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Worthan SB, McCarthy RDP, Delaleau M, Stikeleather R, Bratton BP, Boudvillain M, Behringer MG. Evolution of pH-sensitive transcription termination during adaptation to repeated long-term starvation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.01.582989. [PMID: 38464051 PMCID: PMC10925284 DOI: 10.1101/2024.03.01.582989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Fluctuating environments that consist of regular cycles of co-occurring stress are a common challenge faced by cellular populations. For a population to thrive in constantly changing conditions, an ability to coordinate a rapid cellular response is essential. Here, we identify a mutation conferring an arginine-to-histidine (Arg to His) substitution in the transcription terminator Rho. The rho R109H mutation frequently arose in E. coli populations experimentally evolved under repeated long-term starvation conditions, during which feast and famine result in drastic environmental pH fluctuations. Metagenomic sequencing revealed that populations containing the rho mutation also possess putative loss-of-function mutations in ydcI, which encodes a recently characterized transcription factor associated with pH homeostasis. Genetic reconstructions of these mutations show that the rho allele confers a plastic alkaline-induced reduction of Rho function that, when found in tandem with a ΔydcI allele, leads to intracellular alkalinization and genetic assimilation of Rho mutant function. We further identify Arg to His substitutions at analogous sites in rho alleles from species originating from fluctuating alkaline environments. Our results suggest that Arg to His substitutions in global regulators of gene expression can serve to rapidly coordinate complex responses through pH sensing and shed light on how cellular populations across the tree of life use environmental cues to coordinate rapid responses to complex, fluctuating environments.
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Affiliation(s)
- Sarah B Worthan
- Department of Biological Sciences, Vanderbilt University, Nashville, TN
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN
- Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, TN
| | | | - Mildred Delaleau
- Centre de Biophysique Moléculaire, CNRS UPR4301, affiliated with Université d'Orléans, rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Ryan Stikeleather
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ
| | - Benjamin P Bratton
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN
- Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, TN
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
| | - Marc Boudvillain
- Centre de Biophysique Moléculaire, CNRS UPR4301, affiliated with Université d'Orléans, rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Megan G Behringer
- Department of Biological Sciences, Vanderbilt University, Nashville, TN
- Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN
- Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, TN
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ
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2
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Boudreau BA, Hustmyer CM, Kotlajich MV, Landick R. In Vitro Transcription Assay to Quantify Effects of H-NS Filaments on RNA Chain Elongation by RNA Polymerase. Methods Mol Biol 2024; 2819:381-419. [PMID: 39028516 DOI: 10.1007/978-1-0716-3930-6_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Bacterial chromosomal DNA is structured and compacted by proteins known as bacterial chromatin proteins (i.e., nucleoid-associated proteins or NAPs). DNA-dependent RNA polymerase (RNAP) must frequently interact with bacterial chromatin proteins because they often bind DNA genome-wide. In some cases, RNAP must overcome barriers bacterial chromatin proteins impose on transcription. One key bacterial chromatin protein in Escherichia coli that influences transcription is the histone-like nucleoid structuring protein, H-NS. H-NS binds to DNA and forms nucleoprotein filaments. To investigate the effect of H-NS filaments on RNAP elongation, we developed an in vitro transcription assay to monitor RNAP progression on a DNA template bound by H-NS. In this method, initiation and elongation by RNAP are uncoupled by first initiating transcription in the presence of only three ribonucleoside triphosphates (rNTPs) to halt elongation just downstream of the promoter. Before elongation is restarted by addition of the fourth NTP, an H-NS filament is formed on the DNA so that transcript elongation occurs on an H-NS nucleoprotein filament template. Here, we provide detailed protocols for performing in vitro transcription through H-NS filaments, analysis of the transcription products, and visualization of H-NS filament formation on DNA by electrophoretic mobility shift assay (EMSA). These methods enable insight into how H-NS affects RNAP transcript elongation and provide a starting point to determine effects of other bacterial chromatin proteins on RNAP elongation.
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Affiliation(s)
- Beth A Boudreau
- Departments of Biochemistry, University of Wisconsin - Madison, Madison, WI, USA
| | - Christine M Hustmyer
- Departments of Biochemistry, University of Wisconsin - Madison, Madison, WI, USA
| | - Matthew V Kotlajich
- Departments of Biochemistry, University of Wisconsin - Madison, Madison, WI, USA
| | - Robert Landick
- Departments of Biochemistry, University of Wisconsin - Madison, Madison, WI, USA.
- Departments of Bacteriology, University of Wisconsin - Madison, Madison, WI, USA.
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3
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Gao S, Liao Y, He H, Yang H, Yang X, Xu S, Wang X, Chen K, Ouyang P. Advance of tolerance engineering on microbes for industrial production. Synth Syst Biotechnol 2023; 8:697-707. [PMID: 38025766 PMCID: PMC10656194 DOI: 10.1016/j.synbio.2023.10.004] [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: 08/27/2023] [Revised: 10/19/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Industrial microbes have become the core of biological manufacturing, which utilized as the cell factory for production of plenty of chemicals, fuels and medicine. However, the challenge that the extreme stress conditions exist in production is unavoidable for cell factory. Consequently, to enhance robustness of the chassis cell lays the foundation for development of bio-manufacturing. Currently, the researches on cell tolerance covered various aspects, involving reshaping regulatory network, cell membrane modification and other stress response. In fact, the strategies employed to improve cell robustness could be summarized into two directions, irrational engineering and rational engineering. In this review, the metabolic engineering technologies on enhancement of microbe tolerance to industrial conditions are summarized. Meanwhile, the novel thoughts emerged with the development of biological instruments and synthetic biology are discussed.
