1
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Kastrat E, Cheng HP. Escherichia coli has an undiscovered ability to inhibit the growth of both Gram-negative and Gram-positive bacteria. Sci Rep 2024; 14:7420. [PMID: 38548840 PMCID: PMC10978900 DOI: 10.1038/s41598-024-57996-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/25/2024] [Indexed: 04/01/2024] Open
Abstract
The ability for bacteria to form boundaries between neighboring colonies as the result of intra-species inhibition has been described for a limited number of species. Here, we report that intra-species inhibition is more common than previously recognized. We demonstrated that swimming colonies of four Escherichia coli strains and six other bacteria form inhibitory zones between colonies, which is not caused by nutrient depletion. This phenomenon was similarly observed with non-flagellated bacteria. We developed a square-streaking pattern assay which revealed that Escherichia coli BW25113 inhibits the growth of other E. coli, and surprisingly, other Gram-positive and negative bacteria, including multi-drug resistant clinical isolates. Altogether, our findings demonstrate intra-species inhibition is common and might be used by E. coli to inhibit other bacteria. Our findings raise the possibility for a common mechanism shared across bacteria for intra-species inhibition. This can be further explored for a potential new class of antibiotics.
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Affiliation(s)
- Ertan Kastrat
- Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY, 10468, USA
- The Graduate Center, City University of New York, New York, NY, 10016, USA
| | - Hai-Ping Cheng
- Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY, 10468, USA.
- The Graduate Center, City University of New York, New York, NY, 10016, USA.
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2
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Eriksen RS, Larsen F, Svenningsen SL, Sneppen K, Mitarai N. The dynamics of phage predation on a microcolony. Biophys J 2024; 123:147-156. [PMID: 38069473 PMCID: PMC10808037 DOI: 10.1016/j.bpj.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 10/23/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023] Open
Abstract
Phage predation is an important factor for controlling the bacterial biomass. At face value, dense microbial habitats are expected to be vulnerable to phage epidemics due to the abundance of fresh hosts immediately next to any infected bacteria. Despite this, the bacterial microcolony is a common habitat for bacteria in nature. Here, we experimentally quantify the fate of microcolonies of Escherichia coli exposed to virulent phage T4. It has been proposed that the outer bacterial layers of the colony will shield the inner layers from the phage invasion and thereby constrain the phage to the colony's surface. We develop a dynamical model that incorporates this shielding mechanism and fit the results with experimental measurements to extract important phage-bacteria interaction parameters. The analysis suggests that, while the shielding mechanism delays phage attack, T4 phage are able to diffuse so deep into the dense bacterial environment that colony-level survival of the bacterial community is challenged.
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Affiliation(s)
- Rasmus Skytte Eriksen
- The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark; Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Frej Larsen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark; Department of Food Science, University of Copenhagen, Copenhagen, Denmark
| | | | - Kim Sneppen
- The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Namiko Mitarai
- The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
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3
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Purk L, Kitsiou M, Ioannou C, El Kadri H, Costello KM, Gutierrez Merino J, Klymenko O, Velliou EG. Unravelling the impact of fat content on the microbial dynamics and spatial distribution of foodborne bacteria in tri-phasic viscoelastic 3D models. Sci Rep 2023; 13:21811. [PMID: 38071223 PMCID: PMC10710490 DOI: 10.1038/s41598-023-48968-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/02/2023] [Indexed: 12/18/2023] Open
Abstract
The aim of the current study is to develop and characterise novel complex multi-phase in vitro 3D models, for advanced microbiological studies. More specifically, we enriched our previously developed bi-phasic polysaccharide (Xanthan Gum)/protein (Whey Protein) 3D model with a fat phase (Sunflower Oil) at various concentrations, i.e., 10%, 20%, 40% and 60% (v/v), for better mimicry of the structural and biochemical composition of real food products. Rheological, textural, and physicochemical analysis as well as advanced microscopy imaging (including spatial mapping of the fat droplet distribution) of the new tri-phasic 3D models revealed their similarity to industrial food products (especially cheese products). Furthermore, microbial growth experiments of foodborne bacteria, i.e., Listeria monocytogenes, Escherichia coli, Pseudomonas aeruginosa and Lactococcus lactis on the surface of the 3D models revealed very interesting results, regarding the growth dynamics and distribution of cells at colony level. More specifically, the size of the colonies formed on the surface of the 3D models, increased substantially for increasing fat concentrations, especially in mid- and late-exponential growth phases. Furthermore, colonies formed in proximity to fat were substantially larger as compared to the ones that were located far from the fat phase of the models. In terms of growth location, the majority of colonies were located on the protein/polysaccharide phase of the 3D models. All those differences at microscopic level, that can directly affect the bacterial response to decontamination treatments, were not captured by the macroscopic kinetics (growth dynamics), which were unaffected from changes in fat concentration. Our findings demonstrate the importance of developing structurally and biochemically complex 3D in vitro models (for closer proximity to industrial products), as well as the necessity of conducting multi-level microbial analyses, to better understand and predict the bacterial behaviour in relation to their biochemical and structural environment. Such studies in advanced 3D environments can assist a better/more accurate design of industrial antimicrobial processes, ultimately, improving food safety.
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Affiliation(s)
- Lisa Purk
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering, University of Surrey, Guildford, GU2 7XH, UK
- Centre for 3D Models of Health and Disease, Division of Surgery and Interventional Science, University College London, Charles Bell House, 43-45 Foley Street, Fitzrovia, London, W1W 7TY, UK
| | - Melina Kitsiou
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering, University of Surrey, Guildford, GU2 7XH, UK
- Centre for 3D Models of Health and Disease, Division of Surgery and Interventional Science, University College London, Charles Bell House, 43-45 Foley Street, Fitzrovia, London, W1W 7TY, UK
| | - Christina Ioannou
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering, University of Surrey, Guildford, GU2 7XH, UK
| | - Hani El Kadri
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering, University of Surrey, Guildford, GU2 7XH, UK
| | - Katherine M Costello
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering, University of Surrey, Guildford, GU2 7XH, UK
| | | | - Oleksiy Klymenko
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering, University of Surrey, Guildford, GU2 7XH, UK
| | - Eirini G Velliou
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering, University of Surrey, Guildford, GU2 7XH, UK.
- Centre for 3D Models of Health and Disease, Division of Surgery and Interventional Science, University College London, Charles Bell House, 43-45 Foley Street, Fitzrovia, London, W1W 7TY, UK.
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4
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Rothschild J, Ma T, Milstein JN, Zilman A. Spatial exclusion leads to "tug-of-war" ecological dynamics between competing species within microchannels. PLoS Comput Biol 2023; 19:e1010868. [PMID: 38039342 PMCID: PMC10718426 DOI: 10.1371/journal.pcbi.1010868] [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: 01/10/2023] [Revised: 12/13/2023] [Accepted: 11/07/2023] [Indexed: 12/03/2023] Open
Abstract
Competition is ubiquitous in microbial communities, shaping both their spatial and temporal structure and composition. Classical minimal models of competition, such as the Moran model, have been employed in ecology and evolutionary biology to understand the role of fixation and invasion in the maintenance of population diversity. Informed by recent experimental studies of cellular competition in confined spaces, we extend the Moran model to incorporate mechanical interactions between cells that divide within the limited space of a one-dimensional open microchannel. The model characterizes the skewed collective growth of the cells dividing within the channel, causing cells to be expelled at the channel ends. The results of this spatial exclusion model differ significantly from those of its classical well-mixed counterpart. The mean time to fixation of a species is greatly accelerated, scaling logarithmically, rather than algebraically, with the system size, and fixation/extinction probability sharply depends on the species' initial fractional abundance. By contrast, successful takeovers by invasive species, whether through mutation or immigration, are substantially less likely than in the Moran model. We also find that the spatial exclusion tends to attenuate the effects of fitness differences on the fixation times and probabilities. We find that these effects arise from the combination of the quasi-neutral "tug-of-war" diffusion dynamics of the inter-species boundary around an unstable equipoise point and the quasi-deterministic avalanche dynamics away from the fixed point. These results, which can be tested in microfluidic monolayer devices, have implications for the maintenance of species diversity in dense bacterial and cellular ecosystems where spatial exclusion is central to the competition, such as in organized biofilms or intestinal crypts.
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Affiliation(s)
| | - Tianyi Ma
- Department of Physics, University of Toronto, Ontario, Canada
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Ontario, Canada
| | - Joshua N. Milstein
- Department of Physics, University of Toronto, Ontario, Canada
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Ontario, Canada
| | - Anton Zilman
- Department of Physics, University of Toronto, Ontario, Canada
- Institute for Biomedical Engineering, University of Toronto, Ontario, Canada
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5
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Wang Z, Ishii S, Novak PJ. Quantification of depth-dependent microbial growth in encapsulated systems. Microb Biotechnol 2023; 16:2094-2104. [PMID: 37750468 PMCID: PMC10616645 DOI: 10.1111/1751-7915.14341] [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: 07/06/2023] [Revised: 08/26/2023] [Accepted: 09/01/2023] [Indexed: 09/27/2023] Open
Abstract
Encapsulated systems have been widely used in environmental applications to selectively retain and protect microorganisms. The permeable matrix used for encapsulation, however, limits the accessibility of existing analytical methods to study the behaviour of the encapsulated microorganisms. Here, we present a novel method that overcomes these limitations and enables direct observation and enumeration of encapsulated microbial colonies over a range of spatial and temporal scales. The method involves embedding, cross-sectioning, and analysing the system via fluorescence in situ hybridization and retains the structure of encapsulants and the morphology of encapsulated colonies. The major novelty of this method lies in its ability to distinguish between, and subsequently analyse, multiple microorganisms within a single encapsulation matrix across depth. Our results demonstrated the applicability and repeatability of this method with alginate-encapsulated pure (Nitrosomonas europaea) and enrichment cultures (anammox enrichment). The use of this method can potentially reveal interactions between encapsulated microorganisms and their surrounding matrix, as well as quantitatively validate predictions from mathematical models, thereby advancing our understanding of microbial ecology in encapsulated or even biofilm systems and facilitating the optimization of these systems.
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Affiliation(s)
- Zhiyue Wang
- Department of Civil and Environmental EngineeringUniversity of Hawai'iHonoluluHawai'iUSA
- Water Resources Research CenterUniversity of Hawai'iHonoluluHawai'iUSA
- BioTechnology InstituteUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Satoshi Ishii
- BioTechnology InstituteUniversity of MinnesotaSt. PaulMinnesotaUSA
- Department of Soil, Water and ClimateUniversity of MinnesotaSt. PaulMinnesotaUSA
| | - Paige J. Novak
- BioTechnology InstituteUniversity of MinnesotaSt. PaulMinnesotaUSA
- Department of Civil, Environmental, and Geo‐EngineeringUniversity of Minnesota, MinneapolisMinnesotaUSA
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6
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Reis MM, Dixit Y, Carr A, Tu C, Palevich F, Gupta T, Reis MG. Hyperspectral imaging through vacuum packaging for monitoring cheese biochemical transformation caused by Clostridium metabolism. Food Res Int 2023; 169:112866. [PMID: 37254314 DOI: 10.1016/j.foodres.2023.112866] [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: 11/10/2022] [Revised: 04/15/2023] [Accepted: 04/18/2023] [Indexed: 06/01/2023]
Abstract
This study developed a novel method for monitoring cheese contamination with Clostridium spores non-invasively using hyperspectral imaging (HSI). The ability of HSI to quantify Clostridium metabolites was investigated with control cheese and cheese manufactured with milk contaminated with Clostridium tyrobutyricum, Clostridium butyricum and Clostridium sporogenes. Microbial count, HSI and SPME-GC-MS data were obtained over 10 weeks of storage. The developed method using HSI successfully quantified butyric acid (R2 = 0.91, RPD = 3.38) a major compound of Clostridium metabolism in cheese. This study creates a new venue to monitor the spatial and temporal development of late blowing defect (LBD) in cheese using fast and non-invasive measurement.
