, Li X, Dabisch PA, Miller CC. SARS-CoV-2 inactivation by ultraviolet radiation and visible light is dependent on wavelength and sample matrix. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B: BIOLOGY 2022; 233:112503. [PMID: 35779426 PMCID: PMC9221687 DOI: 10.1016/j.jphotobiol.2022.112503] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/19/2022] [Accepted: 06/18/2022] [Indexed: 11/11/2022]
Abstract
Numerous studies have demonstrated that SARS-CoV-2 can be inactivated by ultraviolet (UV) radiation. However, there are few data available on the relative efficacy of different wavelengths of UV radiation and visible light, which complicates assessments of UV decontamination interventions. The present study evaluated the effects of monochromatic radiation at 16 wavelengths from 222 nm through 488 nm on SARS-CoV-2 in liquid aliquots and dried droplets of water and simulated saliva. The data were used to generate a set of action spectra which quantify the susceptibility of SARS-CoV-2 to genome damage and inactivation across the tested wavelengths. UVC wavelengths (≤280 nm) were most effective for inactivating SARS-CoV-2, although inactivation rates were dependent on sample type. Results from this study suggest that UV radiation can effectively inactivate SARS-CoV-2 in liquids and dried droplets, and provide a foundation for understanding the factors which affect the efficacy of different wavelengths in real-world settings.
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9
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Peng Y, Chen Z, Li Y, Wang Y, Ye C, Xu J, Zhang S. Bacteriostasis and cleaning effect of trace ozone replacing personal care products. ENVIRONMENTAL TECHNOLOGY 2022:1-14. [PMID: 35099355 DOI: 10.1080/09593330.2022.2036818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Ozone is widely used to inactivate bacteria, fungi, and viruses. In recent years, the treatment of itchy skin diseases (eczema and atopic dermatitis) using trace ozone has also received attention. However, the feasibility of using trace ozone to replace personal care products (PCPs) has rarely been analyzed. In this study, the applicability of trace ozone was evaluated in terms of its efficiency for microbial inactivation in three types of skin microbiomes, cleaning performance on simulated human hair and epidermis, safety for simulated human hair, and contribution to emission reduction. The results revealed that at a 10:1 ratio of ozonated water to bacterial suspension, the inactivation ratios of Malassezia, C. albicans, and S. epidermidis reached 99.63%, 83.47%, and 100%, respectively. In addition, the cleaning performance of an ozone solution (0.4 mg/L) for simulated human skin contaminated with carbon black and sebum could reach 95.89% and 95.63%, respectively, with 5 min of washing. The average scores were 0.40 and 0.37 after 5 min and 10 min of ozone treatments, respectively, indicating that trace ozone does not significantly damage simulated human hair. Results also revealed that the total emissions of COD, TP, and TN would be reduced by 1.29×106, 3.55×103, and 3.63×103 mg/ (household · year), respectively, if PCPs are replaced by trace ozone. In short, our findings indicate that trace ozone is a potential alternative to PCPs. By replacing PCPs with trace ozone, the use of synthetic chemical products can be reduced and carbon emissions from oil extraction can be countered.
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Affiliation(s)
- Yanyan Peng
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, PR People's Republic of China
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, PR People's Republic of China
| | - Zhou Chen
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, PR People's Republic of China
| | - Yanzeng Li
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, PR People's Republic of China
| | - Yuantao Wang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, PR People's Republic of China
| | - Chengsong Ye
- Xiamen University, Xiamen, PR People's Republic of China
| | - Junming Xu
- Confosin Technology Co. Ltd., Dongguan, PR People's Republic of China
| | - Shenghua Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, PR People's Republic of China
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10
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Zhang H, Xu X, Tan L, Liang Z, Cao R, Wan Q, Xu H, Wang J, Huang T, Wen G. The aggregation of Aspergillus spores and the impact on their inactivation by chlorine-based disinfectants. WATER RESEARCH 2021; 204:117629. [PMID: 34509870 DOI: 10.1016/j.watres.2021.117629] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/17/2021] [Accepted: 08/29/2021] [Indexed: 06/13/2023]
Abstract
The formation of fungal biofilm goes through some different states, including monodisperse state, aggregated state, germinated state, hyphal and biofilm. The aggregation of spores is a primary step of fungal biofilm development in aquatic systems. Previous studies on the inactivation of fungi were mostly performed in the monodisperse state of fungal spores and biofilm state, however, the inactivation of aggregated fungal spores is still unclear. In this study, the aggregated characteristics of fungal spores (Aspergillus fumigatus and Aspergillus flavus) at different pH values were firstly studied, and the inactivation efficiency of fungal spores at different aggregation degree by chlorine-based disinfectants was also clarified. The results showed that the aggregation degree of Aspergillus fumigatus was the highest at pH 9.0 while it was the lowest at pH 5.0. Aggregation between fungal spores was mainly mediated by occasional adhesin-adhesin interactions and electrostatic interactions. Compared with monodisperse spores, fungal spores were more resistant to chlorine-based disinfectants with the increase of spore aggregation degree. The inactivation rate constants of Aspergillus fumigatus at 30% and 63% aggregation degree were 1.5- and 4-folds lower than that of monodisperse spores, respectively. The lower proportion of membrane damage and higher intracellular reactive oxygen species level for aggregated spores than monodisperse spores was observed according to the flow cytometric results after chlorine-based disinfectants treatment. The reasons for the lower inactivation efficiency of aggregated spores are as following: the protection of outer layer spores and signals between aggregates lead to the increase of resistance for aggregated spores. This study is meaningful for the control of the fungal spores at different states in water.
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Affiliation(s)
- Huan Zhang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Xiangqian Xu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Lili Tan
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Zhiting Liang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Ruihua Cao
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Qiqi Wan
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Huining Xu
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Jingyi Wang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Tinglin Huang
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China
| | - Gang Wen
- Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China.
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11
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Vitzilaiou E, Kuria AM, Siegumfeldt H, Rasmussen MA, Knøchel S. The impact of bacterial cell aggregation on UV inactivation kinetics. WATER RESEARCH 2021; 204:117593. [PMID: 34482094 DOI: 10.1016/j.watres.2021.117593] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 07/14/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
Reconditioning of food processing water streams for reuse is an increasingly common water management practice in the food industry and UV disinfection is often employed as part of the water treatment. Several factors may impact the effect of UV radiation. Here, we aim to assess the impact of cell aggregation on UV inactivation kinetics and investigate if UV exposure induces aggregation. Three strains, isolated from food processing water reuse lines (Raoultella ornithinolytica, Pseudomonas brenneri, Rothia mucilaginosa) and both an aggregating and a non-aggregating strain of Staphylococcus aureus were exposed to UVC light at 255 nm using UV LED equipment. Total Viable Count and phase-contrast microscopy, coupled with image analysis, were used to compare the UV inactivation kinetics with the average particle size for a range of UV doses. Tailing effect, seen as a strong reduction in inactivation rate, was observed for all strains at higher UV doses (industrial strains ≥ 50 or 120 mJ/cm2, S. aureus strains ≥ 40 or 60 mJ/cm2). The naturally aggregating strains were more UV tolerant, both within and between species. When aggregates of S. aureus were broken, UV tolerance decreased. For the processing water isolates, the lowest applied UV dose (25 mJ/cm2) significantly increased the average particle size. Application of higher UV doses obtained with longer exposure times did not further increase the particle size compared with untreated samples. For the S. aureus strains, however, no consistent change in average particle size was observed due to UV. Our results demonstrate that aggregating strains have a higher degree of protection and that UV radiation induces aggregation in some, but not all bacteria. A better understanding of the mechanisms governing microbial aggregation and survival during UV treatment could help to improve UV applications and predictions of microbial inactivation.