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Affiliation(s)
- Siyuan Gao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Yang Liao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Hao He
- Petrochemical Research Institute of PetroChina Co. Ltd., Beijing, 102206, China
| | - Huiling Yang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Xuewei Yang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Sheng Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Xin Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Kequan Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
| | - Pingkai Ouyang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211816, Jiangsu, China
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4
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Rizavi HS, Gavin HE, Krishnan HR, Gavin DP, Sharma RP. Ethanol- and PARP-Mediated Regulation of Ribosome-Associated Long Non-Coding RNA (lncRNA) in Pyramidal Neurons. Noncoding RNA 2023; 9:72. [PMID: 37987368 PMCID: PMC10661276 DOI: 10.3390/ncrna9060072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/23/2023] [Accepted: 11/03/2023] [Indexed: 11/22/2023] Open
Abstract
Although, by definition, long noncoding RNAs (lncRNAs) are not translated, they are sometimes associated with ribosomes. In fact, some estimates suggest the existence of more than 50 K lncRNA molecules that could encode for small peptides. We examined the effects of an ethanol and Poly-ADP Ribose Polymerase (PARP) inhibitor (ABT-888) on ribosome-bound lncRNAs. Mice were administered via intraperitoneal injection (i.p.) either normal saline (CTL) or ethanol (EtOH) twice a day for four consecutive days. On the fourth day, a sub-group of mice administered with ethanol also received ABT-888 (EtOH+ABT). Ribosome-bound lncRNAs in CaMKIIα-expressing pyramidal neurons were measured using the Translating Ribosome Affinity Purification (TRAP) technique. Our findings show that EtOH altered the attachment of 107 lncRNA transcripts, while EtOH+ABT altered 60 lncRNAs. Among these 60 lncRNAs, 49 were altered by both conditions, while EtOH+ABT uniquely altered the attachment of 11 lncRNA transcripts that EtOH alone did not affect. To validate these results, we selected eight lncRNAs (Mir124-2hg, 5430416N02Rik, Snhg17, Snhg12, Snhg1, Mir9-3hg, Gas5, and 1110038B12Rik) for qRT-PCR analysis. The current study demonstrates that ethanol-induced changes in lncRNA attachment to ribosomes can be mitigated by the addition of the PARP inhibitor ABT-888.
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Affiliation(s)
- Hooriyah S. Rizavi
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA; (H.S.R.); (H.E.G.)
- Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA
| | - Hannah E. Gavin
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA; (H.S.R.); (H.E.G.)
| | - Harish R. Krishnan
- Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA;
| | - David P. Gavin
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA; (H.S.R.); (H.E.G.)
| | - Rajiv P. Sharma
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA; (H.S.R.); (H.E.G.)
- Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA
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5
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Oh E, Choi SJ, Han S, Lee KH, Choi HJ. Highly Effective Salt-Activated Alcohol-Based Disinfectants with Enhanced Antimicrobial Activity. ACS NANO 2023; 17:17811-17825. [PMID: 37639494 DOI: 10.1021/acsnano.3c03315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Surfaces contaminated with pathogens raise concerns about the increased risk of disease transmission and infection. To clean biocontaminated surfaces, alcohol-based disinfectants have been predominantly used for disinfecting high-touch areas in diverse settings. However, due to its limited antimicrobial activities and concern over the emergence of alcohol-tolerant strains, much effort has been made to develop highly efficient disinfectant formulations. In this study, we hypothesize that the addition of a physical pathogen inactivation mechanism by salt recrystallization (besides the existing chemical inactivation mechanism by alcohol in such formulations) can improve inactivation efficiency by preventing the emergence of alcohol tolerance. To this end, we employed the drying-induced salt recrystallization process to implement the concept of highly efficient alcohol-based disinfectant formulations. To identify the individual and combined effects of isopropyl alcohol (IPA) and NaCl, time-dependent morphological/structural changes of various IPA solutions containing NaCl have been characterized by optical microscopy/X-ray diffraction analysis. Their antimicrobial activities have been tested on surfaces (glass slide, polystyrene Petri dish, and stainless steel) contaminated with Gram-positive/negative bacteria (methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica subsp. enterica Typhimurium) and viruses (A/PR8/34 H1N1 influenza virus and HCoV-OC43 human coronavirus). We found that additional salt crystallization during the drying of the alcohol solution facilitated stronger biocidal effects than IPA-only formulations, regardless of the types of solid surfaces and pathogens, including alcohol-tolerant strains adapted from wild-type Escherichia coli MG1655. Our findings can be useful in developing highly effective disinfectant formulations by minimizing the use of toxic antimicrobial substances to improve public health and safety.