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Affiliation(s)
- Marlon M Reis
- AgResearch, Te Ohu Rangahau Kai, Palmerston North 4474, New Zealand.
| | - Yash Dixit
- AgResearch, Te Ohu Rangahau Kai, Palmerston North 4474, New Zealand
| | - Alistair Carr
- AgResearch, Te Ohu Rangahau Kai, Palmerston North 4474, New Zealand
| | - Christine Tu
- AgResearch, Te Ohu Rangahau Kai, Palmerston North 4474, New Zealand
| | - Faith Palevich
- AgResearch, Te Ohu Rangahau Kai, Palmerston North 4474, New Zealand
| | - Tanushree Gupta
- AgResearch, Te Ohu Rangahau Kai, Palmerston North 4474, New Zealand
| | - Mariza G Reis
- AgResearch, Te Ohu Rangahau Kai, Palmerston North 4474, New Zealand
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7
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Nguyen-Le TA, Zhao X, Bachmann M, Ruelens P, de Visser JAGM, Baraban L. High-Throughput Gel Microbeads as Incubators for Bacterial Competition Study. MICROMACHINES 2023; 14:645. [PMID: 36985052 PMCID: PMC10058504 DOI: 10.3390/mi14030645] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 03/07/2023] [Accepted: 03/09/2023] [Indexed: 06/18/2023]
Abstract
Bacteria primarily live in structured environments, such as colonies and biofilms, attached to surfaces or growing within soft tissues. They are engaged in local competitive and cooperative interactions impacting our health and well-being, for example, by affecting population-level drug resistance. Our knowledge of bacterial competition and cooperation within soft matrices is incomplete, partly because we lack high-throughput tools to quantitatively study their interactions. Here, we introduce a method to generate a large amount of agarose microbeads that mimic the natural culture conditions experienced by bacteria to co-encapsulate two strains of fluorescence-labeled Escherichia coli. Focusing specifically on low bacterial inoculum (1-100 cells/capsule), we demonstrate a study on the formation of colonies of both strains within these 3D scaffolds and follow their growth kinetics and interaction using fluorescence microscopy in highly replicated experiments. We confirmed that the average final colony size is inversely proportional to the inoculum size in this semi-solid environment as a result of limited available resources. Furthermore, the colony shape and fluorescence intensity per colony are distinctly different in monoculture and co-culture. The experimental observations in mono- and co-culture are compared with predictions from a simple growth model. We suggest that our high throughput and small footprint microbead system is an excellent platform for future investigation of competitive and cooperative interactions in bacterial communities under diverse conditions, including antibiotics stress.
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Affiliation(s)
- Trang Anh Nguyen-Le
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf e. V. (HZDR), 01328 Dresden, Germany
| | - Xinne Zhao
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf e. V. (HZDR), 01328 Dresden, Germany
| | - Michael Bachmann
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf e. V. (HZDR), 01328 Dresden, Germany
- Tumor Immunology, University Cancer Center (UCC), University Hospital Carl Gustav Carus Dresden, Technische Universität Dresden, 01307 Dresden, Germany
- National Center for Tumor Diseases (NCT), Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307 Dresden, Germany
- German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- German Cancer Consortium (DKTK), 01309 Dresden, Germany
| | - Philip Ruelens
- Department of Genetics, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - J. Arjan G. M. de Visser
- Department of Genetics, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Larysa Baraban
- Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf e. V. (HZDR), 01328 Dresden, Germany
- Center for Advancing Electronics Dresden (cfaed), Technische Universität Dresden, 01069 Dresden, Germany
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8
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Balmages I, Liepins J, Auzins ET, Bliznuks D, Baranovics E, Lihacova I, Lihachev A. Use of the speckle imaging sub-pixel correlation analysis in revealing a mechanism of microbial colony growth. Sci Rep 2023; 13:2613. [PMID: 36788263 PMCID: PMC9929235 DOI: 10.1038/s41598-023-29809-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
The microbial colony growth is driven by the activity of the cells located on the edges of the colony. However, this process is not visible unless specific staining or cross-sectioning of the colony is done. Speckle imaging technology is a non-invasive method that allows visualization of the zones of increased microbial activity within the colony. In this study, the laser speckle imaging technique was used to record the growth of the microbial colonies. This method was tested on three different microorganisms: Vibrio natriegens, Escherichia coli, and Staphylococcus aureus. The results showed that the speckle analysis system is not only able to record the growth of the microbial colony but also to visualize the microbial growth activity in different parts of the colony. The developed speckle imaging technique visualizes the zone of "the highest microbial activity" migrating from the center to the periphery of the colony. The results confirm the accuracy of the previous models of colony growth and provide algorithms for analysis of microbial activity within the colony.
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Affiliation(s)
- Ilya Balmages
- Faculty of Computer Science and Information Technology, Department of Computer Control and Computer Networks, Riga Technical University, Zunda Krastmala 10, LV-1048, Riga, Latvia.
- Laboratorija Auctoritas Ltd, Čiekurkalna 1. linija 11, Riga, LV-1026, Latvia.
| | - Janis Liepins
- Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas str. 1, Riga, LV-1004, Latvia
| | - Ernests Tomass Auzins
- Laboratorija Auctoritas Ltd, Čiekurkalna 1. linija 11, Riga, LV-1026, Latvia
- Institute of Microbiology and Biotechnology, University of Latvia, Jelgavas str. 1, Riga, LV-1004, Latvia
| | - Dmitrijs Bliznuks
- Faculty of Computer Science and Information Technology, Department of Computer Control and Computer Networks, Riga Technical University, Zunda Krastmala 10, LV-1048, Riga, Latvia
| | - Edgars Baranovics
- Laboratorija Auctoritas Ltd, Čiekurkalna 1. linija 11, Riga, LV-1026, Latvia
| | - Ilze Lihacova
- Institute of Atomic Physics and Spectroscopy, University of Latvia, Jelgavas str. 3, Riga, LV-1004, Latvia
| | - Alexey Lihachev
- Institute of Atomic Physics and Spectroscopy, University of Latvia, Jelgavas str. 3, Riga, LV-1004, Latvia
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9
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Asada R, Yamada Y, Sakamoto JJ, Furuta M, Tsuchido T. Theory and application of growth delay analysis of colony formation for evaluation of injured population of the stressed fungal conidia. JOURNAL OF MICROORGANISM CONTROL 2023; 28:93-100. [PMID: 37866901 DOI: 10.4265/jmc.28.3_93] [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: 10/24/2023]
Abstract
A new concept of injured population assessment is proposed, in which the size of the injured population in stressed mold spores is evaluated by analyzing the colony formation process on a solid agar medium. In this method, a small paper disc containing mold spores is placed on a subculture agar plate, and the linear increase in the radius of the colony formed by development from the spore is measured over time. Then, the principle of the previously reported growth delay analysis (GDA) method originally using a liquid medium is applied to obtain the integrated viable ratio (IV) of the stressed population from the delay time relative to the growth of the unstressed population. On the other hand, the viable ratio (V) to the initial value as the colony count obtained with the stressed culture is obtained; the difference between the logarithms of V and IV is determined as the log number of the injured population. Applying this analysis method to heated spores of Cladosporium sphaerospermum, we determined the size of the injured population that occurred. This method was considered to be effective as a new method for quantifying injured populations using a solid medium.
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Affiliation(s)
- Ryoko Asada
- Research Center of Microorganism Control, Organization for Research Promotion, Osaka Prefecture University
- Department of Quantum and Radiation Engineering, Graduate School of Engineering, Osaka Prefecture University
| | - Yoshie Yamada
- Research Center of Microorganism Control, Organization for Research Promotion, Osaka Prefecture University
| | - Jin J Sakamoto
- Research Center of Microorganism Control, Organization for Research Promotion, Osaka Prefecture University
- MPES-3U and Faculty of Materials, Chemistry and Biotechnology, Kansai University
| | - Masakazu Furuta
- Research Center of Microorganism Control, Organization for Research Promotion, Osaka Prefecture University
- Department of Quantum and Radiation Engineering, Graduate School of Engineering, Osaka Prefecture University
| | - Tetsuaki Tsuchido
- Research Center of Microorganism Control, Organization for Research Promotion, Osaka Prefecture University
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10
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The Antimicrobial Effect of Various Single-Strain and Multi-Strain Probiotics, Dietary Supplements or Other Beneficial Microbes against Common Clinical Wound Pathogens. Microorganisms 2022; 10:microorganisms10122518. [PMID: 36557771 PMCID: PMC9781324 DOI: 10.3390/microorganisms10122518] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
The skin is the largest organ in the human body and is colonized by a diverse microbiota that works in harmony to protect the skin. However, when skin damage occurs, the skin microbiota is also disrupted, and pathogens can invade the wound and cause infection. Probiotics or other beneficial microbes and their metabolites are one possible alternative treatment for combating skin pathogens via their antimicrobial effectiveness. The objective of our study was to evaluate the antimicrobial effect of seven multi-strain dietary supplements and eleven single-strain microbes that contain probiotics against 15 clinical wound pathogens using the agar spot assay, co-culturing assay, and agar well diffusion assay. We also conducted genera-specific and species-specific molecular methods to detect the DNA in the dietary supplements and single-strain beneficial microbes. We found that the multi-strain dietary supplements exhibited a statistically significant higher antagonistic effect against the challenge wound pathogens than the single-strain microbes and that lactobacilli-containing dietary supplements and single-strain microbes were significantly more efficient than the selected propionibacteria and bacilli. Differences in results between methods were also observed, possibly due to different mechanisms of action. Individual pathogens were susceptible to different dietary supplements or single-strain microbes. Perhaps an individual approach such as a 'probiogram' could be a possibility in the future as a method to find the most efficient targeted probiotic strains, cell-free supernatants, or neutralized cell-free supernatants that have the highest antagonistic effect against individual clinical wound pathogens.
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11
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Mahilkar A, Raj N, Kemkar S, Saini S. Selection in a growing colony biases results of mutation accumulation experiments. Sci Rep 2022; 12:15470. [PMID: 36104390 PMCID: PMC9475022 DOI: 10.1038/s41598-022-19928-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 09/06/2022] [Indexed: 11/11/2022] Open
Abstract
Mutations provide the raw material for natural selection to act. Therefore, understanding the variety and relative frequency of different type of mutations is critical to understanding the nature of genetic diversity in a population. Mutation accumulation (MA) experiments have been used in this context to estimate parameters defining mutation rates, distribution of fitness effects (DFE), and spectrum of mutations. MA experiments can be performed with different effective population sizes. In MA experiments with bacteria, a single founder is grown to a size of a colony (~ 108). It is assumed that natural selection plays a minimal role in dictating the dynamics of colony growth. In this work, we simulate colony growth via a mathematical model, and use our model to mimic an MA experiment. We demonstrate that selection ensures that, in an MA experiment, fraction of all mutations that are beneficial is over-represented by a factor of almost two, and that the distribution of fitness effects of beneficial and deleterious mutations are inaccurately captured in an MA experiment. Given this, the estimate of mutation rates from MA experiments is non-trivial. We then perform an MA experiment with 160 lines of E. coli, and show that due to the effect of selection in a growing colony, the size and sector of a colony from which the experiment is propagated impacts the results. Overall, we demonstrate that the results of MA experiments need to be revisited taking into account the action of selection in a growing colony.