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Affiliation(s)
- Eirini Vitzilaiou
- Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, DK-1958, Frederiksberg C, Denmark.
| | - Asaph M Kuria
- Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, DK-1958, Frederiksberg C, Denmark
| | - Henrik Siegumfeldt
- Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, DK-1958, Frederiksberg C, Denmark
| | - Morten A Rasmussen
- Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, DK-1958, Frederiksberg C, Denmark; COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Susanne Knøchel
- Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, DK-1958, Frederiksberg C, Denmark
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12
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Assessing the photodynamic efficacy of different photosensitizer-light treatments against foodborne bacteria based on the number of absorbed photons. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2021; 221:112249. [PMID: 34237541 DOI: 10.1016/j.jphotobiol.2021.112249] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/15/2021] [Accepted: 06/25/2021] [Indexed: 11/27/2022]
Abstract
Increasing interests in photodynamic treatment (PDT) for food preservation require a holistic method to evaluate and compare different photosensitizer (PS)-light treatments. In this report, the absorbed photons were used as the basis to assess the antimicrobial photodynamic efficacy of two PSs, chlorophyllin sodium magnesium salt (Chl-Mg) and chlorophyllin sodium copper salt (Chl-Cu), under blue and white light against two typical foodborne pathogens, Gram-negative Escherichia coli, and Gram-positive Staphylococcus aureus. The results showed that the phototoxicity of a PS was predominantly decided by the absorbed photons rather than the characteristics of light sources. Photosensitized Chl-Mg exhibited superior antimicrobial activity as compared to that of ChlCu. The applied treatments were found to be more effective against S. aureus than E. coli. Bacterial inactivation kinetics as a function of the number of absorbed photons could be described by Weibull model with R2 from 0.947-0.962, and kinetics constants D in the range of 0.202 × 1017 photons/cm2-2.409 × 1018 photons/cm2. The kinetics models may find promising applications in the design, assessment, and optimization of PDT processes.
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13
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Phattarapattamawong S, Chareewan N, Polprasert C. Comparative removal of two antibiotic resistant bacteria and genes by the simultaneous use of chlorine and UV irradiation (UV/chlorine): Influence of free radicals on gene degradation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 755:142696. [PMID: 33059146 DOI: 10.1016/j.scitotenv.2020.142696] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/12/2020] [Accepted: 09/27/2020] [Indexed: 06/11/2023]
Abstract
The research aimed to remove antibiotic resistance by the simultaneous use of UV irradiation and chlorine (UV/chlorine). The inactivations of tetracycline resistant bacteria (TRB) during chlorination, UV irradiation, and UV/chlorine was investigated and compared with those of amoxicillin resistant bacteria (AmRB). Similar examination was also conducted for comparing the removals of their resistant genes (i.e., tetM and blaTem). The removals of antibiotic resistance highly depended on chlorine doses and UV intensities. The sufficient chlorine dose (20 mg.L-1) in the chlorination and the UV/chlorine completely inactivated TRB and AmRB (>7.3 log), while the UV irradiation could not achieve the complete disinfection. Microorganisms resistant to different antibiotics exhibit different susceptibility to the disinfection processes. The removals of antibiotic resistant genes (i.e., tetM and blaTem) were more difficult than those of TRB and AmRB. The UV/chlorine was the greatest process for tetM and blaTem removals, followed by chlorination and UV irradiation, respectively. Chlorination decreased the tetM and blaTem by 0.40-1.45 log and 1.04-2.45 log, respectively. The blaTem gene was highly reactive to chlorine, compared with tetM. The UV irradiation caused the tetM and blaTem reductions by 0.32-0.91 log and 0.59-0.96 log, respectively. The UV/chlorine improved the tetM and blaTem removals by 0.98-3.20 log and 1.28-3.36 log, respectively. The •OH contributed to the fraction of tetM and blaTem removals by 48% and 19%, respectively. The effect of reactive chlorine species on the tetM and blaTem removals was minor. The pseudo 1st-order kinetic constants (k') for tetM and blaTem removals by the UV/chlorine were highest. The •OH enhanced the k' values by 120% and 20% for the tetM and blaTem removals, respectively. The study showed the potential use of UV/chlorine for controlling antibiotic resistance.
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Affiliation(s)
- Songkeart Phattarapattamawong
- Department of Environmental Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Thailand; Center of Excellence on Hazardous Substance Management (HSM), Thailand.
| | - Narissara Chareewan
- Department of Environmental Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi (KMUTT), Thailand
| | - Chongrak Polprasert
- Department of Civil Engineering, Faculty of Engineering, Thammasat University, Thailand
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14
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Kim DK, Kang DH. Investigation of a new UVC LEDs array continuous type water disinfection system for inactivating Escherichia coli O157:H7 according to flow rate and electrical energy efficiency analysis. Food Control 2021. [DOI: 10.1016/j.foodcont.2020.107470] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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Schuit M, Gardner S, Wood S, Bower K, Williams G, Freeburger D, Dabisch P. The Influence of Simulated Sunlight on the Inactivation of Influenza Virus in Aerosols. J Infect Dis 2020; 221:372-378. [PMID: 31778532 DOI: 10.1093/infdis/jiz582] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 11/18/2019] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Environmental parameters, including sunlight levels, are known to affect the survival of many microorganisms in aerosols. However, the impact of sunlight on the survival of influenza virus in aerosols has not been previously quantified. METHODS The present study examined the influence of simulated sunlight on the survival of influenza virus in aerosols at both 20% and 70% relative humidity using an environmentally controlled rotating drum aerosol chamber. RESULTS Measured decay rates were dependent on the level of simulated sunlight, but they were not significantly different between the 2 relative humidity levels tested. In darkness, the average decay constant was 0.02 ± 0.06 min-1, equivalent to a half-life of 31.6 minutes. However, at full intensity simulated sunlight, the mean decay constant was 0.29 ± 0.09 min-1, equivalent to a half-life of approximately 2.4 minutes. CONCLUSIONS These results are consistent with epidemiological findings that sunlight levels are inversely correlated with influenza transmission, and they can be used to better understand the potential for the virus to spread under varied environmental conditions.
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Affiliation(s)
- Michael Schuit
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the US Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Sierra Gardner
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the US Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Stewart Wood
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the US Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Kristin Bower
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the US Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Greg Williams
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the US Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Denise Freeburger
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the US Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
| | - Paul Dabisch
- National Biodefense Analysis and Countermeasures Center, Operated by BNBI for the US Department of Homeland Security Science and Technology Directorate, Frederick, MD, USA
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16
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Penetration and Microbial Inactivation by High Voltage Atmospheric Cold Plasma in Semi-Solid Material. FOOD BIOPROCESS TECH 2020. [DOI: 10.1007/s11947-020-02506-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Zewde AA, Li Z, Zhang L, Odey EA, Xiaoqin Z. Utilisation of appropriately treated wastewater for some further beneficial purposes: a review of the disinfection method of treated wastewater using UV radiation technology. REVIEWS ON ENVIRONMENTAL HEALTH 2020; 35:139-146. [PMID: 31743106 DOI: 10.1515/reveh-2019-0066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 10/17/2019] [Indexed: 06/10/2023]
Abstract
Due to world population growth, global climate change and the deteriorated quality of water, water supply struggles to keep up the clean water demand to meet human needs. Ultraviolet (UV) technology holds a great potential in advancing water and wastewater treatment to improve the efficiency of safe treatment. Over the last 20 years, the UV light disinfection industry has shown a tremendous growth. Therefore, reuse of wastewater contributes significantly to an efficient and sustainable water usage. Disinfection is a requirement for wastewater reuse due to the presence of a swarm of pathogens (e.g. bacteria, viruses, worms and protozoa) in secondary effluents. UV technology is widely favoured due to its environmentally friendly, chemical-free ability to provide high-log reductions of all known microorganisms, including chlorine-resistant strains such as Cryptosporidium. The UV disinfection process does not create disinfection by-products and unlike the chlorine UV disinfection process, it is not reliant on water temperature and pH. UV disinfection can eliminate the need to generate, handle, transport or store toxic/hazardous or corrosive chemicals and requires less space than other methods. As UV does not leave any residual effect that can be harmful to humans or aquatic life, it is safer for plant operators.