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Affiliation(s)
- Euna Oh
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Seung Joon Choi
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Sumin Han
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
| | - Kyu Hyoung Lee
- Department of Materials Science and Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Hyo-Jick Choi
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada
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6
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Olson DG, Maloney MI, Lanahan AA, Cervenka ND, Xia Y, Pech-Canul A, Hon S, Tian L, Ziegler SJ, Bomble YJ, Lynd LR. Ethanol tolerance in engineered strains of Clostridium thermocellum. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:137. [PMID: 37710260 PMCID: PMC10503014 DOI: 10.1186/s13068-023-02379-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 08/05/2023] [Indexed: 09/16/2023]
Abstract
Clostridium thermocellum is a natively cellulolytic bacterium that is promising candidate for cellulosic biofuel production, and can produce ethanol at high yields (75-80% of theoretical) but the ethanol titers produced thus far are too low for commercial application. In several strains of C. thermocellum engineered for increased ethanol yield, ethanol titer seems to be limited by ethanol tolerance. Previous work to improve ethanol tolerance has focused on the WT organism. In this work, we focused on understanding ethanol tolerance in several engineered strains of C. thermocellum. We observed a tradeoff between ethanol tolerance and production. Adaptation for increased ethanol tolerance decreases ethanol production. Second, we observed a consistent genetic response to ethanol stress involving mutations at the AdhE locus. These mutations typically reduced NADH-linked ADH activity. About half of the ethanol tolerance phenotype could be attributed to the elimination of NADH-linked activity based on a targeted deletion of adhE. Finally, we observed that rich growth medium increases ethanol tolerance, but this effect is eliminated in an adhE deletion strain. Together, these suggest that ethanol inhibits growth and metabolism via a redox-imbalance mechanism. The improved understanding of mechanisms of ethanol tolerance described here lays a foundation for developing strains of C. thermocellum with improved ethanol production.
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Affiliation(s)
- Daniel G Olson
- Thayer School of Engineering at Dartmouth College, Hanover, NH, 03755, USA.
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
| | - Marybeth I Maloney
- Thayer School of Engineering at Dartmouth College, Hanover, NH, 03755, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Anthony A Lanahan
- Thayer School of Engineering at Dartmouth College, Hanover, NH, 03755, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Nicholas D Cervenka
- Thayer School of Engineering at Dartmouth College, Hanover, NH, 03755, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Ying Xia
- Thayer School of Engineering at Dartmouth College, Hanover, NH, 03755, USA
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China
| | - Angel Pech-Canul
- Thayer School of Engineering at Dartmouth College, Hanover, NH, 03755, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Shuen Hon
- Thayer School of Engineering at Dartmouth College, Hanover, NH, 03755, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Liang Tian
- Thayer School of Engineering at Dartmouth College, Hanover, NH, 03755, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
- Youth Olympic Village, #1-1-602, Jianye District, Nanjing, Jiangsu, China
| | - Samantha J Ziegler
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Yannick J Bomble
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Lee R Lynd
- Thayer School of Engineering at Dartmouth College, Hanover, NH, 03755, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
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7
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Wang B, Said N, Hilal T, Finazzo M, Wahl MC, Artsimovitch I. Transcription termination factor ρ polymerizes under stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.18.553922. [PMID: 37645988 PMCID: PMC10462130 DOI: 10.1101/2023.08.18.553922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Bacterial RNA helicase ρ is a genome sentinel that terminates synthesis of damaged and junk RNAs that are not translated by the ribosome. Co-transcriptional RNA surveillance by ρ is essential for quality control of the transcriptome during optimal growth. However, it is unclear how bacteria protect their RNAs from overzealous ρ during dormancy or stress, conditions common in natural habitats. Here we used cryogenic electron microscopy, biochemical, and genetic approaches to show that residue substitutions, ADP, or ppGpp promote hyper-oligomerization of Escherichia coli ρ. Our results demonstrate that nucleotides bound at subunit interfaces control ρ switching from active hexamers to inactive higher-order oligomers and extended filaments. Polymers formed upon exposure to antibiotics or ppGpp disassemble when stress is relieved, thereby directly linking termination activity to cellular physiology. Inactivation of ρ through hyper-oligomerization is a regulatory strategy shared by RNA polymerases, ribosomes, and metabolic enzymes across all life.