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Affiliation(s)
- Anjali Mahilkar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Namratha Raj
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Sharvari Kemkar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Supreet Saini
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
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12
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Martin CS, Jubelin G, Darsonval M, Leroy S, Leneveu-Jenvrin C, Hmidene G, Omhover L, Stahl V, Guillier L, Briandet R, Desvaux M, Dubois-Brissonnet F. Genetic, physiological, and cellular heterogeneities of bacterial pathogens in food matrices: Consequences for food safety. Compr Rev Food Sci Food Saf 2022; 21:4294-4326. [PMID: 36018457 DOI: 10.1111/1541-4337.13020] [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: 03/22/2022] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 01/28/2023]
Abstract
In complex food systems, bacteria live in heterogeneous microstructures, and the population displays phenotypic heterogeneities at the single-cell level. This review provides an overview of spatiotemporal drivers of phenotypic heterogeneity of bacterial pathogens in food matrices at three levels. The first level is the genotypic heterogeneity due to the possibility for various strains of a given species to contaminate food, each of them having specific genetic features. Then, physiological heterogeneities are induced within the same strain, due to specific microenvironments and heterogeneous adaptative responses to the food microstructure. The third level of phenotypic heterogeneity is related to cellular heterogeneity of the same strain in a specific microenvironment. Finally, we consider how these phenotypic heterogeneities at the single-cell level could be implemented in mathematical models to predict bacterial behavior and help ensure microbiological food safety.
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Affiliation(s)
- Cédric Saint Martin
- MICALIS Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, France.,Université Clermont Auvergne, INRAE, UMR454 MEDIS, Clermont-Ferrand, France
| | - Grégory Jubelin
- Université Clermont Auvergne, INRAE, UMR454 MEDIS, Clermont-Ferrand, France
| | - Maud Darsonval
- MICALIS Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, France
| | - Sabine Leroy
- Université Clermont Auvergne, INRAE, UMR454 MEDIS, Clermont-Ferrand, France
| | - Charlène Leneveu-Jenvrin
- MICALIS Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, France.,Association pour le Développement de l'Industrie de la Viande (ADIV), Clermont-Ferrand, France
| | - Ghaya Hmidene
- Risk Assessment Department, ANSES, Maisons-Alfort, France
| | - Lysiane Omhover
- Aerial, Technical Institute of Agro-Industry, Illkirch, France
| | - Valérie Stahl
- Aerial, Technical Institute of Agro-Industry, Illkirch, France
| | | | - Romain Briandet
- MICALIS Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, France
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRAE, UMR454 MEDIS, Clermont-Ferrand, France
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13
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Membrane Technology for Valorization of Mango Peel Extracts. Foods 2022; 11:foods11172581. [PMID: 36076767 PMCID: PMC9455947 DOI: 10.3390/foods11172581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/17/2022] [Accepted: 08/23/2022] [Indexed: 11/18/2022] Open
Abstract
Mango peel is rich in nutritional and functional compounds, such as carbohydrates, dietary fibers, proteins, and phenolic compounds, with high potential to be applied in the food industry. Most of the investigation about recovery of bioactive compounds from fruit bioproducts involves extraction techniques and further separation of target compounds. There is still a lack of information about the potential of membrane processes to recover the nutritive/functional compounds present in aqueous extracts of those bioproducts. This research is addressed to study the performance of ultrafiltration (UF), followed by nanofiltration (NF) of UF permeates, to fractionate the compounds present in aqueous extracts of mango peel. Both UF and NF concentration processes were carried up to a volume concentration factor of 2.0. Membranes with molecular weight cut-offs of 25 kDa and 130 Da were used in the UF and NF steps, respectively. UF and NF concentrates showed antioxidant activity, attributed to the presence of phenolic compounds, with rejections of about 75% and 98.8%, respectively. UF membranes totally rejected the higher molecular weight compounds, and NF membranes almost totally concentrated the fermentable monosaccharides and disaccharides. Therefore, it is envisaged that NF concentrates can be utilized by the food industry or for bioenergy production.
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14
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Hitomi K, Weng J, Ying BW. Contribution of the genomic and nutritional differentiation to the spatial distribution of bacterial colonies. Front Microbiol 2022; 13:948657. [PMID: 36081803 PMCID: PMC9448356 DOI: 10.3389/fmicb.2022.948657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
Colony growth is a common phenomenon of structured populations dispersed in nature; nevertheless, studies on the spatial distribution of colonies are largely insufficient. Here, we performed a systematic survey to address the questions of whether and how the spatial distribution of colonies was influenced by the genome and environment. Six Escherichia coli strains carrying either the wild-type or reduced genomes and eight media of varied nutritional richness were used to evaluate the genomic and environmental impacts, respectively. The genome size and nutritional variation contributed to the mean size and total area but not the variation and shape of size distribution of the colonies formed within the identical space and of equivalent spatial density. The spatial analysis by means of the Voronoi diagram found that the Voronoi correlation remained nearly constant in common, in comparison to the Voronoi response decreasing in correlation to genome reduction and nutritional enrichment. Growth analysis at the single colony level revealed positive correlations of the relative growth rate to both the maximal colony size and the Voronoi area, regardless of the genomic and nutritional variety. This result indicated fast growth for the large space assigned and supported homeostasis in the Voronoi correlation. Taken together, the spatial distribution of colonies might benefit efficient clonal growth. Although the mechanisms remain unclear, the findings provide quantitative insights into the genomic and environmental contributions to the growth and distribution of spatially or geographically isolated populations.
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15
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Liu X, Wang Z, Xiao J, Zhou X, Xu Y. Osmotic stress tolerance and transcriptome analysis of Gluconobacter oxydans to extra-high titers of glucose. Front Microbiol 2022; 13:977024. [PMID: 36033857 PMCID: PMC9412170 DOI: 10.3389/fmicb.2022.977024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 07/26/2022] [Indexed: 11/13/2022] Open
Abstract
Gluconobacter oxydans has been widely acknowledged as an ideal strain for industrial bio-oxidations with fantastic yield and productivity. Even 600 g/L xylose can be catalyzed efficiently in a sealed and compressed oxygen-supplying bioreactor. Therefore, the present study seeks to explore the osmotic stress tolerance against extra-high titer of representative lignocellulosic sugars like glucose. Gluconobacter oxydans can well adapted and fermented with initial 600 g/L glucose, exhibiting the highest bio-tolerance in prokaryotic strains and the comparability to the eukaryotic strain of Saccharomyces cerevisiae. 1,432 differentially expressed genes corresponding to osmotic pressure are detected through transcriptome analysis, involving several genes related to the probable compatible solutes (trehalose and arginine). Gluconobacter oxydans obtains more energy by enhancing the substrate-level phosphorylation, resulting in the increased glucose consumption rate after fermentation adaption phase. This study will provide insights into further investigation of biological tolerance and response to extra-high titers of glucose of G. oxydans.
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Affiliation(s)
- Xinlu Liu
- Key Laboratory of Forestry Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, China
| | - Zhiwei Wang
- Key Laboratory of Forestry Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, China
| | - Jianjian Xiao
- Key Laboratory of Forestry Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, China
| | - Xin Zhou
- Key Laboratory of Forestry Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, China
| | - Yong Xu
- Key Laboratory of Forestry Genetics and Biotechnology, Ministry of Education, Nanjing Forestry University, Nanjing, China
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, China
- Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals, Nanjing, China
- *Correspondence: Yong Xu,
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16
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Borges F, Briandet R, Callon C, Champomier-Vergès MC, Christieans S, Chuzeville S, Denis C, Desmasures N, Desmonts MH, Feurer C, Leroi F, Leroy S, Mounier J, Passerini D, Pilet MF, Schlusselhuber M, Stahl V, Strub C, Talon R, Zagorec M. Contribution of omics to biopreservation: Toward food microbiome engineering. Front Microbiol 2022; 13:951182. [PMID: 35983334 PMCID: PMC9379315 DOI: 10.3389/fmicb.2022.951182] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/14/2022] [Indexed: 01/12/2023] Open
Abstract
Biopreservation is a sustainable approach to improve food safety and maintain or extend food shelf life by using beneficial microorganisms or their metabolites. Over the past 20 years, omics techniques have revolutionised food microbiology including biopreservation. A range of methods including genomics, transcriptomics, proteomics, metabolomics and meta-omics derivatives have highlighted the potential of biopreservation to improve the microbial safety of various foods. This review shows how these approaches have contributed to the selection of biopreservation agents, to a better understanding of the mechanisms of action and of their efficiency and impact within the food ecosystem. It also presents the potential of combining omics with complementary approaches to take into account better the complexity of food microbiomes at multiple scales, from the cell to the community levels, and their spatial, physicochemical and microbiological heterogeneity. The latest advances in biopreservation through omics have emphasised the importance of considering food as a complex and dynamic microbiome that requires integrated engineering strategies to increase the rate of innovation production in order to meet the safety, environmental and economic challenges of the agri-food sector.
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Affiliation(s)
- Frédéric Borges
- Université de Lorraine, LIBio, Nancy, France
- *Correspondence: Frédéric Borges,
| | - Romain Briandet
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Cécile Callon
- Université Clermont Auvergne, INRAE, VetAgro Sup, UMR 545 Fromage, Aurillac, France
| | | | | | - Sarah Chuzeville
- ACTALIA, Pôle d’Expertise Analytique, Unité Microbiologie Laitière, La Roche sur Foron, France
| | | | | | | | - Carole Feurer
- IFIP, Institut de la Filière Porcine, Le Rheu, France
| | | | - Sabine Leroy
- Université Clermont Auvergne, INRAE, MEDIS, Clermont-Ferrand, France
| | - Jérôme Mounier
- Univ Brest, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, Plouzané, France
| | | | | | | | | | - Caroline Strub
- Qualisud, Univ Montpellier, Avignon Université, CIRAD, Institut Agro, IRD, Université de La Réunion, Montpellier, France
| | - Régine Talon
- Université Clermont Auvergne, INRAE, MEDIS, Clermont-Ferrand, France
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17
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Saint Martin C, Darsonval M, Grégoire M, Caccia N, Midoux L, Berland S, Leroy S, Dubois-Brissonnet F, Desvaux M, Briandet R. Spatial organisation of Listeria monocytogenes and Escherichia coli O157:H7 cultivated in gel matrices. Food Microbiol 2022; 103:103965. [DOI: 10.1016/j.fm.2021.103965] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 01/01/2023]
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18
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Biofilm through the Looking Glass: A Microbial Food Safety Perspective. Pathogens 2022; 11:pathogens11030346. [PMID: 35335670 PMCID: PMC8954374 DOI: 10.3390/pathogens11030346] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/08/2022] [Accepted: 03/10/2022] [Indexed: 02/06/2023] Open
Abstract
Food-processing facilities harbor a wide diversity of microorganisms that persist and interact in multispecies biofilms, which could provide an ecological niche for pathogens to better colonize and gain tolerance against sanitization. Biofilm formation by foodborne pathogens is a serious threat to food safety and public health. Biofilms are formed in an environment through synergistic interactions within the microbial community through mutual adaptive response to their long-term coexistence. Mixed-species biofilms are more tolerant to sanitizers than single-species biofilms or their planktonic equivalents. Hence, there is a need to explore how multispecies biofilms help in protecting the foodborne pathogen from common sanitizers and disseminate biofilm cells from hotspots and contaminate food products. This knowledge will help in designing microbial interventions to mitigate foodborne pathogens in the processing environment. As the global need for safe, high-quality, and nutritious food increases, it is vital to study foodborne pathogen behavior and engineer new interventions that safeguard food from contamination with pathogens. This review focuses on the potential food safety issues associated with biofilms in the food-processing environment.