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Affiliation(s)
- Abraham Amenay Zewde
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Xueyuan 30, Beijing 10003, P.R. China
| | - Zifu Li
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, P.R. China
| | - Lingling Zhang
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, P.R. China
| | - Emanuel Alepu Odey
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, P.R. China
| | - Zhou Xiaoqin
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, P.R. China
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18
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Kowalski W, Bahnfleth W, Raguse M, Moeller R. The cluster model of ultraviolet disinfection explains tailing kinetics. J Appl Microbiol 2019; 128:1003-1014. [DOI: 10.1111/jam.14527] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/06/2019] [Accepted: 11/20/2019] [Indexed: 01/27/2023]
Affiliation(s)
| | - W.P. Bahnfleth
- The Pennsylvania State University University Park PA USA
| | - M. Raguse
- Space Microbiology Research Group Radiation Biology Department German Aerospace Center (DLR e.V.) Institute of Aerospace Medicine Cologne Germany
| | - R. Moeller
- Space Microbiology Research Group Radiation Biology Department German Aerospace Center (DLR e.V.) Institute of Aerospace Medicine Cologne Germany
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19
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Wedel C, Wenning M, Dettling A, Scherer S, Hinrichs J. Resistance of thermophilic spore formers isolated from milk and whey products towards cleaning-in-place conditions: Influence of pH, temperature and milk residues. Food Microbiol 2019; 83:150-158. [DOI: 10.1016/j.fm.2019.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 04/29/2019] [Accepted: 05/04/2019] [Indexed: 01/04/2023]
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20
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A tryptophan synchronous and normal fluorescence study on bacteria inactivation mechanism. Proc Natl Acad Sci U S A 2019; 116:18822-18826. [PMID: 31481620 DOI: 10.1073/pnas.1909722116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The UV photodissociation kinetics of tryptophan amino acid, Trp, attached to the membrane of bacteria, Escherichia coli and Bacillus subtilis, have been studied by means of normal and synchronous fluorescence. Our experimental data suggest that the fluorescence intensity of Trp increases during the first minute of irradiation with 250 nm to ∼ 280 nm, 7 mW/cm2 UV light, and subsequently decreases with continuous irradiation. During this short, less than a minute, period of time, 70% of the 107 cell per milliliter bacteria are inactivated. This increase in fluorescence intensity is not observed when tryptophan is in the free state, namely, not attached to a protein, but dissolved in water or saline solution. This increase in fluorescence is attributed to the additional fluorescence of tryptophan molecules formed by protein unfolding, the breakage of the bond that attaches Trp to the bacterial protein membrane, or possibly caused by the irradiation of 2 types of tryptophan residues that photolyze with different quantum yields.
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21
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Guo L, Ye C, Cui L, Wan K, Chen S, Zhang S, Yu X. Population and single cell metabolic activity of UV-induced VBNC bacteria determined by CTC-FCM and D 2O-labeled Raman spectroscopy. ENVIRONMENT INTERNATIONAL 2019; 130:104883. [PMID: 31229870 DOI: 10.1016/j.envint.2019.05.077] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 05/19/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
The occurrence of viable but non-culturable (VBNC) bacteria will result in significant underestimation of viable bacterial counts in drinking water. Whereas, much is unknown in characterizing their viability. In this study, two environmental isolates (Aeromonas sp. and Pseudomonas sp.) and two model strains (E. coli and S. aureus) were induced into VBNC state by UV irradiation. Then, their metabolic activity was determined by 5-cyano-2,3-ditolyl tetrazolium chloride combination flow cytometry (CTC-FCM) and D2O-labeled Raman spectroscopy, respectively, at both population and single cell levels. The results showed that almost all strains could enter VBNC state irradiated by ≥ 5 mJ/cm2 UV. When determined by CTC-FCM, the population metabolic activity for each strain did not vary significantly (p > 0.05) unless the UV dose reached 200 mJ/cm2. Their single cell activity spectrum narrowed slightly, as indicated by changes in the standard deviation of the logarithmic normal distribution (σ) of 0.015-0.033. This minute difference suggested the CTC-FCM method was suitable for assessing the essential viability of VBNC bacteria. With respect to Raman method, an obvious dose-response effect was recorded. With the UV dosages increased from 10 to 200 mJ/cm2, the CD/(CD + CH) for the four strains were reduced to between 95.7% and 47.9% of unirradiated controls, depending on strain and UV dose. Meanwhile, the single cellular Raman spectrum showed much more heterogeneously metabolic activity distribution, with some cells even entering metabolic "silence". Considering the ubiquitous participation of water in biochemical processes, the Raman method was more appropriate in assessing the overall metabolic activity. The above findings can not only be a reference for VBNC mechanism studies, but also have the potential in optimizing disinfection and other bacterial removal processes.
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Affiliation(s)
- Lizheng Guo
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Chengsong Ye
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Li Cui
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Kun Wan
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Sheng Chen
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Shenghua Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Xin Yu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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22
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Léziart T, Dutheil de la Rochere PM, Cheswick R, Jarvis P, Nocker A. Effect of turbidity on water disinfection by chlorination with the emphasis on humic acids and chalk. ENVIRONMENTAL TECHNOLOGY 2019; 40:1734-1743. [PMID: 30777799 DOI: 10.1080/09593330.2019.1585480] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/14/2019] [Indexed: 06/09/2023]
Abstract
Chlorine is globally the most widely used chemical for water disinfection. Whereas disinfection efficiency is well known to depend on water pH and temperature, the effect of turbidity is less well studied. Although turbidity is measured online in most drinking water works and most countries where regulations exist have set limits of <1 NTU for water leaving the works, the composition of turbidity is typically unknown. Given the heterogeneous nature of substances contributing to turbidity, the aim of this work was to study the effect of selected compounds on chlorination efficacy. The effect of humic acids and chalk on the inactivation of the indicator bacteria Escherichia coli and Enterococcus faecalis was assessed at neutral pH at different turbidity levels using both plate counting and flow cytometry in combination with membrane integrity staining. For humic acids, a turbidity of 1 NTU (corresponding to 2 mg L-1) was identified as a critical threshold, which when exceeded was found to have a negative impact on chlorine disinfection. Chalk, on the other hand, had no measurable impact up to 5 NTU. The observation applied to both bacterial species with identical conclusions from the two diagnostic methods. Results corroborate that different turbidity causing substances affect chlorination efficiency to very different extents with chlorine demand by organic material probably being the most important determinant. In the case of turbidities >1 NTU, turbidity measurement benefits from the consideration of the organic content as mere NTU values do not allow predicting an impact on chlorination efficiency.