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Affiliation(s)
- Bing Wang
- Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Nelly Said
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of Structural Biochemistry, Takustr. 6, D-14195 Berlin, Germany
| | - Tarek Hilal
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of Structural Biochemistry, Takustr. 6, D-14195 Berlin, Germany
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Research Center of Electron Microscopy and Core Facility BioSupraMol, Fabeckstr. 36a, 14195 Berlin, Germany
| | - Mark Finazzo
- Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Markus C. Wahl
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Laboratory of Structural Biochemistry, Takustr. 6, D-14195 Berlin, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Albert-Einstein-Str. 15, D-12489 Berlin, Germany
| | - Irina Artsimovitch
- Department of Microbiology and Center for RNA Biology, The Ohio State University, Columbus, OH, USA
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Pasotti L, De Marchi D, Casanova M, Frusteri Chiacchiera A, Cusella De Angelis MG, Calvio C, Magni P. Design of a stable ethanologenic bacterial strain without heterologous plasmids and antibiotic resistance genes for efficient ethanol production from concentrated dairy waste. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:57. [PMID: 37005680 PMCID: PMC10067303 DOI: 10.1186/s13068-023-02298-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 03/03/2023] [Indexed: 04/04/2023]
Abstract
Engineering sustainable bioprocesses that convert abundant waste into fuels is pivotal for efficient production of renewable energy. We previously engineered an Escherichia coli strain for optimized bioethanol production from lactose-rich wastewater like concentrated whey permeate (CWP), a dairy effluent obtained from whey valorization processes. Although attractive fermentation performances were reached, significant improvements are required to eliminate recombinant plasmids, antibiotic resistances and inducible promoters, and increase ethanol tolerance. Here, we report a new strain with chromosomally integrated ethanologenic pathway under the control of a constitutive promoter, without recombinant plasmids and resistance genes. The strain showed extreme stability in 1-month subculturing, with CWP fermentation performances similar to the ethanologenic plasmid-bearing strain. We then investigated conditions enabling efficient ethanol production and sugar consumption by changing inoculum size and CWP concentration, revealing toxicity- and nutritional-related bottlenecks. The joint increase of ethanol tolerance, via adaptive evolution, and supplementation of small ammonium sulphate amounts (0.05% w/v) enabled a fermentation boost with 6.6% v/v ethanol titer, 1.2 g/L/h rate, 82.5% yield, and cell viability increased by three orders of magnitude. Our strain has attractive features for industrial settings and represents a relevant improvement in the existing ethanol production biotechnologies.
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Affiliation(s)
- Lorenzo Pasotti
- Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy.
- Centre for Health Technologies, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy.
| | - Davide De Marchi
- Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy
- Centre for Health Technologies, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy
| | - Michela Casanova
- Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy
- Centre for Health Technologies, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy
| | - Angelica Frusteri Chiacchiera
- Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy
- Centre for Health Technologies, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy
| | - Maria Gabriella Cusella De Angelis
- Centre for Health Technologies, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy
- Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Via Forlanini 8, 27100, Pavia, Italy
| | - Cinzia Calvio
- Centre for Health Technologies, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy
- Department of Biology and Biotechnology, University of Pavia, Via Ferrata 9, 27100, Pavia, Italy
| | - Paolo Magni
- Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy
- Centre for Health Technologies, University of Pavia, Via Ferrata 5, 27100, Pavia, Italy
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9
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Alonso VPP, Gonçalves MPMBB, de Brito FAE, Barboza GR, Rocha LDO, Silva NCC. Dry surface biofilms in the food processing industry: An overview on surface characteristics, adhesion and biofilm formation, detection of biofilms, and dry sanitization methods. Compr Rev Food Sci Food Saf 2023; 22:688-713. [PMID: 36464983 DOI: 10.1111/1541-4337.13089] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 11/14/2022] [Accepted: 11/18/2022] [Indexed: 12/09/2022]
Abstract
Bacterial biofilm formation in low moisture food processing (LMF) plants is related to matters of food safety, production efficiency, economic loss, and reduced consumer trust. Dry surfaces may appear dry to the naked eye, however, it is common to find a coverage of thin liquid films and microdroplets, known as microscopic surface wetness (MSW). The MSW may favor dry surface biofilm (DSB) formation. DSB formation is similar in other industries, it occurs through the processes of adhesion, production of extracellular polymeric substances, development of microcolonies and maturation, it is mediated by a quorum sensing (QS) system and is followed by dispersal, leading to disaggregation. Species that survive on dry surfaces develop tolerance to different stresses. DSB are recalcitrant and contribute to higher resistance to sanitation, becoming potential sources of contamination, related to the spoilage of processed products and foodborne disease outbreaks. In LMF industries, sanitization is performed using physical methods without the presence of water. Although alternative dry sanitizing methods can be efficiently used, additional studies are still required to develop and assess the effect of emerging technologies, and to propose possible combinations with traditional methods to enhance their effects on the sanitization process. Overall, more information about the different technologies can help to find the most appropriate method/s, contributing to the development of new sanitization protocols. Thus, this review aimed to identify the main characteristics and challenges of biofilm management in low moisture food industries, and summarizes the mechanisms of action of different dry sanitizing methods (alcohol, hot air, UV-C light, pulsed light, gaseous ozone, and cold plasma) and their effects on microbial metabolism.
