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Wang T, Li X, Liu H, Liu H, Xia Y, Xun L. Microorganisms uptake zero-valent sulfur via membrane lipid dissolution of octasulfur and intracellular solubilization as persulfide. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 922:170504. [PMID: 38307292 DOI: 10.1016/j.scitotenv.2024.170504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/19/2024] [Accepted: 01/25/2024] [Indexed: 02/04/2024]
Abstract
Zero-valent sulfur, commonly utilized as a fertilizer or fungicide, is prevalent in various environmental contexts. Its most stable and predominant form, octasulfur (S8), plays a crucial role in microbial sulfur metabolism, either through oxidation or reduction. However, the mechanism underlying its cellular uptake remains elusive. We presented evidence that zero-valent sulfur was adsorbed to the cell surface and then dissolved into the membrane lipid layer as lipid-soluble S8 molecules, which reacted with cellular low-molecular thiols to form persulfide, e.g., glutathione persulfide (GSSH), in the cytoplasm. The process brought extracellular zero-valent sulfur into the cells. When persulfide dioxygenase is present in the cells, GSSH will be oxidized. Otherwise, GSSH will react with another glutathione (GSH) to produce glutathione disulfide (GSSG) and hydrogen sulfide (H2S). The mechanism is different from simple diffusion, as insoluble S8 becomes soluble GSSH after crossing the cytoplasmic membrane. The uptake process is limited by physical contact of insoluble zero-valent sulfur with microbial cells and the regeneration of cellular thiols. Our findings elucidate the cellular uptake mechanism of zero-valent sulfur, which provides critical information for its application in agricultural practices and the bioremediation of sulfur contaminants and heavy metals.
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Affiliation(s)
- Tianqi Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Xiaoju Li
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Honglei Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Huaiwei Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yongzhen Xia
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China.
| | - Luying Xun
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China; School of Molecular Biosciences, Washington State University, Pullman, WA 99164-7520, USA.
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Mahajan SG, Nandre VS, Salunkhe RC, Shouche YS, Kulkarni MV. Chemotaxis and physiological adaptation of an indigenous abiotic stress tolerant plant growth promoting Pseudomonas stutzeri: Amelioration of salt stress to Cicer arietinum. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101652] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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3
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Guleria S, Joshi R, Singh D, Kumar S. Identification of host factors limiting the overexpression of recombinant Cu, Zn superoxide dismutase in Escherichia coli. Biotechnol Lett 2020; 42:2389-2401. [DOI: 10.1007/s10529-020-02962-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 07/03/2020] [Indexed: 11/24/2022]
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4
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Fan C, Davison PA, Habgood R, Zeng H, Decker CM, Gesell Salazar M, Lueangwattanapong K, Townley HE, Yang A, Thompson IP, Ye H, Cui Z, Schmidt F, Hunter CN, Huang WE. Chromosome-free bacterial cells are safe and programmable platforms for synthetic biology. Proc Natl Acad Sci U S A 2020; 117:6752-6761. [PMID: 32144140 PMCID: PMC7104398 DOI: 10.1073/pnas.1918859117] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
A type of chromosome-free cell called SimCells (simple cells) has been generated from Escherichia coli, Pseudomonas putida, and Ralstonia eutropha. The removal of the native chromosomes of these bacteria was achieved by double-stranded breaks made by heterologous I-CeuI endonuclease and the degradation activity of endogenous nucleases. We have shown that the cellular machinery remained functional in these chromosome-free SimCells and was able to process various genetic circuits. This includes the glycolysis pathway (composed of 10 genes) and inducible genetic circuits. It was found that the glycolysis pathway significantly extended longevity of SimCells due to its ability to regenerate ATP and NADH/NADPH. The SimCells were able to continuously express synthetic genetic circuits for 10 d after chromosome removal. As a proof of principle, we demonstrated that SimCells can be used as a safe agent (as they cannot replicate) for bacterial therapy. SimCells were used to synthesize catechol (a potent anticancer drug) from salicylic acid to inhibit lung, brain, and soft-tissue cancer cells. SimCells represent a simplified synthetic biology chassis that can be programmed to manufacture and deliver products safely without interference from the host genome.