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Affiliation(s)
- Tangui Léziart
- a Cranfield Water Science Institute , Cranfield University , Cranfield , UK
| | | | - Ryan Cheswick
- a Cranfield Water Science Institute , Cranfield University , Cranfield , UK
| | - Peter Jarvis
- a Cranfield Water Science Institute , Cranfield University , Cranfield , UK
| | - Andreas Nocker
- a Cranfield Water Science Institute , Cranfield University , Cranfield , UK
- b IWW Water Centre , Mülheim an der Ruhr , Germany
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23
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Umar M, Roddick F, Fan L. Moving from the traditional paradigm of pathogen inactivation to controlling antibiotic resistance in water - Role of ultraviolet irradiation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 662:923-939. [PMID: 30795480 DOI: 10.1016/j.scitotenv.2019.01.289] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
Ultraviolet (UV) irradiation has proven an effective tool for inactivating microorganisms in water. There is, however, a need to look at disinfection from a different perspective because microbial inactivation alone may not be sufficient to ensure the microbiological safety of the treated water since pathogenic genes may still be present, even after disinfection. Antibiotic resistance genes (ARGs) are of a particular concern since they enable microorganisms to become resistant to antibiotics. UV irradiation has been widely used for disinfection and more recently for destroying ARGs. While UV lamps remain the principal technology to achieve this objective, UV light emitting diodes (UV-LEDs) are novel sources of UV irradiation and have increasingly been reported in lab-scale investigations as a potential alternative. This review discusses the current state of the applications of UV technology for controlling antibiotic resistance during water and wastewater treatment. Since UV-LEDs possess several attractive advantages over conventional UV lamps, the impact of UV-LED characteristics (single vs combined wavelengths, and operational parameters such as periodic or pulsed and continuous irradiation, pulse repetition frequencies, duty cycle), type of organism, and fluence response, are critically reviewed with a view to highlighting the research needs for addressing future disinfection challenges. The energy efficiency of the reported UV processes is also evaluated with a focus on relating the findings to disinfection efficacy. The greater experience with UV lamps could be useful for investigating UV-LEDs for similar applications (i.e., antibiotic resistance control), and hence identification of future research directions.
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Affiliation(s)
- Muhammad Umar
- Norwegian Institute for Water Research (NIVA), Gaustadallèen 21, NO-0349 Oslo, Norway.
| | - Felicity Roddick
- Department of Chemical and Environmental Engineering, School of Engineering, RMIT University, Melbourne 3001, Australia
| | - Linhua Fan
- Department of Chemical and Environmental Engineering, School of Engineering, RMIT University, Melbourne 3001, Australia
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24
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Li X, Cai M, Wang L, Niu F, Yang D, Zhang G. Evaluation survey of microbial disinfection methods in UV-LED water treatment systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 659:1415-1427. [PMID: 31096352 DOI: 10.1016/j.scitotenv.2018.12.344] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/22/2018] [Accepted: 12/22/2018] [Indexed: 05/06/2023]
Abstract
Ultraviolet (UV) disinfection is an early discovered technology that is currently and widely used for water treatment and food hygiene treatment. A newly emerging technology of UV disinfection, that is, UV light-emitting diodes (UV-LEDs), has aroused considerable research attention. UV-LEDs feature numerous advantages compared with traditional UV mercury vapor lamps and are expected to replace traditional UV lamps. Researchers currently perform studies to obtain data and develop methods for UV-LED water treatment systems. This article analyzes the latest research status and discusses the types of inactivation factors, such as the wavelength selectivity of UV light source, control of UV dose, effect of inactivation rate constant (K) (cm2/mJ), working mode of water sample, external auxiliary system, and UV sensitivity of pathogenic bacteria in water. The wavelengths of approximately 260 and 280 nm normally feature strong inactivation characteristics. When compared with the approximately 260 nm wavelength chip, the around 280 nm wavelength chip proves to be a better choice as its higher wavelength light power can result in faster disinfection capacity of bacteria. UV dose can also be used as the reference value for disinfection of drinking water, whereas the inactivation rate constant (K) (cm2/mJ) varies with different microorganism internal structures. Changing the working mode or adding an auxiliary system can also enhance the inactivation effect in water treatment system settings. In addition, we can compare the inactivation capacities of several pathogens as follows: ΦX174 > Escherichia coli > T type bacteriophage >Bacillus subtilis > MS2 or Qβ > human adenovirus. The in-depth investigation and discussion of inactivation factors and the mechanism of action in UV-LEDs water treatment systems will establish a more efficient UV-LED disinfection method in the future, provide a guiding direction, and promote the standardization and normalization of pathogen inactivation mechanism in UV-LED water treatment systems.
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Affiliation(s)
- Xiaoling Li
- School of Mechanism and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China
| | - Miao Cai
- School of Mechanism and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China.
| | - Lei Wang
- School of Mechanism and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China
| | - Fanfan Niu
- School of Mechanism and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China
| | - Daoguo Yang
- School of Mechanism and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China.
| | - Guoqi Zhang
- School of Mechanism and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China; Delft Institute of Microsystems and Nanoelectronics (Dimes), Delft University of Technology, Mekelweg 6, 2628CD Delft, the Netherlands
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Russo N, Marzo A, Randazzo C, Caggia C, Toscano A, Cirelli GL. Constructed wetlands combined with disinfection systems for removal of urban wastewater contaminants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 656:558-566. [PMID: 30529960 DOI: 10.1016/j.scitotenv.2018.11.417] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 11/27/2018] [Accepted: 11/27/2018] [Indexed: 06/09/2023]
Abstract
The removal efficiency of an urban wastewater treatment plant (WWTP) to obtain an effluent suitable for agriculture reuse was evaluated in a one-year period, taking into account the Italian wastewater limits and the recent European proposal for the minimum requirements water quality for agricultural irrigation. The secondary effluent of WWTP was treated by three full-scale horizontal sub-surface flow (H-SSF) constructed wetlands (CWs), working in parallel, planted with different macrophytes species, and combined with a UV device and a lagooning system running in series. The H-SSF CW system effectively reduced physico-chemical pollutants and its efficiency was steady over the investigation period, while, Escherichia coli densities always exceed the Italian limits required for wastewater reuse in agriculture. The UV system significantly reduced the microbiological indicators, eliminating E. coli, in compliance with the Italian regulation, and somatic coliphages, although a variable efficacy against total coliforms and enterococci, especially in winter season, was achieved. Although the lagooning unit provides a high removal of the main microbial groups, it did not reduce physico-chemical parameters. Even if the overall performance target, for the whole treatment chain, met the recent log10 reduction (≥5.0), required by the European Commission, the persistence of enterococci, especially in winter season, poses a matter of concern for public health, for the potential risk to serve as a genetic reservoir of transferable antibiotic-resistance.
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Affiliation(s)
- Nunziatina Russo
- Department of Agricultural, Food and Environment (Di3A), University of Catania, Via Santa Sofia 100, Catania 95123, Italy
| | - Alessia Marzo
- Center for the Conservation and Management of Nature and Agroecosystems (CUTGANA), University of Catania, via Santa Sofia 98, 95123 Catania, Italy.