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Affiliation(s)
- Vanessa Pereira Perez Alonso
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Maria Paula M B B Gonçalves
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | | | - Giovana Rueda Barboza
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
| | - Liliana de Oliveira Rocha
- Department of Food Science and Nutrition, School of Food Engineering, University of Campinas, Campinas, SP, Brazil
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10
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Blood Vessels as a Key Mediator for Ethanol Toxicity: Implication for Neuronal Damage. LIFE (BASEL, SWITZERLAND) 2022; 12:life12111882. [PMID: 36431016 PMCID: PMC9696276 DOI: 10.3390/life12111882] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 11/10/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022]
Abstract
Excessive intake of ethanol is associated with severe brain dysfunction, and the subsequent neurological and behavioral abnormalities are well-established social risks. Many research studies have addressed how ethanol induces neurological toxicity. However, the underlying mechanisms with which ethanol induces neurological toxicity are still obscure, perhaps due to the variety and complexity of these mechanisms. Epithelial cells are in direct contact with blood and can thus mediate ethanol neurotoxicity. Ethanol activates the endothelial cells of blood vessels, as well as lymphatic vessels, in a concentration-dependent manner. Among various signaling mediators, nitric oxide plays important roles in response to ethanol. Endothelial and inducible nitric oxide synthases (eNOS and iNOS) are upregulated and activated by ethanol and enhance neuroinflammation. On the other hand, angiogenesis and blood vessel remodeling are both affected by ethanol intake, altering blood supply and releasing angiocrine factors to regulate neuronal functions. Thus, ethanol directly acts on endothelial cells, yet the molecular target(s) on endothelial cells remain unknown. Previous studies on neurons and glial cells have validated the potential contribution of membrane lipids and some specific proteins as ethanol targets, which may also be the case in endothelial cells. Future studies, based on current knowledge, will allow for a greater understanding of the contribution and underlying mechanisms of endothelial cells in ethanol-induced neurological toxicity, protecting neurological health against ethanol toxicity.
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11
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Wallelign TM, Selam MN, Wondie GB, Habte BM. Assessment of compliance to packaging and labeling regulatory requirements of locally manufactured alcohol-based hand sanitizers marketed in Addis Ababa, Ethiopia. J Pharm Policy Pract 2022; 15:60. [PMID: 36217176 PMCID: PMC9550303 DOI: 10.1186/s40545-022-00456-6] [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: 04/11/2022] [Accepted: 10/02/2022] [Indexed: 11/17/2022] Open
Abstract
Background Following the emergence of the global Coronavirus Disease-2019 (COVID-19) pandemic, alcohol-based hand sanitizers (ABHS) have been extensively used as one of the effective methods of preventing its transmission. The products are dispensed over the counter and used by the general population. Growing concerns have been reported, however, regarding the quality, efficacy and compliance to regulatory requirements calling for objective evidence that can facilitate proactive regulatory measures. Objectives The study aimed at assessing the level of compliance to packaging and labeling regulatory requirements of selected locally manufactured ABHS products marketed in Addis Ababa, Ethiopia. Methods A cross-sectional study design was employed to randomly collect 25 locally manufactured ABHS products from retail outlets located in Addis Ababa. The manufacturers were grouped under four categories considering their experience in manufacturing, resources and technical capacities. The collected samples were evaluated for compliance to packaging and labeling information regulatory requirements and the results subjected to descriptive analysis. Results Majority of the products were found to meet most of the packaging, general product description and manufacturer-related information requirements. However, concerning gaps were observed in storage, precaution and warning-related labeling information requirements. The overall compliance of the selected products (to a total of 29 requirements under 5 categories) was 56.9%. The highest level of compliance was for general product information requirements (80.2%) followed by packaging and manufacturer-related requirements accounting for 76.8% and 75.0%, respectively. Low level of compliance was observed for storage condition and precautions (10.2% and 42.4%, respectively). Better overall compliance to packaging and labeling requirements (62.9%) were observed by large pharmaceutical and cosmetics manufacturers, while the lowest compliance level was recorded for medium level pharmaceuticals and cosmetics manufacturers. Conclusions Even though most of the selected products were able to comply with the majority of packaging, product description and manufacturer-related requirements, gaps were observed in essential labeling information requirements. Considering the extensive use of ABHS products among diverse population groups and the potential risks associated with inappropriate use of the products, improving regulatory law enforcement practices, strengthening continuing education of manufacturing personnel and raising public awareness is very timely. Supplementary Information The online version contains supplementary material available at 10.1186/s40545-022-00456-6.
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Affiliation(s)
- Tesfa Marew Wallelign
- Department of Pharmaceutics and Social Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, P.O. Box: 9086, Addis Ababa, Ethiopia
| | - Muluken Nigatu Selam
- Department of Pharmaceutics and Social Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, P.O. Box: 9086, Addis Ababa, Ethiopia
| | - Gebremariam Birhanu Wondie
- Department of Pharmaceutics and Social Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, P.O. Box: 9086, Addis Ababa, Ethiopia.,Department of Pharmacology, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
| | - Bruck Messele Habte
- Department of Pharmaceutics and Social Pharmacy, School of Pharmacy, College of Health Sciences, Addis Ababa University, P.O. Box: 9086, Addis Ababa, Ethiopia.
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12
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Xiao S, Yuan Z, Huang Y. Disinfectants against SARS-CoV-2: A Review. Viruses 2022; 14:v14081721. [PMID: 36016342 PMCID: PMC9413547 DOI: 10.3390/v14081721] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/22/2022] [Accepted: 08/01/2022] [Indexed: 11/16/2022] Open
Abstract
The pandemic due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has emerged as a serious global public health issue. Besides the high transmission rate from individual to individual, indirect transmission from inanimate objects or surfaces poses a more significant threat. Since the start of the outbreak, the importance of respiratory protection, social distancing, and chemical disinfection to prevent the spread of the virus has been the prime focus for infection control. Health regulatory organizations have produced guidelines for the formulation and application of chemical disinfectants to manufacturing industries and the public. On the other hand, extensive literature on the virucidal efficacy testing of microbicides for SARS-CoV-2 has been published over the past year and a half. This review summarizes the studies on the most common chemical disinfectants and their virucidal efficacy against SARS-CoV-2, including the type and concentration of the chemical disinfectant, the formulation, the presence of excipients, the exposure time, and other critical factors that determine the effectiveness of chemical disinfectants. In this review, we also critically appraise these disinfectants and conduct a discussion on the role they can play in the COVID-19 pandemic.