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19
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Chromiková Z, Chovanová RK, Tamindžija D, Bártová B, Radnović D, Bernier-Latmani R, Barák I. Implantation of Bacillus pseudomycoides Chromate Transporter Increases Chromate Tolerance in Bacillus subtilis. Front Microbiol 2022; 13:842623. [PMID: 35330768 PMCID: PMC8940164 DOI: 10.3389/fmicb.2022.842623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 02/14/2022] [Indexed: 11/23/2022] Open
Abstract
Chromium of anthropogenic origin contaminates the environment worldwide. The toxicity of chromium, a group I human carcinogen, is greatest when it is in a hexavalent oxidation state, Cr(VI). Cr(VI) is actively transported into the cell, triggering oxidative damage intracellularly. Due to the abundance of unspecific intracellular reductants, any microbial species is capable of bio-transformation of toxic Cr(VI) to innocuous Cr(III), however, this process is often lethal. Only some bacterial species are capable of sustaining the vegetative growth in the presence of a high concentration of Cr(VI) and thus operate as self-sustainable bioremediation agents. One of the successful microbial Cr(VI) detoxification strategies is the activation of chromate efflux pumps. This work describes transplantation of the chromate efflux pump from the potentially pathogenic but highly Cr resistant Bacillus pseudomycoides environmental strain into non-pathogenic but only transiently Cr tolerant Bacillus subtilis strain. In our study, we compared the two Bacillus spp. strains harboring evolutionarily diverged chromate efflux proteins. We have found that individual cells of the Cr-resistant B. pseudomycoides environmental strain accumulate less Cr than the cells of B. subtilis strain. Further, we found that survival of the B. subtilis strain during the Cr stress can be increased by the introduction of the chromate transporter from the Cr resistant environmental strain into its genome. Additionally, the expression of B. pseudomycoides chromate transporter ChrA in B. subtilis seems to be activated by the presence of chromate, hinting at versatility of Cr-efflux proteins. This study outlines the future direction for increasing the Cr-tolerance of non-pathogenic species and safe bioremediation using soil bacteria.
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Affiliation(s)
- Zuzana Chromiková
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
- *Correspondence: Zuzana Chromiková,
| | - Romana Kalianková Chovanová
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Dragana Tamindžija
- Department of Chemistry, Faculty of Sciences, Biochemistry and Environmental Protection, Novi Sad, Serbia
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Barbora Bártová
- Environmental Microbiology Laboratory, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Dragan Radnović
- Department of Biology and Ecology, Faculty of Sciences, University of Novi Sad, Novi Sad, Serbia
| | - Rizlan Bernier-Latmani
- Environmental Microbiology Laboratory, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Imrich Barák
- Department of Microbial Genetics, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava, Slovakia
- Imrich Barák,
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20
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Rachmawati N, Powell SM, Triwibowo R, Nichols DS, Ross T, Tamplin ML. Modelling growth and histamine formation of Klebsiella aerogenes TI24 isolated from Indonesian pindang. Int J Food Microbiol 2022; 362:109459. [PMID: 34861562 DOI: 10.1016/j.ijfoodmicro.2021.109459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 09/24/2021] [Accepted: 10/24/2021] [Indexed: 10/20/2022]
Abstract
Indonesian salted-boiled fish (pindang) is a popular traditional food in Indonesia, which is made from Scombroid fish such as tuna and mackerel. As with other traditionally prepared fish products, pindang has important economic and social values, especially for those living in the coastal areas of Indonesia. However, pindang is a major cause of histamine fish poisoning (HFP) for consumers. Klebsiella aerogenes T124, a relatively high histamine-producing isolate from pindang, was used to describe lag time (λ), growth rate (μmax), maximum population density (Nmax), and histamine production in histidine broth and artificially contaminated Grey mackerel. Broth was adjusted to 1.5, 6, 10 and 20% w/v NaCl; mackerel was treated with 6% w/w NaCl, a level common to Indonesian industry practice, or not treated with additional NaCl. Samples were incubated at 10, 15, 20 and 30 °C. In broth, μmax and Nmax were significantly affected by temperature and NaCl, respectively, with λ influenced by both parameters. In control fish, μmax was significantly affected by temperature and NaCl, except at 10 and 15 °C; for 6% NaCl treatment, growth was only observed at 20 and 30 °C. Under similar incubation conditions for broth and fish, histamine formation was markedly affected by NaCl concentration. In broth, -5.1 to -6.6 log μg of histamine was produced per CFU, versus -4.6 to -6.6 log μg per CFU in fish. This study demonstrated that mackerel treated with 6% NaCl and stored at 10-15 °C prevents growth of K. aerogenes strain TI24 and formation of toxic levels of histamine.
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Affiliation(s)
- Novalia Rachmawati
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia; Research and Development Centre for Marine and Fisheries Product Processing and Biotechnology, Ministry of Marine Affairs and Fisheries, Jakarta, Indonesia.
| | - Shane M Powell
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia
| | - Radestya Triwibowo
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia; Research and Development Centre for Marine and Fisheries Product Processing and Biotechnology, Ministry of Marine Affairs and Fisheries, Jakarta, Indonesia
| | - David S Nichols
- Central Science Laboratory, University of Tasmania, Hobart, Australia
| | - Tom Ross
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia
| | - Mark L Tamplin
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia
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21
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Khanh CV, Tomii E, Asada R, Sakamoto JJ, Furuta M, Tsuchido T. Detection Time Distribution of Microcolonies Formed by Individual Heat-Injured Cells of Escherichia coli. Biocontrol Sci 2022; 26:211-215. [PMID: 35013018 DOI: 10.4265/bio.26.211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
The microcolony formation at 30℃ on an enriched minimal salts agar plates by individual Escherichia coli cells heated at 50℃ was monitored with a time-lapse shadow image analysis system, MicroBio μ3DTM AutoScanner. While the time course of microcolony count detected every half an hour for the unheated cells seemingly demonstrated a normal distribution, that for the heated cell population demonstrated totally the growth delay probably resulting from cell injury and also interestingly distributed in its rather deformed pattern with a tailing. Those patterns of the cumulative counts of appearing microcolonies during the post-heating cultivation period were expressed in three different mathematical models. This approach may be proposed as a rapid cultivation method predictable for enumeration of viable and repairable injured cells in practical use.
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Affiliation(s)
- C Vo Khanh
- Department of Quantum and Radiation Engineering, Graduate School of Engineering, Osaka Prefecture University
| | - Enami Tomii
- Radiation Research Center, Osaka Prefecture University
| | - Ryoko Asada
- Department of Quantum and Radiation Engineering, Graduate School of Engineering, Osaka Prefecture University.,Radiation Research Center, Osaka Prefecture University.,Research Center of Microorganism Control, Organization for Research Promotion, Osaka Prefecture University
| | - Jin J Sakamoto
- Research Center of Microorganism Control, Organization for Research Promotion, Osaka Prefecture University.,MPES-3U and Faculty of Materials, Chemistry and Biotechnology, Kansai University
| | - Masakazu Furuta
- Department of Quantum and Radiation Engineering, Graduate School of Engineering, Osaka Prefecture University.,Radiation Research Center, Osaka Prefecture University.,Research Center of Microorganism Control, Organization for Research Promotion, Osaka Prefecture University
| | - Tetsuaki Tsuchido
- Research Center of Microorganism Control, Organization for Research Promotion, Osaka Prefecture University.,TriBioX Laboratories, Ltd
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22
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Dikyol C, Ercan UK. Evaluation of Penetration Depth of Antimicrobial Effect by Cold Atmospheric Plasma Treatment In vitro. PLASMA MEDICINE 2022. [DOI: 10.1615/plasmamed.2022043466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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23
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De Marchi S, García-Lojo D, Bodelón G, Pérez-Juste J, Pastoriza-Santos I. Plasmonic Au@Ag@mSiO 2 Nanorattles for In Situ Imaging of Bacterial Metabolism by Surface-Enhanced Raman Scattering Spectroscopy. ACS APPLIED MATERIALS & INTERFACES 2021; 13:61587-61597. [PMID: 34927427 PMCID: PMC8719315 DOI: 10.1021/acsami.1c21812] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
It is well known that microbial populations and their interactions are largely influenced by their secreted metabolites. Noninvasive and spatiotemporal monitoring and imaging of such extracellular metabolic byproducts can be correlated with biological phenotypes of interest and provide new insights into the structure and development of microbial communities. Herein, we report a surface-enhanced Raman scattering (SERS) hybrid substrate consisting of plasmonic Au@Ag@mSiO2 nanorattles for optophysiological monitoring of extracellular metabolism in microbial populations. A key element of the SERS substrate is the mesoporous silica shell encapsulating single plasmonic nanoparticles, which furnishes colloidal stability and molecular sieving capabilities to the engineered nanostructures, thereby realizing robust, sensitive, and reliable measurements. The reported SERS-based approach may be used as a powerful tool for deciphering the role of extracellular metabolites and physicochemical factors in microbial community dynamics and interactions.