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Affiliation(s)
- Catherine Fan
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom
| | - Paul A Davison
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Robert Habgood
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom
| | - Hong Zeng
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom
| | - Christoph M Decker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Manuela Gesell Salazar
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
| | | | - Helen E Townley
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom
| | - Aidong Yang
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom
| | - Ian P Thompson
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom
| | - Hua Ye
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom
| | - Zhanfeng Cui
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom
| | - Frank Schmidt
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
- Proteomics Core, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Wei E Huang
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, United Kingdom;
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5
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Cho B, Lee SH, Song J, Bhattacharjee S, Feng J, Hong S, Song M, Kim W, Lee J, Bang D, Wang B, Riley LW, Lee LP. Nanophotonic Cell Lysis and Polymerase Chain Reaction with Gravity-Driven Cell Enrichment for Rapid Detection of Pathogens. ACS NANO 2019; 13:13866-13874. [PMID: 31756079 DOI: 10.1021/acsnano.9b04685] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Rapid and precise detection of pathogens is a critical step in the prevention and identification of emergencies related to health and biosafety as well as the clinical management of community-acquired urinary tract infections or sexually transmitted diseases. However, a conventional culture-based pathogen diagnostic method is time-consuming, permitting physicians to use antibiotics without ample clinical data. Here, we present a nanophotonic Light-driven Integrated cell lysis and polymerase chain reaction (PCR) on a chip with Gravity-driven cell enrichment Health Technology (LIGHT) for rapid precision detection of pathogens (<20 min). We created the LIGHT, which has the three functions of (1) selective enrichment of pathogens, (2) photothermal cell lysis, and (3) photonic PCR on a chip. We designed the gravity-driven cell enrichment via a nanoporous membrane on a chip that allows an effective bacterial enrichment of 40 000-fold from a 1 mL sample in 2 min. We established a light-driven photothermal lysis of preconcentrated bacteria within 1 min by designing the network of nanoplasmonic optical antenna on a chip for ultrafast light-to-heat conversion, created the nanoplasmonic optical antenna network-based ultrafast photonic PCR on a chip, and identified Escherichia coli. Finally, we demonstrated the end-point detection of up to 103 CFU/mL of E. coli in 10 min. We believe that our nanophotonic LIGHT will provide rapid and precise identification of pathogens in both developing and developed countries.
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Affiliation(s)
- Byungrae Cho
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
- UC Berkeley and UCSF Joint Graduate Program in Bioengineering , University of California , Berkeley , California 94720 , United States
- Berkeley Sensor and Actuator Center , University of California , Berkeley , California 94720 , United States
| | - Sang Hun Lee
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
- Berkeley Sensor and Actuator Center , University of California , Berkeley , California 94720 , United States
| | - Jihwan Song
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
| | - Saptati Bhattacharjee
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
| | - Jeffrey Feng
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
| | - SoonGweon Hong
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
- Berkeley Sensor and Actuator Center , University of California , Berkeley , California 94720 , United States
| | - Minsun Song
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
- UC Berkeley and UCSF Joint Graduate Program in Bioengineering , University of California , Berkeley , California 94720 , United States
- Berkeley Sensor and Actuator Center , University of California , Berkeley , California 94720 , United States
| | - Wonseok Kim
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
- Berkeley Sensor and Actuator Center , University of California , Berkeley , California 94720 , United States