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Affiliation(s)
- Shuqi Xiao
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430020, China
| | - Zhiming Yuan
- National Biosafety Laboratory, Chinese Academy of Sciences, Wuhan 430020, China
| | - Yi Huang
- National Biosafety Laboratory, Chinese Academy of Sciences, Wuhan 430020, China
- Correspondence:
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13
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Sun Q, Gao S, Yu S, Zheng P, Zhou J. Production of (2S)-sakuranetin from (2S)-naringenin in Escherichia coli by strengthening methylation process and cell resistance. Synth Syst Biotechnol 2022; 7:1117-1125. [PMID: 36017331 PMCID: PMC9399173 DOI: 10.1016/j.synbio.2022.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/15/2022] Open
Abstract
(2S)-Sakuranetin is a 7-O-methylflavonoid that has anticancer, antiviral, and antimicrobial activities. Methylation process is involved in biosynthesizing (2S)-sakuranetin from (2S)-naringenin, in which S-adenosylmethionine (SAM) serves as the methyl donor. In this study, after methyl donor and substrate inhibition were identified as limiting factors for (2S)-sakuranetin biosynthesis, an efficient (2S)-sakuranetin-producing strain was constructed by enhancing methyl donor supply and cell tolerance to (2S)-naringenin. Firstly, PfOMT3 from Perilla frutescens was selected as the optimal flavonoid 7-O-methyltransferase (F7-OMT) for the conversion of (2S)-naringenin to (2S)-sakuranetin. Then, the methylation process was upregulated by regulating pyridoxal 5′-phosphate (PLP) content, key enzymes in methionine synthesis pathway, and the availability of ATP. Furthermore, genes that can enhance cell resistance to (2S)-naringenin were identified from molecular chaperones and sRNAs. Finally, by optimizing the fermentation process, 681.44 mg/L of (2S)-sakuranetin was obtained in 250-mL shake flasks. The titer of (2S)-sakuranetin reached 2642.38 mg/L in a 5-L bioreactor, which is the highest titer ever reported. This work demonstrates the importance of cofactor PLP in methylation process, and provides insights to biosynthesize other O-methylated flavonoids efficiently in E. coli.
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Affiliation(s)
- Qiumeng Sun
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Song Gao
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Shiqin Yu
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Pu Zheng
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Corresponding author. School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.
| | - Jingwen Zhou
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Engineering Research Center of Ministry of Education on Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, Wuxi, 214122, China
- Corresponding author. Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu, 214122, China.
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14
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Muleba L, Van Wyk R, Pienaar J, Ratshikhopha E, Singh T. Assessment of Anti-Bacterial Effectiveness of Hand Sanitizers Commonly Used in South Africa. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19159245. [PMID: 35954594 PMCID: PMC9367797 DOI: 10.3390/ijerph19159245] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 02/06/2023]
Abstract
Hand sanitizers are used as an alternative to hand washing to reduce the number of viable microorganisms when soap and water are not readily available. This study aimed to investigate the anti-bacterial effectiveness of commercially available hand sanitizers and those commonly used in healthcare and community settings. A mapping exercise was done to select and procure different hand sanitizers (n = 18) from retailers. Five microorganisms implicated in hospital-acquired infections were selected and tested against each hand sanitizer: Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Twenty-one volunteers were recruited to do a handprint before and after applying the hand sanitizer. Only four out of eighteen hand sanitizers (22%) were effective against all tested bacterial species, and an equal number (22%) were completely ineffective. Seven hand sanitizers with a label claim of 99.99% were only effective against E. coli. Only five hand sanitizers (27%) effectively reduced bacteria on participants’ hands. This study showed that only a fifth of hand sanitizers were effective against selected microorganisms. The findings raise a concern about the effectiveness of hand sanitizers and their role in infection, prevention, and control if not well regulated.
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Affiliation(s)
- Lufuno Muleba
- National Institute for Occupational Health, National Health Laboratory Service, Johannesburg 2000, South Africa; (L.M.); (E.R.)
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2028, South Africa
| | - Renay Van Wyk
- Department of Environmental Health, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2028, South Africa;
| | - Jennifer Pienaar
- Biomedical Sciences, Faculty of Health and Life Sciences, De Montfort University, Leicester LE1 9BH, UK;
| | - Edith Ratshikhopha
- National Institute for Occupational Health, National Health Laboratory Service, Johannesburg 2000, South Africa; (L.M.); (E.R.)
| | - Tanusha Singh
- National Institute for Occupational Health, National Health Laboratory Service, Johannesburg 2000, South Africa; (L.M.); (E.R.)