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Affiliation(s)
- Sarah De Marchi
- CINBIO,
Universidade de Vigo, Departamento de Química Física, Campus Universitario As Lagoas, Marcosende, 36310 Vigo, Spain
- Galicia
Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36310 Vigo, Spain
| | - Daniel García-Lojo
- CINBIO,
Universidade de Vigo, Departamento de Química Física, Campus Universitario As Lagoas, Marcosende, 36310 Vigo, Spain
- Galicia
Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36310 Vigo, Spain
| | - Gustavo Bodelón
- CINBIO,
Universidade de Vigo, Departamento de Química Física, Campus Universitario As Lagoas, Marcosende, 36310 Vigo, Spain
- Galicia
Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36310 Vigo, Spain
| | - Jorge Pérez-Juste
- CINBIO,
Universidade de Vigo, Departamento de Química Física, Campus Universitario As Lagoas, Marcosende, 36310 Vigo, Spain
- Galicia
Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36310 Vigo, Spain
| | - Isabel Pastoriza-Santos
- CINBIO,
Universidade de Vigo, Departamento de Química Física, Campus Universitario As Lagoas, Marcosende, 36310 Vigo, Spain
- Galicia
Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36310 Vigo, Spain
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24
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Xu J, Xie Y, Paul NC, Roopesh MS, Shah DH, Tang J. Water sorption characteristics of freeze-dried bacteria in low-moisture foods. Int J Food Microbiol 2021; 362:109494. [PMID: 34895752 DOI: 10.1016/j.ijfoodmicro.2021.109494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 10/08/2021] [Accepted: 11/22/2021] [Indexed: 11/17/2022]
Abstract
Water sorption isotherms of bacteria reflect the water activity with the change of moisture content of bacteria at a specific temperature. The temperature-dependency of water activity change can help to understand the thermal resistance of bacteria during a thermal process. Thermal resistance of bacteria in low-moisture foods may differ significantly depending on the physiological characteristics of microorganisms, including cell structure, existence of biofilms, and growth state. Previous studies demonstrated that the incremental change of aw in bacterial cells during thermal treatments resulted in changes in their thermotolerance. In this study, a pathogen associated with low-moisture foods outbreaks, Salmonella Enteritidis PT30 (in planktonic and biofilm forms), and its validated surrogate, Enterococcus faecium, were lyophilized and their water sorption isotherms (WSI) at 20, 40, and 60 °C were determined by using a vapor sorption analyzer and simulated by the Guggenheim, Anderson and De Boer model (GAB). The published thermal death times at 80 °C (D80 °C-values) of these bacteria in low-moisture environments were related with their WSI-derived aw changes. The results showed that planktonic E. faecium and biofilms of Salmonella, exhibiting higher thermal resistance compared to the planktonic cultures of Salmonella, had a smaller increase in aw when thermally treated from 20 to 60 °C in sealed test cells. The computational modeling also showed that when temperature increased from 20 to 60 °C, with an increase in relative humidity from 10% to 60%, freeze-dried planktonic E. faecium and Salmonella cells would equilibrate to their surrounding environments in 0.15 s and 0.25 s, respectively, suggesting a rapid equilibration of bacterial cells to their microenvironment. However, control of bacteria with different cell structure and growth state would require further attentions on process design adjustment because of their different water sorption characteristics.
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Affiliation(s)
- Jie Xu
- Department of Biological Systems Engineering, Washington State University, P.O. Box 646120, Pullman, WA 99164-6120, USA; Center for Nanotechnology and Nanotoxicology, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA.
| | - Yucen Xie
- Department of Biological Systems Engineering, Washington State University, P.O. Box 646120, Pullman, WA 99164-6120, USA
| | - Narayan C Paul
- Texas A&M Veterinary Medical Diagnostic Laboratory, 483 Agronomy Rd, College Station, TCX 77843, USA
| | - M S Roopesh
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 3-16 Agriculture/Forestry Centre, Edmonton, AB T6G 2P5, Canada
| | - Devendra H Shah
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-6120, USA
| | - Juming Tang
- Department of Biological Systems Engineering, Washington State University, P.O. Box 646120, Pullman, WA 99164-6120, USA
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25
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Abstract
Biofilms are aggregates of bacterial cells surrounded by an extracellular matrix. Much progress has been made in studying biofilm growth on solid substrates; however, little is known about the biophysical mechanisms underlying biofilm development in three-dimensional confined environments in which the biofilm-dwelling cells must push against and even damage the surrounding environment to proliferate. Here, combining single-cell imaging, mutagenesis, and rheological measurement, we reveal the key morphogenesis steps of Vibrio cholerae biofilms embedded in hydrogels as they grow by four orders of magnitude from their initial size. We show that the morphodynamics and cell ordering in embedded biofilms are fundamentally different from those of biofilms on flat surfaces. Treating embedded biofilms as inclusions growing in an elastic medium, we quantitatively show that the stiffness contrast between the biofilm and its environment determines biofilm morphology and internal architecture, selecting between spherical biofilms with no cell ordering and oblate ellipsoidal biofilms with high cell ordering. When embedded in stiff gels, cells self-organize into a bipolar structure that resembles the molecular ordering in nematic liquid crystal droplets. In vitro biomechanical analysis shows that cell ordering arises from stress transmission across the biofilm-environment interface, mediated by specific matrix components. Our imaging technique and theoretical approach are generalizable to other biofilm-forming species and potentially to biofilms embedded in mucus or host tissues as during infection. Our results open an avenue to understand how confined cell communities grow by means of a compromise between their inherent developmental program and the mechanical constraints imposed by the environment.
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Polese P, Del Torre M, Stecchini ML. The COM-Poisson Process for Stochastic Modeling of Osmotic Inactivation Dynamics of Listeria monocytogenes. Front Microbiol 2021; 12:681468. [PMID: 34305844 PMCID: PMC8300431 DOI: 10.3389/fmicb.2021.681468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/31/2021] [Indexed: 11/13/2022] Open
Abstract
Controlling harmful microorganisms, such as Listeria monocytogenes, can require reliable inactivation steps, including those providing conditions (e.g., using high salt content) in which the pathogen could be progressively inactivated. Exposure to osmotic stress could result, however, in variation in the number of survivors, which needs to be carefully considered through appropriate dispersion measures for its impact on intervention practices. Variation in the experimental observations is due to uncertainty and biological variability in the microbial response. The Poisson distribution is suitable for modeling the variation of equi-dispersed count data when the naturally occurring randomness in bacterial numbers it is assumed. However, violation of equi-dispersion is quite often evident, leading to over-dispersion, i.e., non-randomness. This article proposes a statistical modeling approach for describing variation in osmotic inactivation of L. monocytogenes Scott A at different initial cell levels. The change of survivors over inactivation time was described as an exponential function in both the Poisson and in the Conway-Maxwell Poisson (COM-Poisson) processes, with the latter dealing with over-dispersion through a dispersion parameter. This parameter was modeled to describe the occurrence of non-randomness in the population distribution, even the one emerging with the osmotic treatment. The results revealed that the contribution of randomness to the total variance was dominant only on the lower-count survivors, while at higher counts the non-randomness contribution to the variance was shown to increase the total variance above the Poisson distribution. When the inactivation model was compared with random numbers generated in computer simulation, a good concordance between the experimental and the modeled data was obtained in the COM-Poisson process.
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Affiliation(s)
- Pierluigi Polese
- Polytechnic Department of Engineering and Architecture, University of Udine, Udine, Italy
| | - Manuela Del Torre
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
| | - Mara Lucia Stecchini
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Udine, Italy
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Falardeau J, Trmčić A, Wang S. The occurrence, growth, and biocontrol of Listeria monocytogenes in fresh and surface-ripened soft and semisoft cheeses. Compr Rev Food Sci Food Saf 2021; 20:4019-4048. [PMID: 34057273 DOI: 10.1111/1541-4337.12768] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/16/2021] [Accepted: 04/17/2021] [Indexed: 01/05/2023]
Abstract
Listeria monocytogenes continues to pose a food safety risk in ready-to-eat foods, including fresh and soft/semisoft cheeses. Despite L. monocytogenes being detected regularly along the cheese production continuum, variations in cheese style and intrinsic/extrinsic factors throughout the production process (e.g., pH, water activity, and temperature) affect the potential for L. monocytogenes survival and growth. As novel preservation strategies against the growth of L. monocytogenes in susceptible cheeses, researchers have investigated the use of various biocontrol strategies, including bacteriocins and bacteriocin-producing cultures, bacteriophages, and competition with native microbiota. Bacteriocins produced by lactic acid bacteria (LAB) are of particular interest to the dairy industry since they are often effective against Gram-positive organisms such as L. monocytogenes, and because many LAB are granted Generally Regarded as Safe (GRAS) status by global food safety authorities. Similarly, bacteriophages are also considered a safe form of biocontrol since they have high specificity for their target bacterium. Both bacteriocins and bacteriophages have shown success in reducing L. monocytogenes populations in cheeses in the short term, but regrowth of surviving cells can commonly occur in the finished cheeses. Competition with native microbiota, not mediated by bacteriocin production, has also shown potential to inhibit the growth of L. monocytogenes in cheeses, but the mechanisms are still unclear. Here, we have reviewed the current knowledge on the growth of L. monocytogenes in fresh and surface-ripened soft and semisoft cheeses, as well as the various methods used for biocontrol of this common foodborne pathogen.
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Affiliation(s)
- Justin Falardeau
- Department of Food, Nutrition, and Health, University of British Columbia, British Columbia, Vancouver, Canada
| | - Aljoša Trmčić
- Milk Quality Improvement Program, Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Siyun Wang
- Department of Food, Nutrition, and Health, University of British Columbia, British Columbia, Vancouver, Canada
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Makariti IP, Grivokostopoulos NC, Skandamis PN. Effect οf οxygen availability and pH οn adaptive acid tolerance response of immobilized Listeria monocytogenes in structured growth media. Food Microbiol 2021; 99:103826. [PMID: 34119111 DOI: 10.1016/j.fm.2021.103826] [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: 02/25/2021] [Revised: 05/01/2021] [Accepted: 05/03/2021] [Indexed: 10/21/2022]
Abstract
The aim of the present study was to evaluate the effect of oxygen availability (aerobic, hypoxic and anoxic conditions) and sub-optimal pH (6.2 and 5.5) in a structured medium (10% w/V gelatin) on the growth of two immobilized L. monocytogenes strains (C5, 6179) at 10 °C and their subsequent acid resistance (pH 2.0, e.g., gastric acidity). Anaerobic conditions resulted in lower bacterial population (P < 0.05) (7.8-8.2 log CFU/mL) at the end of storage than aerobic and hypoxic environment (8.5-9.0 log CFU/mL), a phenomenon that was intensified at lower pH (5.5), where no significant growth was observed for anaerobically grown cultures. Prolonged habituation of L. monocytogenes (15 days) at both pH increased its acid tolerance resulting in max. 10 times higher t4D (appx. 60 min). The combined effect though of oxygen availability and suboptimal pH on L. monocytogenes acid resistance was found to vary with the strain. Anoxically grown cultures at pH 5.5 exhibited the lowest tolerance towards lethal acid stress, with countable survivors occurring only until 20 min of exposure at pH 2.0. Elucidating the role of oxygen limiting conditions, often encountered in structured foods, on acid resistance of L. monocytogenes, would assist in assessing the capacity of L. monocytogenes originated from different food-related niches to withstand gastric acidity and possibly initiate infection.
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Affiliation(s)
- Ifigeneia P Makariti
- Laboratory of Food Quality Control and Hygiene, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece
| | - Nikos C Grivokostopoulos
- Laboratory of Food Quality Control and Hygiene, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece
| | - Panagiotis N Skandamis
- Laboratory of Food Quality Control and Hygiene, Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece.
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Denitrifying bacteria respond to and shape microscale gradients within particulate matrices. Commun Biol 2021; 4:570. [PMID: 33986448 PMCID: PMC8119678 DOI: 10.1038/s42003-021-02102-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 04/13/2021] [Indexed: 11/10/2022] Open
Abstract
Heterotrophic denitrification enables facultative anaerobes to continue growing even when limited by oxygen (O2) availability. Particles in particular provide physical matrices characterized by reduced O2 permeability even in well-oxygenated bulk conditions, creating microenvironments where microbial denitrifiers may proliferate. Whereas numerical particle models generally describe denitrification as a function of radius, here we provide evidence for heterogeneity of intraparticle denitrification activity due to local interactions within and among microcolonies. Pseudomonas aeruginosa cells and microcolonies act to metabolically shade each other, fostering anaerobic processes just microns from O2-saturated bulk water. Even within well-oxygenated fluid, suboxia and denitrification reproducibly developed and migrated along sharp 10 to 100 µm gradients, driven by the balance of oxidant diffusion and local respiration. Moreover, metabolic differentiation among densely packed cells is dictated by the diffusional supply of O2, leading to distinct bimodality in the distribution of nitrate and nitrite reductase expression. The initial seeding density controls the speed at which anoxia develops, and even particles seeded with few bacteria remain capable of becoming anoxic. Our empirical results capture the dynamics of denitrifier gene expression in direct association with O2 concentrations over microscale physical matrices, providing observations of the co-occurrence and spatial arrangement of aerobic and anaerobic processes. Smriga et al. investigate heterotrophic denitrification in particulate matrices. Their model shows that Pseudomonas aeruginosa cells and microcolonies metabolically shade each other, allowing denitrification to occur microns away from O2-saturated bulk water, and simulates microscale effects of a bulk system.