| | - Jonghwan Lee
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
- Berkeley Sensor and Actuator Center , University of California , Berkeley , California 94720 , United States
| | - Doyeon Bang
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
- Berkeley Sensor and Actuator Center , University of California , Berkeley , California 94720 , United States
| | - Bowen Wang
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
| | - Lee W Riley
- Division of Infectious Disease and Vaccinology, School of Public Health , University of California , Berkeley , California 94720 , United States
| | - Luke P Lee
- Department of Bioengineering , University of California , Berkeley , California 94720 , United States
- UC Berkeley and UCSF Joint Graduate Program in Bioengineering , University of California , Berkeley , California 94720 , United States
- Berkeley Sensor and Actuator Center , University of California , Berkeley , California 94720 , United States
- Department of Electrical Engineering and Computer Science , University of California , Berkeley , California 94720 , United States
- Biophysics Graduate Program , University of California , Berkeley , California 94720 , United States
- Biomedical Institute for Global Health Research and Technology (BIGHEART), Yong Loo Lin School of Medicine and Faculty of Engineering , National University of Singapore , Singapore 119077
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6
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Dwidar M, Yokobayashi Y. Riboswitch Signal Amplification by Controlling Plasmid Copy Number. ACS Synth Biol 2019; 8:245-250. [PMID: 30682247 DOI: 10.1021/acssynbio.8b00454] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Riboswitches are cis-acting RNA devices in mRNAs that control gene expression in response to chemical inputs. As RNA aptamers that recognize diverse classes of molecules can be isolated by in vitro selection, synthetic riboswitches hold promise for various applications in synthetic biology. One of the major drawbacks of riboswitches, however, is their limited dynamic range. A high level of gene expression in the OFF state (leakage) is also a common problem. To address these challenges, we designed and constructed a dual-riboswitch plasmid in which two genes are controlled by theophylline-activated riboswitches. One riboswitch controls the gene of interest, and another riboswitch controls RepL, a phage-derived replication protein that regulates the plasmid copy number. This single-plasmid system afforded an ON/OFF ratio as high as 3900. Furthermore, we used the system to control CRISPR interference (CRISPRi) targeting endogenous genes, and successfully observed expected phenotypic changes in Escherichia coli.
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Affiliation(s)
- Mohammed Dwidar
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495, Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495, Japan
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7
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Moon J, Kwak JI, An YJ. The effects of silver nanomaterial shape and size on toxicity to Caenorhabditis elegans in soil media. CHEMOSPHERE 2019; 215:50-56. [PMID: 30312916 DOI: 10.1016/j.chemosphere.2018.09.177] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 09/27/2018] [Accepted: 09/29/2018] [Indexed: 06/08/2023]
Abstract
Silver nanomaterials (AgNMs) of various shapes and sizes are manufactured for different purposes and used as ingredients in a wide variety of products and applications. Recently, the toxicity of AgNMs has attracted significant attention. However, the effect of the shape of AgNMs (particles, wires, plates) on their toxicity in soil ecosystems remains poorly understood. In this study, we added AgNMs of different shapes and sizes (silver nanoparticles, AgNPs; 10 μm silver nanowires, 10-AgNWs; 20 μm silver nanowires, 20-AgNWs; silver nanoplates, AgPLs) to natural soil and determined their effect on the growth and reproduction of the free-living nematode, Caenorhabditis elegans. AgNPs and AgPLs were found to inhibit the growth and reproduction of C. elegans, whereas AgNWs had a negligible effect. Among these AgNMs, the results of this study suggest AgNPs are the most toxic. This confirms that the shape of AgNPs plays a significant role in their toxicity level. To the best of our knowledge, this is the first comparative analysis of the shape-dependent toxicity of AgNMs in the soil using nematode C. elegans. This study provides a scientific reference for assessing shape-dependent soil nanotoxicity.