| | - Cinzia Randazzo
- Department of Agricultural, Food and Environment (Di3A), University of Catania, Via Santa Sofia 100, Catania 95123, Italy
| | - Cinzia Caggia
- Department of Agricultural, Food and Environment (Di3A), University of Catania, Via Santa Sofia 100, Catania 95123, Italy
| | - Attilio Toscano
- Department of Agricultural and Food Sciences (DISTAL), Alma Mater Studiorum-University of Bologna, Viale Giuseppe Fanin 50, 40127 Bologna, Italy
| | - Giuseppe Luigi Cirelli
- Department of Agricultural, Food and Environment (Di3A), University of Catania, Via Santa Sofia 100, Catania 95123, Italy
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Hojnik N, Modic M, Ni Y, Filipič G, Cvelbar U, Walsh JL. Effective Fungal Spore Inactivation with an Environmentally Friendly Approach Based on Atmospheric Pressure Air Plasma. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:1893-1904. [PMID: 30657659 PMCID: PMC6727216 DOI: 10.1021/acs.est.8b05386] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Fungal contamination of surfaces is a global burden, posing a major environmental and public health challenge. A wide variety of antifungal chemical agents are available; however, the side effects of the use of these disinfectants often result in the generation of toxic residues raising major environmental concerns. Herein, atmospheric pressure air plasma generated by a surface barrier discharge (SBD) is presented as an innovative green chemical method for fungal inactivation, with the potential to become an effective replacement for conventional chemical disinfection agents, such as Virkon. Using Aspergillus flavus spores as a target organism, a comparison of plasma based decontamination techniques is reported, highlighting their respective efficiencies and uncovering their underpining inactivation pathways. Tests were performed using both direct gaseous plasma treatment and an indirect treatment using a plasma activated aqueous broth solution (PAB). Concentrations of gaseous ozone and nitrogen oxides were determined with Fourier-transform infrared spectroscopy (FTIR) and Optical emission spectroscopy (OES), whereas hydrogen peroxides, nitrites, nitrates, and pH were measured in PAB. It is demonstrated that direct exposure to the gaseous plasma effluent exhibited superior decontamination efficiency and eliminated spores more effectively than Virkon, a finding attributed to the production of a wide variety of reactive oxygen and nitrogen species within the plasma.
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Affiliation(s)
- Nataša Hojnik
- Jozef Stefan Institute , Ljubljana , Slovenia
- Jozef Stefan International Postgraduate School , Ljubljana , Slovenia
| | | | - Yuan Ni
- Department of Electrical Engineering and Electronics , University of Liverpool , Liverpool , United Kingdom
| | | | - Uroš Cvelbar
- Jozef Stefan Institute , Ljubljana , Slovenia
- Jozef Stefan International Postgraduate School , Ljubljana , Slovenia
| | - James L Walsh
- Department of Electrical Engineering and Electronics , University of Liverpool , Liverpool , United Kingdom
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Shoults DC, Ashbolt NJ. Decreased efficacy of UV inactivation of Staphylococcus aureus after multiple exposure and growth cycles. Int J Hyg Environ Health 2019; 222:111-116. [DOI: 10.1016/j.ijheh.2018.08.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 08/14/2018] [Accepted: 08/14/2018] [Indexed: 10/28/2022]
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Douterelo I, Fish KE, Boxall JB. Succession of bacterial and fungal communities within biofilms of a chlorinated drinking water distribution system. WATER RESEARCH 2018; 141:74-85. [PMID: 29778067 DOI: 10.1016/j.watres.2018.04.058] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 04/05/2018] [Accepted: 04/25/2018] [Indexed: 06/08/2023]
Abstract
Understanding the temporal dynamics of multi-species biofilms in Drinking Water Distribution Systems (DWDS) is essential to ensure safe, high quality water reaches consumers after it passes through these high surface area reactors. This research studied the succession characteristics of fungal and bacterial communities under controlled environmental conditions fully representative of operational DWDS. Microbial communities were observed to increase in complexity after one month of biofilm development but they did not reach stability after three months. Changes in cell numbers were faster at the start of biofilm formation and tended to decrease over time, despite the continuing changes in bacterial community composition. Fungal diversity was markedly less than bacterial diversity and had a lag in responding to temporal dynamics. A core-mixed community of bacteria including Pseudomonas, Massillia and Sphingomonas and the fungi Acremonium and Neocosmopora were present constantly and consistently in the biofilms over time and conditions studied. Monitoring and managing biofilms and such ubiquitous core microbial communities are key control strategies to ensuring the delivery of safe drinking water via the current ageing DWDS infrastructure.
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Affiliation(s)
- I Douterelo
- Pennine Water Group, Department of Civil and Structural Engineering, Mappin Street, University of Sheffield, Sheffield, S1 3JD, UK.
| | - K E Fish
- Pennine Water Group, Department of Civil and Structural Engineering, Mappin Street, University of Sheffield, Sheffield, S1 3JD, UK
| | - J B Boxall
- Pennine Water Group, Department of Civil and Structural Engineering, Mappin Street, University of Sheffield, Sheffield, S1 3JD, UK
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Kviatkovski I, Mamane H, Lakretz A, Sherman I, Beno-Moualem D, Minz D. Resistance of a multiple-isolate marine culture to ultraviolet C irradiation: inactivation vs biofilm formation. Lett Appl Microbiol 2018; 67:278-284. [PMID: 29901218 DOI: 10.1111/lam.13032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 04/26/2018] [Accepted: 06/11/2018] [Indexed: 11/30/2022]
Abstract
Ultraviolet (UV) irradiation is an emerging strategy for controlling the formation of undesired biofilms in water desalination facilities using reverse osmosis (RO). However, most studies examining these pretreatments are limited as they have been conducted on single-species cultures, while biofilms are composed of multiple-species communities. The goal of this study was to investigate the effect of UV-C irradiation on a model community composed of six environmental isolates from a marine biofilm formed in RO seawater desalination plant. There was a high variance in the susceptibility of the single-isolate cultures to UV-C, from no response (isolate Eryth23) to complete inactivation (isolate Vib3). The most active wavelength was around 260 nm, resulting in a loss of viability of single-isolate cultures and loss of vitality of the mixed-isolate cultures. With respect to biofilm formation, the activity of this wavelength was completely different compared to its activity on planktonic suspension. Irradiation with 260 nm did not inhibit the total biofilm formation by the six-isolate culture; moreover, isolates such as the resistant Eryth23 or the susceptible Pseudoalt17, even gained abundance in the mixed isolate biofilm. The only decrease in total biofilm was obtained from irradiation at 280 nm, which was less active against the planktonic culture. These results indicate that the complexity of the biofilm-forming microbial community may contribute to its resistance to UV-C irradiation. SIGNIFICANCE AND IMPACT OF THE STUDY This study examined the resistance of a multiple-isolate native marine culture to UV-C irradiation, in terms of viability, vitality and the ability to form biofilm. Results of this study showed that even though most of the cells were inactivated both in single-isolate and in multiple-isolate cultures, still the multiple-isolate cultures manages to form biofilms, surprisingly with higher biomass than without irradiation. The significance of the study is in its conclusion that studies on UV-C irradiation of biofilm-forming model micro-organisms are not always applicable to natural multiple-species communities.
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Affiliation(s)
- I Kviatkovski
- Department of Soil, Water, and Environmental Sciences, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel.,Robert H. Smith Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
| | - H Mamane
- Faculty of Engineering, School of Mechanical Engineering and Water Research Center (TAU-WRC), Tel Aviv University, Tel Aviv, Israel
| | - A Lakretz
- Faculty of Engineering, School of Mechanical Engineering and Water Research Center (TAU-WRC), Tel Aviv University, Tel Aviv, Israel
| | - I Sherman
- Faculty of Engineering, School of Mechanical Engineering and Water Research Center (TAU-WRC), Tel Aviv University, Tel Aviv, Israel
| | - D Beno-Moualem
- Department of Postharvest Science, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
| | - D Minz
- Department of Soil, Water, and Environmental Sciences, Agricultural Research Organization, Volcani Center, Bet Dagan, Israel
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Lee H, Jin Y, Hong S. Understanding possible underlying mechanism in declining germicidal efficiency of UV-LED reactor. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2018; 185:136-142. [PMID: 29902744 DOI: 10.1016/j.jphotobiol.2018.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 06/04/2018] [Accepted: 06/05/2018] [Indexed: 11/26/2022]
Abstract
Since ultraviolet light emitting diodes (UV-LEDs) have emerged as an alternative light source for UV disinfection systems, enhancement of reactor performance is a demanding challenge to promote its practical application in water treatment process. This study explored the underlying mechanism of the inefficiency observed in flow-through mode UV disinfection tests to improve the light utilization of UV-LED applications. In particular, the disinfection performance of UV-LED reactors was evaluated using two different flow channel types, reservoir and pathway systems, in order to elucidate the impact of physical circumstances on germicidal efficiency as the light profile was adjusted. Overall, a significant reduction in germicidal efficiency was observed when exposure time was prolonged or a mixing chamber was integrated. Zeta analysis revealed that the repulsion rate between microorganisms decreased with UV fluence transfer, and that change might cause the shielding effect of UV delivery to target microorganisms. In line with the above findings, the reduction in efficiency intensified when opportunities for microbial collision increased. Thus, UV induced microbial aggregation was implicated as being a disinfection hindering factor, exerting its effect through uneven UV illumination. Ultimately, the results refuted the prevailing belief that UV has a cumulative effect. We found that the reservoir system achieved worse performance than the pathway system despite it providing 15 times higher UV fluence: the differences in germicidal efficiency were 1-log, 1.4-log and 1.7-log in the cases of P.aeruginosa, E.coli and S.aureus, respectively.