- Department of Environmental Health, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2028, South Africa;
- Department of Clinical Microbiology and Infectious Diseases, University of Witwatersrand, Johannesburg 2050, South Africa
- Correspondence:
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15
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Wang W, Rahman A, Huang Q, Vikesland PJ. Surface-enhanced Raman spectroscopy enabled evaluation of bacterial inactivation. WATER RESEARCH 2022; 220:118668. [PMID: 35689895 DOI: 10.1016/j.watres.2022.118668] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/21/2022] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
An improved understanding of bacterial inactivation mechanisms will provide useful insights for infectious disease control and prevention. We evaluated bacterial response to several inactivation methods using surface-enhanced Raman spectroscopy (SERS). The results indicate that changes in the SERS signal are highly related to cellular disruption and that cellular changes arising after cell inactivation cannot be ignored. The membrane integrity of heat and the combination of UV254 and free chlorine (UV254/chlorine) treated Pseudomonas syringae (P. syringae) cells were severely disrupted, leading to significantly increased peak intensities. Conversely, ethanol treated bacteria exhibited intact cell morphologies and the SERS spectra remained virtually unchanged. On the basis of time dependent SERS signals, we extracted dominant SERS patterns. Peaks related to nucleic acids accounted for the main changes observed during heat, UV254, and UV254/chlorine treatment, likely due to their outward diffusion from the cell cytoplasm. For free chlorine treated P. syringae, carbohydrates and proteins on the cell membrane were denatured or lost, resulting in a decrease in related peak intensities. The nucleobases were likely oxidized when treated with UV254 and chlorine, thus leading to shifts in the related peaks. The generality of the method was verified using two additional bacterial strains: Escherichia coli and Bacillus subtilis as well as in different water matrices. The results suggest that SERS spectral analysis is a promising means to examine bacterial stress response at the molecular level and has applicability in diverse environmental implementations.
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Affiliation(s)
- Wei Wang
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA; Virginia Tech Institute of Critical Technology and Applied Science (ICTAS) Sustainable Nanotechnology Center (VTSuN), Blacksburg, Virginia 24061, USA
| | - Asifur Rahman
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA; Virginia Tech Institute of Critical Technology and Applied Science (ICTAS) Sustainable Nanotechnology Center (VTSuN), Blacksburg, Virginia 24061, USA
| | - Qishen Huang
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA; Virginia Tech Institute of Critical Technology and Applied Science (ICTAS) Sustainable Nanotechnology Center (VTSuN), Blacksburg, Virginia 24061, USA
| | - Peter J Vikesland
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA; Virginia Tech Institute of Critical Technology and Applied Science (ICTAS) Sustainable Nanotechnology Center (VTSuN), Blacksburg, Virginia 24061, USA.
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16
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Bacterial H-NS contacts DNA at the same irregularly spaced sites in both bridged and hemi-sequestered linear filaments. iScience 2022; 25:104429. [PMID: 35669520 PMCID: PMC9162952 DOI: 10.1016/j.isci.2022.104429] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/01/2022] [Accepted: 05/13/2022] [Indexed: 11/22/2022] Open
Abstract
Gene silencing in bacteria is mediated by chromatin proteins, of which Escherichia coli H-NS is a paradigmatic example. H-NS forms nucleoprotein filaments with either one or two DNA duplexes. However, the structures, arrangements of DNA-binding domains (DBDs), and positions of DBD-DNA contacts in linear and bridged filaments are uncertain. To characterize the H-NS DBD contacts that silence transcription by RNA polymerase, we combined ·OH footprinting, molecular dynamics, statistical modeling, and DBD mapping using a chemical nuclease (Fe2+-EDTA) tethered to the DBDs (TEN-map). We find that H-NS DBDs contact DNA at indistinguishable locations in bridged or linear filaments and that the DBDs vary in orientation and position with ∼10-bp average spacing. Our results support a hemi-sequestration model of linear-to-bridged H-NS switching. Linear filaments able to inhibit only transcription initiation switch to bridged filaments able to inhibit both initiation and elongation using the same irregularly spaced DNA contacts.
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17
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Hu L, Guo S, Wang B, Fu R, Fan D, Jiang M, Fei Q, Gonzalez R. Bio-valorization of C1 gaseous substrates into bioalcohols: Potentials and challenges in reducing carbon emissions. Biotechnol Adv 2022; 59:107954. [DOI: 10.1016/j.biotechadv.2022.107954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 03/29/2022] [Accepted: 04/04/2022] [Indexed: 11/02/2022]
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18
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Prajapati P, Desai H, Chandarana C. Hand sanitizers as a preventive measure in COVID-19 pandemic, its characteristics, and harmful effects: a review. JOURNAL OF THE EGYPTIAN PUBLIC HEALTH ASSOCIATION 2022; 97:6. [PMID: 35133535 PMCID: PMC8823197 DOI: 10.1186/s42506-021-00094-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/28/2021] [Indexed: 01/06/2023]
Abstract
Abstract
Background
In the global health emergency caused by COVID-19, multiple experts have mandated the use of hand sanitizers as a safety measure from COVID-19. The sale of hand sanitizers has increased many folds. Therefore, when there is such large use of hand sanitizers, it becomes extremely important to study and understand hand sanitizers in a comprehensive manner.