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Affiliation(s)
- Jongmin Moon
- Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Jin Il Kwak
- Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
| | - Youn-Joo An
- Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
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8
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A Markovian Approach towards Bacterial Size Control and Homeostasis in Anomalous Growth Processes. Sci Rep 2018; 8:9612. [PMID: 29942025 PMCID: PMC6018433 DOI: 10.1038/s41598-018-27748-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 06/04/2018] [Indexed: 11/26/2022] Open
Abstract
Regardless of the progress achieved during recent years, the mechanisms coupling growth and division to attain cell size homeostasis in bacterial populations are still not well understood. In particular, there is a gap of knowledge about the mechanisms controlling anomalous growth events that are ubiquitous even in wild-type phenotypes. Thus, when cells exceed the doubling size the divisome dynamics sets a characteristic length scale that suggests a sizer property. Yet, it has been recently shown that the size at birth and the size increment still satisfy an adder-like correlation. Herein we propose a Markov chain model, that we complement with computational and experimental approaches, to clarify this issue. In this context, we show that classifying cells as a function of the characteristic size set by the divisome dynamics provides a compelling framework to understand size convergence, growth, and division at the large length scale, including the adaptation to, and rescue from, filamentation processes. Our results reveal the independence of size homeostasis on the division pattern of long cells and help to reconcile sizer concepts at the single cell level with an adder-like behavior at a population level.
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9
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Cesar S, Huang KC. Thinking big: the tunability of bacterial cell size. FEMS Microbiol Rev 2017; 41:672-678. [PMID: 28961755 DOI: 10.1093/femsre/fux026] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 05/10/2017] [Indexed: 11/13/2022] Open
Abstract
The determination of cell size is a fundamental challenge for all living organisms. In a given growth condition, cell size for a particular bacterial species typically falls within a narrow distribution. Nonetheless, size can vary enormously across species, and the size of a single bacterium can even vary substantially across growth conditions. Recent phenomenological studies have revived classic interest in how cells maintain their size and how they adjust their size with changes in growth rate. However, the mechanisms by which cells establish a particular size are relatively enigmatic. Here, we review existing knowledge on how size in rod-shaped bacteria is shaped by nutrient, mechanical, and genetic factors. We also examine obstacles to accurate size measurement and recent technologies that help to overcome these hurdles. Finally, we discuss the relevance of cell size to bacterial physiology.
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Affiliation(s)
- Spencer Cesar
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kerwyn Casey Huang
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
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10
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Leppänen M, Sundberg LR, Laanto E, de Freitas Almeida GM, Papponen P, Maasilta IJ. Imaging Bacterial Colonies and Phage-Bacterium Interaction at Sub-Nanometer Resolution Using Helium-Ion Microscopy. ACTA ACUST UNITED AC 2017; 1:e1700070. [PMID: 32646179 DOI: 10.1002/adbi.201700070] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 06/01/2017] [Indexed: 11/11/2022]
Abstract
Imaging of microbial interactions has so far been based on well-established electron microscopy methods. This study presents a new way to study bacterial colonies and interactions between bacteria and their viruses, bacteriophages (phages), in situ on agar plates using helium ion microscopy (HIM). In biological imaging, HIM has advantages over traditional scanning electron microscopy with its sub-nanometer resolution, increased surface sensitivity, and the possibility to image nonconductive samples. Furthermore, by controlling the He beam dose or by using heavier Ne ions, the HIM instrument provides the possibility to mill out material in the samples, allowing for subsurface imaging and in situ sectioning. Here, the first HIM-images of bacterial colonies and phage-bacterium interactions are presented at different stages of the infection as they occur on an agar culture. The feasibility of neon and helium milling is also demonstrated to reveal the subsurface structures of bacterial colonies on agar substrate, and in some cases also structure inside individual bacteria after cross-sectioning. The study concludes that HIM offers great opportunities to advance the studies of microbial imaging, in particular in the area of interaction of viruses with cells.