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Xue H, Kurokawa M, Ying BW. Correlation between the spatial distribution and colony size was common for monogenetic bacteria in laboratory conditions. BMC Microbiol 2021; 21:114. [PMID: 33858359 PMCID: PMC8051089 DOI: 10.1186/s12866-021-02180-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/22/2021] [Indexed: 12/02/2022] Open
Abstract
Background Geographically separated population growth of microbes is a common phenomenon in microbial ecology. Colonies are representative of the morphological characteristics of this structured population growth. Pattern formation by single colonies has been intensively studied, whereas the spatial distribution of colonies is poorly investigated. Results The present study describes a first trial to address the questions of whether and how the spatial distribution of colonies determines the final colony size using the model microorganism Escherichia coli, colonies of which can be grown under well-controlled laboratory conditions. A computational tool for image processing was developed to evaluate colony density, colony size and size variation, and the Voronoi diagram was applied for spatial analysis of colonies with identical space resources. A positive correlation between the final colony size and the Voronoi area was commonly identified, independent of genomic and nutritional differences, which disturbed the colony size and size variation. Conclusions This novel finding of a universal correlation between the spatial distribution and colony size not only indicated the fair distribution of spatial resources for monogenetic colonies growing with identical space resources but also indicated that the initial localization of the microbial colonies decided by chance determined the fate of the subsequent population growth. This study provides a valuable example for quantitative analysis of the complex microbial ecosystems by means of experimental ecology. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02180-8.
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Affiliation(s)
- Heng Xue
- School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Masaomi Kurokawa
- School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Bei-Wen Ying
- School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan.
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31
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Settier-Ramírez L, López-Carballo G, Gavara R, Hernández-Muñoz P. Evaluation of Lactococcus lactis subsp. lactis as protective culture for active packaging of non-fermented foods: Creamy mushroom soup and sliced cooked ham. Food Control 2021. [DOI: 10.1016/j.foodcont.2020.107802] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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32
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Levante A, Bertani G, Bottari B, Bernini V, Lazzi C, Gatti M, Neviani E. How new molecular approaches have contributed to shedding light on microbial dynamics in Parmigiano Reggiano cheese. Curr Opin Food Sci 2021. [DOI: 10.1016/j.cofs.2020.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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33
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El Kadri H, Costello KM, Thomas P, Wantock T, Sandison G, Harle T, Fabris AL, Gutierrez-Merino J, Velliou EG. The antimicrobial efficacy of remote cold atmospheric plasma effluent against single and mixed bacterial biofilms of varying age. Food Res Int 2021; 141:110126. [PMID: 33641993 DOI: 10.1016/j.foodres.2021.110126] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 01/07/2021] [Accepted: 01/07/2021] [Indexed: 12/24/2022]
Abstract
Cold atmospheric plasma (CAP) is a minimal food processing technology of increasing interest in the food industry, as it is mild in nature compared to traditional methods (e.g. pasteurisation) and thus can maintain the food's desirable qualities. However, due to this mild nature, the potential exists for post-treatment microbial survival and/or stress adaptation. Furthermore, biofilm inactivation by CAP is underexplored and mostly studied on specific foods or on plastic/polymer surfaces. Co-culture effects, biofilm age, and innate biofilm-associated resistance could all impact CAP efficacy, while studies on real foods are limited to the food product investigated without accounting for structural complexity. The effect of a Remote and Enclosed CAP device (Fourth State Medicine Ltd) was investigated on Escherichia coli and Listeria innocua grown as planktonic cells and as single or mixed bacterial biofilms of variable age, on a biphasic viscoelastic food model of controlled rheological and structural complexity. Post-CAP viability was assessed by plate counts, cell sublethal injury was quantified using flow cytometry, and biofilms were characterised and assessed using total protein content and microscopy techniques. A greater impact of CAP on planktonic cells was observed at higher air flow rates, where the ReCAP device operates in a mode more favourable to reactive oxygen species than reactive nitrogen species. Although planktonic E. coli was more susceptible to CAP than planktonic L. innocua, the opposite was observed in biofilm form. The efficacy of CAP was reduced with increasing biofilm age. Furthermore, E. coli produced much higher protein content in both single and mixed biofilms than L. innocua. Consequently, greater survival of L. innocua in mixed biofilms was attributed to a protective effect from E. coli. These results show that biofilm susceptibility to CAP is age and bacteria dependent, and that in mixed biofilms bacteria may become less susceptible to CAP. These findings are of significance to the food industry for the development of effective food decontamination methods using CAP.
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Affiliation(s)
- Hani El Kadri
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK
| | - Katherine M Costello
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK
| | - Phillip Thomas
- Surrey Space Centre, University of Surrey, Guildford GU2 7XH, UK
| | - Thomas Wantock
- Fourth State Medicine Ltd, Longfield, Fernhurst, Haslemere GU27 3HA, UK
| | - Gavin Sandison
- Fourth State Medicine Ltd, Longfield, Fernhurst, Haslemere GU27 3HA, UK
| | - Thomas Harle
- Fourth State Medicine Ltd, Longfield, Fernhurst, Haslemere GU27 3HA, UK
| | | | | | - Eirini G Velliou
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering, University of Surrey, Guildford GU2 7XH, UK.
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34
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Tian F, Lee SY, Woo SY, Choi HY, Heo S, Nah G, Chun HS. Transcriptomic responses of Aspergillus flavus to temperature and oxidative stresses during aflatoxin production. Sci Rep 2021; 11:2803. [PMID: 33531617 PMCID: PMC7854668 DOI: 10.1038/s41598-021-82488-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/18/2021] [Indexed: 01/30/2023] Open
Abstract
Aflatoxin is a group of polyketide-derived carcinogenic and mutagenic secondary metabolites produced by Aspergillus flavus that negatively impact global food security and threaten the health of both humans and livestock. Aflatoxin biosynthesis is strongly affected by the fungal developmental stage, cultivation conditions, and environmental stress. In this study, a novel float culture method was used to examine the direct responses of the A. flavus transcriptome to temperature stress, oxidative stress, and their dual effects during the aflatoxin production stage. The transcriptomic response of A. flavus illustrated that the co-regulation of different secondary metabolic pathways likely contributes to maintaining cellular homeostasis and promoting cell survival under stress conditions. In particular, aflatoxin biosynthetic gene expression was downregulated, while genes encoding secondary metabolites with antioxidant properties, such as kojic acid and imizoquins, were upregulated under stress conditions. Multiple mitochondrial function-related genes, including those encoding NADH:ubiquinone oxidoreductase, ubiquinol-cytochrome C reductase, and alternative oxidase, were differentially expressed. These data can provide insights into the important mechanisms through which secondary metabolism in A. flavus is co-regulated and facilitate the deployment of various approaches for the effective control and prevention of aflatoxin contamination in food crops.
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Affiliation(s)
- Fei Tian
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - Sang Yoo Lee
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - So Young Woo
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - Hwa Young Choi
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - Seongeun Heo
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - Gyoungju Nah
- grid.31501.360000 0004 0470 5905Genome Analysis Center at National Instrumentation Center for Environmental Management, Seoul National University, Seoul, Korea
| | - Hyang Sook Chun
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
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35
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Hagberg A, Rzhepishevska O, Semenets A, Cisneros DA, Ramstedt M. Surface analysis of bacterial systems using cryo‐X‐ray photoelectron spectroscopy. SURF INTERFACE ANAL 2020. [DOI: 10.1002/sia.6854] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
| | | | - Anastasiia Semenets
- Department of Chemistry, UCMR Umeå University Umeå Sweden
- Department of Microbiology Virology and Biotechnology, Odessa National I.I.Mechnikov University Odessa Ukraine
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36
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Pérez‐Arauz Á, Rodríguez‐Hernández A, Rocío López‐Cuellar M, Martínez‐Juárez V, Chavarría‐Hernández N. Films based on Pectin, Gellan, EDTA, and bacteriocin‐like compounds produced by
Streptococcus infantarius
for the bacterial control in fish packaging. J FOOD PROCESS PRES 2020. [DOI: 10.1111/jfpp.15006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Ángel‐Omar Pérez‐Arauz
- Cuerpo Académico de Biotecnología Agroalimentaria, Instituto de Ciencias Agropecuarias Universidad Autónoma del Estado de Hidalgo Tulancingo de Bravo México
| | - Adriana‐Inés Rodríguez‐Hernández
- Cuerpo Académico de Biotecnología Agroalimentaria, Instituto de Ciencias Agropecuarias Universidad Autónoma del Estado de Hidalgo Tulancingo de Bravo México
| | - Ma. Rocío López‐Cuellar
- Cuerpo Académico de Biotecnología Agroalimentaria, Instituto de Ciencias Agropecuarias Universidad Autónoma del Estado de Hidalgo Tulancingo de Bravo México
| | - Víctor‐Manuel Martínez‐Juárez
- Área Académica de Medicina Veterinaria y Zootecnia, Instituto de Ciencias Agropecuarias, Universidad Autónoma del Estado de Hidalgo Tulancingo de Bravo México
| | - Norberto Chavarría‐Hernández
- Cuerpo Académico de Biotecnología Agroalimentaria, Instituto de Ciencias Agropecuarias Universidad Autónoma del Estado de Hidalgo Tulancingo de Bravo México
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Eriksen RS, Mitarai N, Sneppen K. On Phage Adsorption to Bacterial Chains. Biophys J 2020; 119:1896-1904. [PMID: 33069271 PMCID: PMC7677248 DOI: 10.1016/j.bpj.2020.09.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 09/16/2020] [Accepted: 09/21/2020] [Indexed: 11/15/2022] Open
Abstract
Bacteria often arrange themselves in various spatial configurations, which changes how they interact with their surroundings. In this work, we investigate how the structure of the bacterial arrangements influences the adsorption of bacteriophages. We quantify how the adsorption rate scales with the number of bacteria in the arrangement and show that the adsorption rates for microcolonies (increasing with exponent ∼1/3) and bacterial chains (increasing with exponent ∼0.5-0.8) are substantially lower than for well-mixed bacteria (increasing with exponent 1). We further show that, after infection, the spatially clustered arrangements reduce the effective burst size by more than 50% and cause substantial superinfections in a very short time interval after phage lysis.