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Affiliation(s)
- Hyunkyung Lee
- School of Civil, Environmental and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Yongxun Jin
- School of Civil, Environmental and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea; Center for Water Resource Cycle Research, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Seungkwan Hong
- School of Civil, Environmental and Architectural Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
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Silva RG, Szabo J, Namboodiri V, Krishnan ER, Rodriguez J, Zeigler A. Evaluation of an environmentally sustainable UV-assisted water treatment system for the removal of Bacillus globigii spores in water. WATER SCIENCE & TECHNOLOGY, WATER SUPPLY 2018; 18:968-975. [PMID: 30505259 PMCID: PMC6260950 DOI: 10.2166/ws.2017.165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Development of greener water treatment technologies is important for the production of safe drinking water and water security applications, such as decontamination. Chlorine assisted disinfection is common and economical, but can generate disinfection byproducts (DBPs) that may be of health concern. DBPs are formed due to the reaction of chlorine with naturally occurring organic and inorganic substances in water. Currently, various innovative technologies are being developed as alternative approaches for preventing DBPs during water treatment. In this study, we evaluated the effectiveness of a novel combination of high efficiency flow filtration and UV disinfection treatment system for the removal of Bacillus globigii (B. globigii) spores in water. The filtration system consists of a charged membrane filter (CMF) that not only helps to remove suspended particles but also reduces the impact of other impurities including bio organisms. In order to get most performance details, the CMF was evaluated at clean, half-life, and end of life (EOL) conditions along with 100% UV transmittance (UVT). In addition, the effectiveness of the UV system was evaluated as a stand alone system at 100% and 70% EOL intensity. The study was conducted at the US EPA's Test and Evaluation (T&E) Facility in Cincinnati, OH, using B. globigii, a surrogate for B. anthracis spores. This non-chemical environmentally-friendly CMF/UV combination system and the stand alone UV unit showed greater than 6.0 log removal of B. globigii during the tests.
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Affiliation(s)
- R G Silva
- APTIM, Test and Evaluation Facility, 1600 Gest Street, Cincinnati, OH 45204, USA
| | - J Szabo
- US EPA, National Homeland Security Research Center, Cincinnati, OH, USA
| | - V Namboodiri
- US EPA, National Risk Management Research Laboratory, Cincinnati, OH, USA
| | - E R Krishnan
- APTIM, Test and Evaluation Facility, 1600 Gest Street, Cincinnati, OH 45204, USA
| | - J Rodriguez
- Aqua Treatment Service, Mechanicsburg, PA, USA
| | - A Zeigler
- Waterline Technology, Mansfield, OH, USA
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UV-LED radiation modeling and its applications in UV dose determination for water treatment. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2017.10.047] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Zhang C, Xu L, Wang X, Zhuang K, Liu Q. Effects of ultraviolet disinfection on antibiotic-resistantEscherichia colifrom wastewater: inactivation, antibiotic resistance profiles and antibiotic resistance genes. J Appl Microbiol 2017; 123:295-306. [DOI: 10.1111/jam.13480] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/20/2017] [Accepted: 04/25/2017] [Indexed: 12/01/2022]
Affiliation(s)
- C.M. Zhang
- School of Environmental and Municipal Engineering; Xi'an University of Architecture and Technology; Xi'an China
- International Science and Technology Cooperation Center for Urban Alternative Water Resources Development; Xi'an China
- Key Lab of Northwest Water Resource, Environment and Ecology; MOE; Xi'an University of Architecture and Technology; Xi'an China
- Engineering Technology Research Center for Wastewater Treatment and Reuse; Shaanxi Province Xi'an China
| | - L.M. Xu
- School of Environmental and Municipal Engineering; Xi'an University of Architecture and Technology; Xi'an China
- Key Lab of Northwest Water Resource, Environment and Ecology; MOE; Xi'an University of Architecture and Technology; Xi'an China
- Engineering Technology Research Center for Wastewater Treatment and Reuse; Shaanxi Province Xi'an China
| | - X.C. Wang
- School of Environmental and Municipal Engineering; Xi'an University of Architecture and Technology; Xi'an China
- International Science and Technology Cooperation Center for Urban Alternative Water Resources Development; Xi'an China
- Key Lab of Northwest Water Resource, Environment and Ecology; MOE; Xi'an University of Architecture and Technology; Xi'an China
- Engineering Technology Research Center for Wastewater Treatment and Reuse; Shaanxi Province Xi'an China
| | - K. Zhuang
- School of Environmental and Municipal Engineering; Xi'an University of Architecture and Technology; Xi'an China
- Key Lab of Northwest Water Resource, Environment and Ecology; MOE; Xi'an University of Architecture and Technology; Xi'an China
| | - Q.Q. Liu
- School of Environmental and Municipal Engineering; Xi'an University of Architecture and Technology; Xi'an China
- Key Lab of Northwest Water Resource, Environment and Ecology; MOE; Xi'an University of Architecture and Technology; Xi'an China
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Headd B, Bradford SA. Use of aerobic spores as a surrogate for cryptosporidium oocysts in drinking water supplies. WATER RESEARCH 2016; 90:185-202. [PMID: 26734779 DOI: 10.1016/j.watres.2015.12.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 12/10/2015] [Accepted: 12/13/2015] [Indexed: 05/06/2023]
Abstract
Waterborne illnesses are a growing concern among health and regulatory agencies worldwide. The United States Environmental Protection Agency has established several rules to combat the contamination of water supplies by cryptosporidium oocysts, however, the detection and study of cryptosporidium oocysts is hampered by methodological and financial constraints. As a result, numerous surrogates for cryptosporidium oocysts have been proposed by the scientific community and efforts are underway to evaluate many of the proposed surrogates. The purpose of this review is to evaluate the suitability of aerobic bacterial spores to serve as a surrogate for cryptosporidium oocysts in identifying contaminated drinking waters. To accomplish this we present a comparison of the biology and life cycles of aerobic spores and oocysts and compare their physical properties. An analysis of their surface properties is presented along with a review of the literature in regards to the transport, survival, and prevalence of aerobic spores and oocysts in the saturated subsurface environment. Aerobic spores and oocysts share many commonalities with regard to biology and survivability, and the environmental prevalence and ease of detection make aerobic spores a promising surrogate for cryptosporidium oocysts in surface and groundwater. However, the long-term transport and release of aerobic spores still needs to be further studied, and compared with available oocyst information. In addition, the surface properties and environmental interactions of spores are known to be highly dependent on the spore taxa and purification procedures, and additional research is needed to address these issues in the context of transport.