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Affiliation(s)
- Miika Leppänen
- Nanoscience Center, Department of Physics, University of Jyvaskyla, P. O. Box 35, FI-40014, Jyväskylä, Finland.,Nanoscience Center, Center of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014, Jyväskylä, Finland
| | - Lotta-Riina Sundberg
- Nanoscience Center, Center of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014, Jyväskylä, Finland
| | - Elina Laanto
- Nanoscience Center, Center of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014, Jyväskylä, Finland
| | - Gabriel Magno de Freitas Almeida
- Nanoscience Center, Center of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014, Jyväskylä, Finland
| | - Petri Papponen
- Nanoscience Center, Center of Excellence in Biological Interactions, Department of Biological and Environmental Science, University of Jyvaskyla, FI-40014, Jyväskylä, Finland
| | - Ilari J Maasilta
- Nanoscience Center, Department of Physics, University of Jyvaskyla, P. O. Box 35, FI-40014, Jyväskylä, Finland
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11
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Elhadi D, Lv L, Jiang XR, Wu H, Chen GQ. CRISPRi engineering E. coli for morphology diversification. Metab Eng 2016; 38:358-369. [DOI: 10.1016/j.ymben.2016.09.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 08/21/2016] [Accepted: 09/11/2016] [Indexed: 01/09/2023]
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12
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Jahnke JP, Terrell JL, Smith AM, Cheng X, Stratis-Cullum DN. Influences of Adhesion Variability on the "Living" Dynamics of Filamentous Bacteria in Microfluidic Channels. Molecules 2016; 21:molecules21080985. [PMID: 27483214 PMCID: PMC6274349 DOI: 10.3390/molecules21080985] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 07/18/2016] [Accepted: 07/21/2016] [Indexed: 12/20/2022] Open
Abstract
Microfabricated devices have increasingly incorporated bacterial cells for microscale studies and exploiting cell-based functions in situ. However, the role of surface interactions in controlling the bacterial cell behavior is not well understood. In this study, microfluidic substrates of varied bacterial-binding affinity were used to probe the interaction-driven behavior of filamentous Escherichia coli. In particular, cell alignment under controlled shear flow as well as subsequent orientation and filamentation were compared between cells presenting distinct outer membrane phenotypes. We demonstrated that filaments retained position under flow, which allowed for dynamic single-cell monitoring with in situ elongation of over 100 μm for adherent cells. This maximum was not reached by planktonic cells and was, therefore, adhesion-dependent. The bound filaments initially aligned with flow under a range of flow rates and their continual elongation was traced in terms of length and growth path; analysis demonstrated that fimbriae-mediated adhesion increased growth rate, increased terminal length, as well as dramatically changed the adherent geometry, particularly buckling behavior. The effects to filament length and buckling were further exaggerated by the strongest, specificity-driven adhesion tested. Such surface-guided control of the elongation process may be valuable to yield interesting “living” filamentous structures in microdevices. In addition, this work may offer a biomedically relevant platform for further elucidation of filamentation as an immune-resistant morphology. Overall, this work should inspire broader exploration of microfabricated devices for the study and application of single bacterial cells.
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Affiliation(s)
| | | | | | - Xuanhong Cheng
- Department of Materials Science and Engineering, Bioengineering Program, Lehigh University, Bethlehem, PA 18015, USA.