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Affiliation(s)
| | - Namiko Mitarai
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Kim Sneppen
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
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38
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Rooney LM, Amos WB, Hoskisson PA, McConnell G. Intra-colony channels in E. coli function as a nutrient uptake system. THE ISME JOURNAL 2020; 14:2461-2473. [PMID: 32555430 PMCID: PMC7490401 DOI: 10.1038/s41396-020-0700-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 05/05/2020] [Accepted: 05/12/2020] [Indexed: 12/13/2022]
Abstract
The ability of microorganisms to grow as aggregated assemblages has been known for many years, however their structure has remained largely unexplored across multiple spatial scales. The development of the Mesolens, an optical system which uniquely allows simultaneous imaging of individual bacteria over a 36 mm2 field of view, has enabled the study of mature Escherichia coli macro-colony biofilm architecture like never before. The Mesolens enabled the discovery of intra-colony channels on the order of 10 μm in diameter, that are integral to E. coli macro-colony biofilms and form as an emergent property of biofilm growth. These channels have a characteristic structure and re-form after total mechanical disaggregation of the colony. We demonstrate that the channels are able to transport particles and play a role in the acquisition of and distribution of nutrients through the biofilm. These channels potentially offer a new route for the delivery of dispersal agents for antimicrobial drugs to biofilms, ultimately lowering their impact on public health and industry.
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Affiliation(s)
- Liam M Rooney
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK.
- Institute of Biological Chemistry, Biophysics and Bioengineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| | - William B Amos
- Department of Physics, SUPA, University of Strathclyde, 107 Rottenrow East, Glasgow, G4 0NG, UK
| | - Paul A Hoskisson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, UK
| | - Gail McConnell
- Department of Physics, SUPA, University of Strathclyde, 107 Rottenrow East, Glasgow, G4 0NG, UK
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39
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Bär J, Boumasmoud M, Kouyos RD, Zinkernagel AS, Vulin C. Efficient microbial colony growth dynamics quantification with ColTapp, an automated image analysis application. Sci Rep 2020; 10:16084. [PMID: 32999342 PMCID: PMC7528005 DOI: 10.1038/s41598-020-72979-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/08/2020] [Indexed: 12/14/2022] Open
Abstract
Populations of genetically identical bacteria are phenotypically heterogeneous, giving rise to population functionalities that would not be possible in homogeneous populations. For instance, a proportion of non-dividing bacteria could persist through antibiotic challenges and secure population survival. This heterogeneity can be studied in complex environmental or clinical samples by spreading the bacteria on agar plates and monitoring time to growth resumption in order to infer their metabolic state distribution. We present ColTapp, the Colony Time-lapse application for bacterial colony growth quantification. Its intuitive graphical user interface allows users to analyze time-lapse images of agar plates to monitor size, color and morphology of colonies. Additionally, images at isolated timepoints can be used to estimate lag time. Using ColTapp, we analyze a dataset of Staphylococcus aureus time-lapse images including populations with heterogeneous lag time. Colonies on dense plates reach saturation early, leading to overestimation of lag time from isolated images. We show that this bias can be corrected by taking into account the area available to each colony on the plate. We envision that in clinical settings, improved analysis of colony growth dynamics may help treatment decisions oriented towards personalized antibiotic therapies.
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Affiliation(s)
- Julian Bär
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Mathilde Boumasmoud
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Roger D Kouyos
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Institute of Medical Virology, University of Zurich, Zurich, Switzerland
| | - Annelies S Zinkernagel
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Clément Vulin
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland. .,Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092, Zurich, Switzerland. .,Department of Environmental Microbiology, 8600, Eawag, Dubendorf, Switzerland.
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40
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Confocal Laser Microscopy Analysis of Listeria monocytogenes Biofilms and Spatially Organized Communities. Methods Mol Biol 2020. [PMID: 32975771 DOI: 10.1007/978-1-0716-0982-8_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The behavior of Listeria monocytogenes communities in the food chain is closely associated with their spatial organization. Whether as biofilms on industrial surfaces or as microcolonies in food matrices, the resulting physiological diversification combined with the presence of extracellular polymeric substances (EPS) triggers emergent community functions involved in the pathogen survival and persistence (e.g., tolerance to dehydration, biocides, or preservatives). In this contribution, we present a noninvasive confocal laser microscopy (CLM) protocol allowing exploration of the spatial organization of L. monocytogenes communities on various inert or nutritive materials relevant for the food industry.
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Tian F, Lee SY, Woo SY, Choi HY, Chun HS. A float culture method for fungal secondary metabolism study using hydrophilic polyvinylidene fluoride membranes. Anal Biochem 2020; 599:113722. [PMID: 32275893 DOI: 10.1016/j.ab.2020.113722] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 03/21/2020] [Accepted: 04/03/2020] [Indexed: 01/04/2023]
Abstract
Fungal metabolism is affected by both the developmental stage and cultivation conditions. Fungal growth in solid culture reflects natural conditions more closely than growth in liquid culture; however, because the mycelium cannot be harvested easily and the medium composition cannot be modified during incubation, the approach has some limitations when compared to liquid culture methods. The float culture incubation method introduced herein enables fungus to develop similar colonies to those on solid culture. This is a simple method that leads to the production of high-quality RNA samples.
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Affiliation(s)
- Fei Tian
- Advanced Food Safety Research Group, BK21 Plus, School of Food Science and Technology, Chung-Ang University, Anseong, 17546, South Korea
| | - Sang Yoo Lee
- Advanced Food Safety Research Group, BK21 Plus, School of Food Science and Technology, Chung-Ang University, Anseong, 17546, South Korea
| | - So Young Woo
- Advanced Food Safety Research Group, BK21 Plus, School of Food Science and Technology, Chung-Ang University, Anseong, 17546, South Korea
| | - Hwa Young Choi
- Advanced Food Safety Research Group, BK21 Plus, School of Food Science and Technology, Chung-Ang University, Anseong, 17546, South Korea
| | - Hyang Sook Chun
- Advanced Food Safety Research Group, BK21 Plus, School of Food Science and Technology, Chung-Ang University, Anseong, 17546, South Korea.
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Eriksen RS, Mitarai N, Sneppen K. Sustainability of spatially distributed bacteria-phage systems. Sci Rep 2020; 10:3154. [PMID: 32081858 PMCID: PMC7035299 DOI: 10.1038/s41598-020-59635-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 01/09/2020] [Indexed: 11/09/2022] Open
Abstract
Virulent phages can expose their bacterial hosts to devastating epidemics, in principle leading to complete elimination of their hosts. Although experiments indeed confirm a large reduction of susceptible bacteria, there are no reports of complete extinctions. We here address this phenomenon from the perspective of spatial organization of bacteria and how this can influence the final survival of them. By modelling the transient dynamics of bacteria and phages when they are introduced into an environment with finite resources, we quantify how time delayed lysis, the spatial separation of initial bacterial positions, and the self-protection of bacteria growing in spherical colonies favour bacterial survival. Our results suggest that spatial structures on the millimetre and submillimetre scale play an important role in maintaining microbial diversity.
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Affiliation(s)
| | - Namiko Mitarai
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
| | - Kim Sneppen
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
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El Kadri H, Alaizoki A, Celen T, Smith M, Onyeaka H. The effect of low-temperature long-time (LTLT) cooking on survival of potentially pathogenic Clostridium perfringens in beef. Int J Food Microbiol 2020; 320:108540. [PMID: 32044624 DOI: 10.1016/j.ijfoodmicro.2020.108540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 10/10/2019] [Accepted: 01/26/2020] [Indexed: 02/02/2023]
Abstract
Low-temperature long-time (LTLT) cooking may lead to risk of potential survival of pathogenic bacteria such as Clostridium perfringens in cooked meat. In this study, the effect of LTLT cooking on C. perfringens was investigated at temperatures commonly used by caterers. Brain heart infusion broth (BHIB) and meat cubes in pouches (vacuumed or non-vacuumed) were inoculated with C. perfringens (NCTC 8238) and heated at temperatures of 48 °C, 53 °C, 55 °C, 60 °C and 70 °C. The viability of C. perfringens in BHIB and meat was monitored using plate counting and the D-value of each thermal treatment was determined. The recovery of C. perfringens after thermal treatment was assessed using optical density measurements. Flow cytometry analysis was used to assess the physiological status (death/injury) of C. perfringens cells in BHIB. The results showed that the required log reduction (6-log) of C. perfringens can be achieved at 55 °C but not at 48 °C or 53 °C. The D-values at all temperatures were higher in meat compared to BHIB while the D-value at 55 °C was higher in non-vacuum compared to vacuum sealed meat. C. perfringens cells were able to recover and grow to pathogenic levels when thermal treatment was unable to achieve the required 6-log reduction. In BHIB, percentage of dead cells increased gradually at 48 °C, 53 °C and 55 °C while an immediate increase (>95%) was observed at 60 °C and 70 °C. These results are important to food safety authorities allowing to set the time-temperature combinations to be used in LTLT cooking to obtain safe meat.
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Affiliation(s)
- Hani El Kadri
- School of Chemical Engineering, University of Birmingham, B15 2TT Birmingham, United Kingdom
| | - Alaa Alaizoki
- School of Chemical Engineering, University of Birmingham, B15 2TT Birmingham, United Kingdom
| | - Teyfik Celen
- School of Chemical Engineering, University of Birmingham, B15 2TT Birmingham, United Kingdom
| | - Madeleine Smith
- School of Chemical Engineering, University of Birmingham, B15 2TT Birmingham, United Kingdom
| | - Helen Onyeaka
- School of Chemical Engineering, University of Birmingham, B15 2TT Birmingham, United Kingdom.