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Affiliation(s)
- Brendan Headd
- U.S. Salinity Lab USDA, ARS, 450 W. Big Springs Road, Riverside, CA 92507-4617, USA
| | - Scott A Bradford
- U.S. Salinity Lab USDA, ARS, 450 W. Big Springs Road, Riverside, CA 92507-4617, USA.
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Microbial analysis of in situ biofilm formation in drinking water distribution systems: implications for monitoring and control of drinking water quality. Appl Microbiol Biotechnol 2015; 100:3301-11. [PMID: 26637423 PMCID: PMC4786615 DOI: 10.1007/s00253-015-7155-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/15/2015] [Accepted: 11/06/2015] [Indexed: 11/15/2022]
Abstract
Biofilm formation in drinking water distribution systems (DWDS) is influenced by the source water, the supply infrastructure and the operation of the system. A holistic approach was used to advance knowledge on the development of mixed species biofilms in situ, by using biofilm sampling devices installed in chlorinated networks. Key physico-chemical parameters and conventional microbial indicators for drinking water quality were analysed. Biofilm coverage on pipes was evaluated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The microbial community structure, bacteria and fungi, of water and biofilms was assessed using pyrosequencing. Conventional wisdom leads to an expectation for less microbial diversity in groundwater supplied systems. However, the analysis of bulk water showed higher microbial diversity in groundwater site samples compared with the surface water site. Conversely, higher diversity and richness were detected in biofilms from the surface water site. The average biofilm coverage was similar among sites. Disinfection residual and other key variables were similar between the two sites, other than nitrates, alkalinity and the hydraulic conditions which were extremely low at the groundwater site. Thus, the unexpected result of an exceptionally low diversity with few dominant genera (Pseudomonas and Basidiobolus) in groundwater biofilm samples, despite the more diverse community in the bulk water, is attributed to the low-flow hydraulic conditions. This finding evidences that the local environmental conditions are shaping biofilm formation, composition and amount, and hence managing these is critical for the best operation of DWDS to safeguard water quality.
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Abstract
Filamentous fungi play an important role not only in the bio-manufacturing of value-added products, but also in bioenergy and environmental research. The bioprocess manipulation of filamentous fungi is more difficult than that of other microbial species because of their different pellet morphologies and the presence of tangled mycelia under different cultivation conditions. Fungal pellets, which have the advantages of harvest ease, low fermentation broth viscosity and high yield of some proteins, have been used for a long time. Many attempts have been made to establish the relationship between pellet and product yield using quantitative approaches. Fungal pellet formation is attributed to the combination of electrostatic interactions, hydrophobicity and specific interactions from spore wall components. Electrostatic interactions result from van der Waals forces and negative charge repulsion from carboxyl groups in the spore wall structure. Electrostatic interactions are also affected by counter-ions (cations) and the physiologic conditions of spores that modify the carboxyl groups. Fungal aggregates are promoted by the hydrophobicity generated by hydrophobins, which form a hydrophobic coat that covers the spore. The specific interactions of spore wall components contribute to spore aggregation through salt bridging. A model of spore aggregation was proposed based on these forces. Additionally, some challenges were addressed, including the limitations of research techniques, the quantitative determination of forces and the complex information of biological systems, to clarify the mechanism of fungal pellet formation.
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Affiliation(s)
- Jianguo Zhang
- a School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology and
| | - Jining Zhang
- b Eco-environmental Protection Research Institute, Shanghai Academy of Agricultural Sciences , Shanghai , China
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UV-induced self-aggregation of E . coli after low and medium pressure ultraviolet irradiation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 148:310-321. [DOI: 10.1016/j.jphotobiol.2015.04.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 04/12/2015] [Accepted: 04/16/2015] [Indexed: 11/20/2022]
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Rao L, Xu Z, Wang Y, Zhao F, Hu X, Liao X. Inactivation of Bacillus subtilis spores by high pressure CO2 with high temperature. Int J Food Microbiol 2015; 205:73-80. [DOI: 10.1016/j.ijfoodmicro.2015.04.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 03/26/2015] [Accepted: 04/05/2015] [Indexed: 10/23/2022]
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Cates SL, Cates EL, Cho M, Kim JH. Synthesis and characterization of visible-to-UVC upconversion antimicrobial ceramics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:2290-7. [PMID: 24533600 DOI: 10.1021/es405229p] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The objective of this study was to develop visible-to-ultraviolet C (UVC) upconversion ceramic materials, which inactivate surface-borne microbes through frequency amplification of ambient visible light. Ceramics were formed by high-temperature sintering of compacted yttrium silicate powders doped with Pr(3+) and Li(+). In comparison to previously reported upconversion surface coatings, the ceramics were significantly more durable and had greater upconversion efficiency under both laser and low-power visible light excitation. The antimicrobial activity of the surfaces under diffuse fluorescent light was assessed by measuring the inactivation of Bacillus subtilis spores, the rate of which was nearly 4 times higher for ceramic materials compared to the previously reported films. Enhanced UVC emissions were attributed to increased material thickness as well as increased crystallite size in the ceramics. These results represent significant advancement of upconversion surfaces for sustainable, light-activated disinfection applications.
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Affiliation(s)
- Stephanie L Cates
- Department of Chemical and Environmental Engineering, Yale University , New Haven, Connecticut 06520-8286, United States
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Lequette Y, Garénaux E, Combrouse T, Dias TDL, Ronse A, Slomianny C, Trivelli X, Guerardel Y, Faille C. Domains of BclA, the major surface glycoprotein of the B. cereus exosporium: glycosylation patterns and role in spore surface properties. BIOFOULING 2011; 27:751-761. [PMID: 21777114 DOI: 10.1080/08927014.2011.599842] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The role of the BclA domains of B. cereus ATCC 14579 was investigated in order to understand the phenomena involved in the interfacial processes occurring between spores and inert surfaces. This was done by (i) creating deletions in the collagen-like region (CLR) and the C-terminal domain (CTD) of BclA, (ii) building BclA proteins with various lengths in the CLR and (iii) modifying the hydrophobic upper surface in the CTD. First, it was demonstrated that the CLR was substituted by three residues already reported in the CLR of B. anthracis, viz. rhamnose, 3-O-methyl-rhamnose, and GalNH(2) residues, while the CTD was also substituted by two additional glycosyl residues, viz. 2-O-methyl-rhamnose and 2,4-O-methyl-rhamnose. Regarding the properties of the spores, both CLR and CTD contributed to the adhesion of the spores, which was estimated by measuring the resistance to detachment of spores adhered to stainless steel plates). CLR and CTD also impacted the hydrophobic character and isoelectric point of the spores. It was then shown that the resistance to detachment of the spores was not affected by the physicochemical properties, but by the CLR length and the presence of hydrophobic amino acids on the CTD.