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13
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Regulation of Growth, Cell Shape, Cell Division, and Gene Expression by Second Messengers (p)ppGpp and Cyclic Di-GMP in Mycobacterium smegmatis. J Bacteriol 2016; 198:1414-22. [PMID: 26903417 DOI: 10.1128/jb.00126-16] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 02/19/2016] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED The alarmone (p)ppGpp regulates transcription, translation, replication, virulence, lipid synthesis, antibiotic sensitivity, biofilm formation, and other functions in bacteria. Signaling nucleotide cyclic di-GMP (c-di-GMP) regulates biofilm formation, motility, virulence, the cell cycle, and other functions. In Mycobacterium smegmatis, both (p)ppGpp and c-di-GMP are synthesized and degraded by bifunctional proteins Rel(Msm) and DcpA, encoded by rel(Msm) and dcpA genes, respectively. We have previously shown that the Δrel(Msm) and ΔdcpA knockout strains are antibiotic resistant and defective in biofilm formation, show altered cell surface properties, and have reduced levels of glycopeptidolipids and polar lipids in their cell wall (K. R. Gupta, S. Kasetty, and D. Chatterji, Appl Environ Microbiol 81:2571-2578, 2015,http://dx.doi.org/10.1128/AEM.03999-14). In this work, we have explored the phenotypes that are affected by both (p)ppGpp and c-di-GMP in mycobacteria. We have shown that both (p)ppGpp and c-di-GMP are needed to maintain the proper growth rate under stress conditions such as carbon deprivation and cold shock. Scanning electron microscopy showed that low levels of these second messengers result in elongated cells, while high levels reduce the cell length and embed the cells in a biofilm-like matrix. Fluorescence microscopy revealed that the elongated Δrel(Msm) and ΔdcpA cells are multinucleate, while transmission electron microscopy showed that the elongated cells are multiseptate. Gene expression analysis also showed that genes belonging to functional categories such as virulence, detoxification, lipid metabolism, and cell-wall-related processes were differentially expressed. Our results suggests that both (p)ppGpp and c-di-GMP affect some common phenotypes in M. smegmatis, thus raising a possibility of cross talk between these two second messengers in mycobacteria. IMPORTANCE Our work has expanded the horizon of (p)ppGpp and c-di-GMP signaling in Gram-positive bacteria. We have come across a novel observation that M. smegmatis needs (p)ppGpp and c-di-GMP for cold tolerance. We had previously shown that the Δrel(Msm) and ΔdcpA strains are defective in biofilm formation. In this work, the overproduction of (p)ppGpp and c-di-GMP encased M. smegmatis in a biofilm-like matrix, which shows that both (p)ppGpp and c-di-GMP are needed for biofilm formation. The regulation of cell length and cell division by (p)ppGpp was known in mycobacteria, but our work shows that c-di-GMP also affects the cell size and cell division in mycobacteria. This is perhaps the first report of c-di-GMP regulating cell division in mycobacteria.
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14
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El-Hajj ZW, Newman EB. How much territory can a single E. coli cell control? Front Microbiol 2015; 6:309. [PMID: 25954251 PMCID: PMC4404868 DOI: 10.3389/fmicb.2015.00309] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 03/29/2015] [Indexed: 11/20/2022] Open
Abstract
Bacteria have been traditionally classified in terms of size and shape and are best known for their very small size. Escherichia coli cells in particular are small rods, each 1–2 μ. However, the size varies with the medium, and faster growing cells are larger because they must have more ribosomes to make more protoplasm per unit time, and ribosomes take up space. Indeed, Maaløe’s experiments on how E. coli establishes its size began with shifts between rich and poor media. Recently much larger bacteria have been described, including Epulopiscium fishelsoni at 700 μm and Thiomargarita namibiensis at 750 μm. These are not only much longer than E. coli cells but also much wider, necessitating considerable intracellular organization. Epulopiscium cells for instance, at 80 μm wide, enclose a large enough volume of cytoplasm to present it with major transport problems. This review surveys E. coli cells much longer than those which grow in nature and in usual lab cultures. These include cells mutated in a single gene (metK) which are 2–4 × longer than their non-mutated parent. This metK mutant stops dividing when slowly starved of S-adenosylmethionine but continues to elongate to 50 μm and more. FtsZ mutants have been routinely isolated as long cells which form during growth at 42°C. The SOS response is a well-characterized regulatory network that is activated in response to DNA damage and also results in cell elongation. Our champion elongated E. coli is a metK strain with a further, as yet unidentified mutation, which reaches 750 μm with no internal divisions and no increase in width.
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Affiliation(s)
- Ziad W El-Hajj
- Department of Biology, Concordia University , Montreal, QC, Canada
| | - Elaine B Newman
- Department of Biology, Concordia University , Montreal, QC, Canada
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