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Verheyen D, Baka M, Akkermans S, Skåra T, Van Impe JF. Effect of microstructure and initial cell conditions on thermal inactivation kinetics and sublethal injury of Listeria monocytogenes in fish-based food model systems. Food Microbiol 2019; 84:103267. [DOI: 10.1016/j.fm.2019.103267] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 05/22/2019] [Accepted: 07/10/2019] [Indexed: 01/07/2023]
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Costello KM, Gutierrez‐Merino J, Bussemaker M, Smet C, Van Impe JF, Velliou EG. A multi‐scale analysis of the effect of complex viscoelastic models on
Listeria
dynamics and adaptation in co‐culture systems. AIChE J 2019. [DOI: 10.1002/aic.16761] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Katherine M. Costello
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering University of Surrey Guildford UK
| | | | - Madeleine Bussemaker
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering University of Surrey Guildford UK
| | - Cindy Smet
- Chemical and Biochemical Process Technology and Control Laboratory (BioTeC+) KU Leuven, Sustainable Chemical Process Technology Ghent Belgium
| | - Jan F. Van Impe
- Chemical and Biochemical Process Technology and Control Laboratory (BioTeC+) KU Leuven, Sustainable Chemical Process Technology Ghent Belgium
| | - Eirini G. Velliou
- Bioprocess and Biochemical Engineering Group (BioProChem), Department of Chemical and Process Engineering University of Surrey Guildford UK
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Kumaunang M, Sanchart C, Suyotha W, Maneerat S. Virgibacillus halodenitrificans MSK-10P, a Potential Protease-producing Starter Culture for Fermented Shrimp Paste (kapi) Production. JOURNAL OF AQUATIC FOOD PRODUCT TECHNOLOGY 2019. [DOI: 10.1080/10498850.2019.1652874] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Maureen Kumaunang
- Biotechnology for Bioresource Utilization Laboratory, Department of Industrial Biotechnology, Faculty of Agro‑Industry, Prince of Songkla University, HatYai, Thailand
- Department of Chemistry, Faculty of Mathematics and Natural Science, Sam Ratulangi University, Manado, Indonesia
| | - Chatthaphisuth Sanchart
- Biotechnology for Bioresource Utilization Laboratory, Department of Industrial Biotechnology, Faculty of Agro‑Industry, Prince of Songkla University, HatYai, Thailand
| | - Wasana Suyotha
- Biotechnology for Bioresource Utilization Laboratory, Department of Industrial Biotechnology, Faculty of Agro‑Industry, Prince of Songkla University, HatYai, Thailand
| | - Suppasil Maneerat
- Biotechnology for Bioresource Utilization Laboratory, Department of Industrial Biotechnology, Faculty of Agro‑Industry, Prince of Songkla University, HatYai, Thailand
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Verheyen D, Xu XM, Govaert M, Baka M, Skåra T, Van Impe JF. Food Microstructure and Fat Content Affect Growth Morphology, Growth Kinetics, and Preferred Phase for Cell Growth of Listeria monocytogenes in Fish-Based Model Systems. Appl Environ Microbiol 2019; 85:e00707-19. [PMID: 31175191 PMCID: PMC6677851 DOI: 10.1128/aem.00707-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/30/2019] [Indexed: 11/20/2022] Open
Abstract
Food microstructure significantly affects microbial growth dynamics, but knowledge concerning the exact influencing mechanisms at a microscopic scale is limited. The food microstructural influence on Listeria monocytogenes (green fluorescent protein strain) growth at 10°C in fish-based food model systems was investigated by confocal laser scanning microscopy. The model systems had different microstructures, i.e., liquid, xanthan (high-viscosity liquid), aqueous gel, and emulsion and gelled emulsion systems varying in fat content. Bacteria grew as single cells, small aggregates, and microcolonies of different sizes (based on colony radii [size I, 1.5 to 5.0 μm; size II, 5.0 to 10.0 μm; size III, 10.0 to 15.0 μm; and size IV, ≥15 μm]). In the liquid, small aggregates and size I microcolonies were predominantly present, while size II and III microcolonies were predominant in the xanthan and aqueous gel. Cells in the emulsions and gelled emulsions grew in the aqueous phase and on the fat-water interface. A microbial adhesion to solvent assay demonstrated limited bacterial nonpolar solvent affinities, implying that this behavior was probably not caused by cell surface hydrophobicity. In systems containing 1 and 5% fat, the largest cell volume was mainly represented by size I and II microcolonies, while at 10 and 20% fat a few size IV microcolonies comprised nearly the total cell volume. Microscopic results (concerning, e.g., growth morphology, microcolony size, intercolony distances, and the preferred phase for growth) were related to previously obtained macroscopic growth dynamics in the model systems for an L. monocytogenes strain cocktail, leading to more substantiated explanations for the influence of food microstructural aspects on lag phase duration and growth rate.IMPORTANCEListeria monocytogenes is one of the most hazardous foodborne pathogens due to the high fatality rate of the disease (i.e., listeriosis). In this study, the growth behavior of L. monocytogenes was investigated at a microscopic scale in food model systems that mimic processed fish products (e.g., fish paté and fish soup), and the results were related to macroscopic growth parameters. Many studies have previously focused on the food microstructural influence on microbial growth. The novelty of this work lies in (i) the microscopic investigation of products with a complex composition and/or structure using confocal laser scanning microscopy and (ii) the direct link to the macroscopic level. Growth behavior (i.e., concerning bacterial growth morphology and preferred phase for growth) was more complex than assumed in common macroscopic studies. Consequently, the effectiveness of industrial antimicrobial food preservation technologies (e.g., thermal processing) might be overestimated for certain products, which may have critical food safety implications.
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Affiliation(s)
- Davy Verheyen
- BioTeC+, Chemical and Biochemical Process Technology and Control, KU Leuven, Ghent, Belgium
- OPTEC, Optimization in Engineering Center of Excellence, KU Leuven, Ghent, Belgium
- CPMF, Flemish Cluster Predictive Microbiology in Foods, KU Leuven, Ghent, Belgium
| | - Xiang Ming Xu
- Centre for Organelle Research, University of Stavanger, Stavanger, Norway
| | - Marlies Govaert
- BioTeC+, Chemical and Biochemical Process Technology and Control, KU Leuven, Ghent, Belgium
- OPTEC, Optimization in Engineering Center of Excellence, KU Leuven, Ghent, Belgium
- CPMF, Flemish Cluster Predictive Microbiology in Foods, KU Leuven, Ghent, Belgium
| | - Maria Baka
- BioTeC+, Chemical and Biochemical Process Technology and Control, KU Leuven, Ghent, Belgium
- OPTEC, Optimization in Engineering Center of Excellence, KU Leuven, Ghent, Belgium
- CPMF, Flemish Cluster Predictive Microbiology in Foods, KU Leuven, Ghent, Belgium
| | | | - Jan F Van Impe
- BioTeC+, Chemical and Biochemical Process Technology and Control, KU Leuven, Ghent, Belgium
- OPTEC, Optimization in Engineering Center of Excellence, KU Leuven, Ghent, Belgium
- CPMF, Flemish Cluster Predictive Microbiology in Foods, KU Leuven, Ghent, Belgium
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Tarazanova M, Huppertz T, Starrenburg M, Todt T, van Hijum S, Kok J, Bachmann H. Transcriptional response of Lactococcus lactis during bacterial emulsification. PLoS One 2019; 14:e0220048. [PMID: 31344087 PMCID: PMC6657864 DOI: 10.1371/journal.pone.0220048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/08/2019] [Indexed: 12/25/2022] Open
Abstract
Microbial surface properties are important for interactions with the environment in which cells reside. Surface properties of lactic acid bacteria significantly vary and some strains can form strong emulsions when mixed with a hydrocarbon. Lactococcus lactis NCDO712 forms oil-in-water emulsions upon mixing of a cell suspension with petroleum. In the emulsion the bacteria locate at the oil-water interphase which is consistent with Pickering stabilization. Cells of strain NCDO712 mixed with sunflower seed oil did not stabilize the oil droplets. This study shows that the addition of either ethanol or ammonium sulfate led to cell aggregation, which subsequently allowed stabilizing oil-in-water emulsions. From this, we conclude that bacterial cell aggregation is important for emulsion droplet stabilization. To determine how bacterial emulsification influences the microbial transcriptome RNAseq analysis was performed on lactococci taken from the oil-water interphase. In comparison to cells in suspension 72 genes were significantly differentially expressed with a more than 4-fold difference. The majority of these genes encode proteins involved in transport processes and the metabolism of amino acids, carbohydrates and ions. Especially the proportion of genes belonging to the CodY regulon was high. Our results also point out that in a complex environment such as food fermentations a heterogeneous response of microbes might be caused by microbe-matrix interactions. In addition, microdroplet technologies are increasingly used in research. The understanding of interactions between bacterial cells and oil-water interphases is of importance for conducting and interpreting such experiments.
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Affiliation(s)
- Mariya Tarazanova
- TI Food and Nutrition, AN Wageningen, The Netherlands
- NIZO, Ede BA, The Netherlands
- Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - Thom Huppertz
- TI Food and Nutrition, AN Wageningen, The Netherlands
- NIZO, Ede BA, The Netherlands
| | - Marjo Starrenburg
- TI Food and Nutrition, AN Wageningen, The Netherlands
- NIZO, Ede BA, The Netherlands
- Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - Tilman Todt
- Radboud University Medical Centre CMBI, Geert Grooteplein Nijmegen, The Netherlands
- HAN, University of Applied Sciences, PGL Nijmegen, The Netherlands
| | - Sacha van Hijum
- TI Food and Nutrition, AN Wageningen, The Netherlands
- NIZO, Ede BA, The Netherlands
- Radboud University Medical Centre CMBI, Geert Grooteplein Nijmegen, The Netherlands
| | - Jan Kok
- TI Food and Nutrition, AN Wageningen, The Netherlands
- Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - Herwig Bachmann
- TI Food and Nutrition, AN Wageningen, The Netherlands
- NIZO, Ede BA, The Netherlands
- * E-mail:
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49
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Wilson L, Iqbal KM, Simmons-Ehrhardt T, Bertino MF, Shah MR, Yadavalli VK, Ehrhardt CJ. Customizable 3D printed diffusion chambers for studies of bacterial pathogen phenotypes in complex environments. J Microbiol Methods 2019; 162:8-15. [PMID: 31085208 DOI: 10.1016/j.mimet.2019.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/03/2019] [Accepted: 05/03/2019] [Indexed: 11/17/2022]
Abstract
Gaps in our understanding of the natural ecology and survival mechanisms of pathogenic bacteria in complex microenvironments such as soil typically occur due to the difficulty in characterizing biochemical profiles and morphological characteristics as they exist in environmental samples. Conversely, accurate simulation of the abiotic and biotic chemistries of soil habitats within the laboratory is often a significant challenge. Herein, we present the fabrication of customizable and precisely engineered 3D printed diffusion chambers that can be used to incubate bacterial cultures directly in soil matrices within a controlled laboratory experiment, and study the dynamics between bacterial cells and soil components. As part of the design process, different types of 3D printing materials were evaluated for ease of sterilization, structural integrity throughout the experiment, as well as cost/ease of production. To demonstrate potential applications for environmental studies, the diffusion chamber was used to incubate cultures of Bacillus cereus T-strain and Escherichia coli strain O157 directly in soil matrices. We show that the chamber facilitates diffusion of abiotic/biotic components of the soil with target cells without contamination from in situ microbial communities, while allowing for single cell and ensemble level phenotypic analyses of bacteria cultured with and without soil matrices.
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Affiliation(s)
- Lyddia Wilson
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA 23284, United States of America
| | | | - Terrie Simmons-Ehrhardt
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA 23284, United States of America
| | - Massimo F Bertino
- Department of Physics, Virginia Commonwealth University, Richmond, VA 23284, United States of America
| | | | - Vamsi K Yadavalli
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA 23284, United States of America
| | - Christopher J Ehrhardt
- Department of Forensic Science, Virginia Commonwealth University, Richmond, VA 23284, United States of America.
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50
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Qi L, Christopher GF. Role of Flagella, Type IV Pili, Biosurfactants, and Extracellular Polymeric Substance Polysaccharides on the Formation of Pellicles by Pseudomonas aeruginosa. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:5294-5304. [PMID: 30883129 DOI: 10.1021/acs.langmuir.9b00271] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Microbial biofilms are viscoelastic materials formed by bacteria, which occur on solid surfaces, at liquid interfaces, or in free solution. Although solid surface biofilms have been widely studied, pellicles, biofilms at liquid interfaces, have had significantly less focus. In this work, interfacial shear rheology and scanning electron microscopy imaging are used to characterize how flagella, type IV pili, biosurfactants, and extracellular polymeric substance polysaccharides affect the formation of pellicles by Pseudomonas aeruginosa at an air/water interface. Pellicles still form with the loss of a single biological attachment mechanism, which is hypothesized to be due to surface tension-aided attachment. Changes in the surface structure of the pellicles are observed when changing both the function/structure of type IV pili, removing the flagella, or stopping the expression of biosurfactants. However, these changes do not appear to affect pellicle elasticity in a consistent way. Traits that affect adsorption and growth/spreading appear to affect pellicles in a manner consistent with literature results for solid surface biofilms; small differences are seen in attachment-related mechanisms, which may occur due to surface tension.
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Affiliation(s)
- Lingjuan Qi
- Department of Mechanical Engineering , Texas Tech University , Lubbock 79409 , United States
| | - Gordon F Christopher
- Department of Mechanical Engineering , Texas Tech University , Lubbock 79409 , United States
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