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Affiliation(s)
- Yannick Lequette
- INRA, UR638 PIHM (Interface Processes and Hygiene of Materials), 369 rue Jules Guesde, F-59651 Villeneuve d'Ascq , France
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Sun J, Zborowski M, Chalmers JJ. Quantification of both the presence, and oxidation state, of Mn in Bacillus atrophaeus spores and its imparting of magnetic susceptibility to the spores. Biotechnol Bioeng 2011; 108:1119-29. [PMID: 21449026 DOI: 10.1002/bit.23034] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2010] [Revised: 11/26/2010] [Accepted: 12/02/2010] [Indexed: 11/11/2022]
Abstract
Bacillus atrophaeus spores were previously reported to have significant magnetic susceptibility in a magnetic field due to the presence of Mn. However, relatively little is known about the total amount and distribution of the oxidation state of Mn associated with this specific strain's spores. Using the instrument, cell tracking velocimetry (CTV) both magnetically induced velocity and settling velocity was quantitatively measured. Visual observations, and calculated diameter using previously reported densities, indicate that the spores are present in the form of clusters of approximately 3-6 µm. Treatment of these clusters with EDTA or pH of 2.0 or below resulted in not only the disruption of the spore clusters, but also a significant decrease in magnetic susceptibility, in some cases by almost two orders of magnitude. Since the magnetic susceptibility of Mn varies significantly between the three typically reported valance states of Mn, Mn(II), Mn(III), and Mn(IV); X-Ray Photoelectron Spectroscopy, XPS, was used to determined the valance states of Mn in the spores. This XPS analysis, which penetrates up to 10 nm into the spore, returned the following fractions: 0.41, 0.38, and 0.21 for the valance states: Mn(II), Mn(III), and Mn(IV), respectively. The total mass of Mn associated with each spore cluster was determined by ICP-MS. A second, completely independent estimate of Mn mass associated with each spore cluster was made, by mathematically solving for the amount of Mn per spore cluster using the experimentally measured magnetophoretic mobility and the magnetic susceptibility of each of the three valence states from the XPS analysis. IPC-MS returned a value of 3.28 × 10(-11) g of Mn per spore cluster while the calculated estimation from mobility and XPS analysis retuned a value of 1.16 × 10(-11) g, which given the complexity of the two techniques, is a reasonable agreement. Finally, a discussion of potential applications of the magnetic properties of these spores is presented.
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Affiliation(s)
- Jianxin Sun
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, USA
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McGovern JP, Shih WH, Rest RF, Purohit M, Mattiucci M, Pourrezaei K, Onaral B, Shih WY. Array lead zirconate titanate/glass piezoelectric microcantilevers for real-time detection of Bacillus anthracis with 10 spores/ml sensitivity and 1/1000 selectivity in bacterial mixtures. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:125104. [PMID: 20059167 PMCID: PMC2802521 DOI: 10.1063/1.3264082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 10/26/2009] [Indexed: 05/28/2023]
Abstract
An array of three identical piezoelectric microcantilever sensors (PEMSs) consisting of a lead zirconate titanate layer bonded to a glass layer was fabricated and examined for simultaneous, in situ, real-time, all-electrical detection of Bacillus anthracis (BA) spores in an aqueous suspension using the first longitudinal extension mode of resonance. With anti-BA antibody immobilized on the sensor surfaces all three PEMS exhibited identical BA detection resonance frequency shifts at all tested concentrations, 10-10(7) spores/ml with a standard deviation of less than 10%. The detection concentration limit of 10 spores/ml was about two orders of magnitude lower than would be permitted by flexural peaks. In blinded-sample testing, the array PEMS detected BA in three samples containing BA: (1) 3.3x10(3) spores/ml, (2) a mixture of 3.3x10(3) spores/ml and 3.3x10(5) S. aureus (SA) and P. aeruginosa (PA) per ml, and (3) a mixture of 3.3x10(3) spores/ml with 3.3x10(6) SA+PA/ml. There was no response to a sample containing only 3.3x10(6) SA+PA/ml. These results illustrate the sensitivity, specificity, reusability, and reliability of array PEMS for in situ, real-time detection of BA spores.
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Affiliation(s)
- John-Paul McGovern
- Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA
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Cartier C, Besner MC, Barbeau B, Lavoie J, Desjardins R, Prévost M. Evaluating aerobic endospores as indicators of intrusion in distribution systems. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/j.1551-8833.2009.tb09923.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Rose LJ, O'Connell H. UV light inactivation of bacterial biothreat agents. Appl Environ Microbiol 2009; 75:2987-90. [PMID: 19270145 PMCID: PMC2681683 DOI: 10.1128/aem.02180-08] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Accepted: 02/25/2009] [Indexed: 11/20/2022] Open
Abstract
Seven species of bacterial biothreat agents were tested for susceptibility to UV light (254 nm). All gram-negative organisms tested required <12 mJ/cm(2) for a 4-log(10) reduction in viability (inactivation). Tailing off of the B. anthracis spore inactivation curves began close to the 2-log(10) inactivation point, with a fluence of approximately 40 mJ/cm(2), and 3-log(10) inactivation still was not achieved with a fluence of 120 mJ/cm(2).
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Affiliation(s)
- L J Rose
- Centers for Disease Control and Prevention, NCID/DHQP/ILB, 1600 Clifton Rd. NE, MS C-16, Atlanta, GA 30329, USA.
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Kearns E, Magaa S, Lim D. Automated concentration and recovery of micro-organisms from drinking water using dead-end ultrafiltration. J Appl Microbiol 2008; 105:432-42. [DOI: 10.1111/j.1365-2672.2008.03757.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bichai F, Payment P, Barbeau B. Protection of waterborne pathogens by higher organisms in drinking water: a review. Can J Microbiol 2008; 54:509-24. [DOI: 10.1139/w08-039] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Higher organisms are ubiquitous in surface waters, and some species can proliferate in granular filters of water treatment plants and colonize distribution systems. Meanwhile, some waterborne pathogens are known to maintain viability inside amoebae or nematodes. The well-documented case of Legionella replication within amoebae is only one example of a bacterial pathogen that can be amplified inside the vacuoles of protozoa and then benefit from the protection of a resistant structure that favours its transport and persistence through water systems. Yet the role of most zooplankton organisms (rotifers, copepods, cladocerans) in pathogen transmission through drinking water remains poorly understood, since their capacity to digest waterborne pathogens has not been well characterized to date. This review aims at (i) evaluating the scientific observations of diverse associations between superior organisms and pathogenic microorganisms in a drinking water perspective and (ii) identifying the missing data that impede the establishment of cause-and-effect relationships that would permit a better appreciation of the sanitary risk arising from such associations. Additional studies are needed to (i) document the occurrence of invertebrate-associated pathogens in relevant field conditions, such as distribution systems; (ii) assess the fate of microorganisms ingested by higher organisms in terms of viability and (or) infectivity; and (iii) study the impact of internalization by zooplankton on pathogen resistance to water disinfection processes, including advanced treatments such as UV disinfection.
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Affiliation(s)
- Françoise Bichai
- NSERC Industrial Chair in Drinking Water, École Polytechnique de Montréal, Department of Civil, Geologic and Mining Engineering, P.O. Box 6079, Succ. Centre Ville, Montréal, QC H3C 3A7, Canada
- INRS – Institut Armand-Frappier, 531 boulevard des Prairies, Laval, QC H7V 1B7, Canada
| | - Pierre Payment
- NSERC Industrial Chair in Drinking Water, École Polytechnique de Montréal, Department of Civil, Geologic and Mining Engineering, P.O. Box 6079, Succ. Centre Ville, Montréal, QC H3C 3A7, Canada
- INRS – Institut Armand-Frappier, 531 boulevard des Prairies, Laval, QC H7V 1B7, Canada
| | - Benoit Barbeau
- NSERC Industrial Chair in Drinking Water, École Polytechnique de Montréal, Department of Civil, Geologic and Mining Engineering, P.O. Box 6079, Succ. Centre Ville, Montréal, QC H3C 3A7, Canada
- INRS – Institut Armand-Frappier, 531 boulevard des Prairies, Laval, QC H7V 1B7, Canada
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Pennell K, Aronson A, Blatchley E. Phenotypic persistence and external shielding ultraviolet radiation inactivation kinetic model. J Appl Microbiol 2008; 104:1192-202. [DOI: 10.1111/j.1365-2672.2007.03645.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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