Main body of the abstract
This article starts with the importance of sanitizers as a defence mechanism that is employed by the hand to fight against the coronavirus. This article provides information about history, types, composition, various dosage forms, and marketed formulations of hand sanitizers. The article sheds a detailed light on industrial production techniques for hand sanitizers and also outlines new innovative techniques that were employed by the industry to mass produce hand sanitizers in the wake of the pandemic. The article further dives into a comparison between hand sanitizers and soaps so as to give pros and cons of the use of soap against the use of hand sanitizers. One of the aims of the article is to study the side effects of sanitizers so as to develop a cautious approach while using hand sanitizers and therefore a comprehensive list of side effects of the use of hand sanitizers is given.
Conclusion
The review article finds that hand sanitizers are extremely efficient in fight the virus but along with it, it brings along arrange of risks which are outlined in the article.
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19
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Jayakody LN, Chinmoy B, Turner TL. Trends in valorization of highly-toxic lignocellulosic biomass derived-compounds via engineered microbes. BIORESOURCE TECHNOLOGY 2022; 346:126614. [PMID: 34954359 DOI: 10.1016/j.biortech.2021.126614] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 12/18/2021] [Accepted: 12/19/2021] [Indexed: 05/26/2023]
Abstract
Lignocellulosic biomass-derived fuels, chemicals, and materials are promising sustainable solutions to replace the current petroleum-based production. The direct microbial conversion of thermos-chemically pretreated lignocellulosic biomass is hampered by the presence of highly toxic chemical compounds. Also, thermo-catalytic upgrading of lignocellulosic biomass generates wastewater that contains heterogeneous toxic chemicals, a mixture of unutilized carbon. Metabolic engineering efforts have primarily focused on the conversion of carbohydrates in lignocellulose biomass; substantial opportunities exist to harness value from toxic lignocellulose-derived toxic compounds. This article presents the comprehensive metabolic routes and tolerance mechanisms to develop robust synthetic microbial cell factories to valorize the highly toxic compounds to advanced-platform chemicals. The obtained platform chemicals can be used to manufacture high-value biopolymers and biomaterials via a hybrid biochemical approach for replacing petroleum-based incumbents. The proposed strategy enables a sustainable bio-based materials economy by microbial biofunneling of lignocellulosic biomass-derived toxic molecules, an untapped biogenic carbon.
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Affiliation(s)
- Lahiru N Jayakody
- School of Biological Science, Southern Illinois University Carbondale, Carbondale, IL, USA; Fermentation Science Institute, Southern Illinois University Carbondale, Carbondale, IL, USA.
| | - Baroi Chinmoy
- Illinois Sustainable Technology Center, University of Illinois Urbana Champaign, IL, USA
| | - Timothy L Turner
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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Mora-Garduño JD, Tamayo-Nuñez J, Padilla-Vaca F, Ramírez-Montiel FB, Rangel-Serrano Á, Santos-Escobar F, Gutiérrez-Corona F, Páramo-Pérez I, Anaya-Velázquez F, García-Contreras R, Vargas-Maya NI, Franco B. Chromogenic Escherichia coli reporter strain for screening DNA damaging agents. AMB Express 2022; 12:2. [PMID: 34989906 PMCID: PMC8739417 DOI: 10.1186/s13568-021-01342-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 12/23/2021] [Indexed: 11/18/2022] Open
Abstract
The presence of pollutants in soil and water has given rise to diverse analytical and biological approaches to detect and measure contaminants in the environment. Using bacterial cells as reporter strains represents an advantage for detecting pollutants present in soil or water samples. Here, an Escherichia coli reporter strain expressing a chromoprotein capable of interacting with soil or water samples and responding to DNA damaging compounds is validated. The reporter strain generates a qualitative signal and is based on the expression of the coral chromoprotein AmilCP under the control of the recA promoter. This strain can be used simply by applying soil or water samples directly and rendering activation upon DNA damage. This reporter strain responds to agents that damage DNA (with an apparent detection limit of 1 µg of mitomycin C) without observable response to membrane integrity damage, protein folding or oxidative stress generating agents, in the latter case, DNA damage was observed. The developed reporter strain reported here is effective for the detection of DNA damaging agents present in soils samples. In a proof-of-concept analysis using soil containing chromium, showing activation at 15.56 mg/L of Cr(VI) present in soil and leached samples and is consistent with Cr(III) toxicity at high concentrations (130 µg). Our findings suggest that chromogenic reporter strains can be applied for simple screening, thus reducing the number of samples requiring analytical techniques.
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21
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Eom GE, Lee H, Kim S. Development of a genome-targeting mutator for the adaptive evolution of microbial cells. Nucleic Acids Res 2021; 50:e38. [PMID: 34928386 PMCID: PMC9023256 DOI: 10.1093/nar/gkab1244] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/05/2021] [Accepted: 12/03/2021] [Indexed: 11/30/2022] Open
Abstract
Methods that can randomly introduce mutations in the microbial genome have been used for classical genetic screening and, more recently, the evolutionary engineering of microbial cells. However, most methods rely on either cell-damaging agents or disruptive mutations of genes that are involved in accurate DNA replication, of which the latter requires prior knowledge of gene functions, and thus, is not easily transferable to other species. In this study, we developed a new mutator for in vivo mutagenesis that can directly modify the genomic DNA. Mutator protein, MutaEco, in which a DNA-modifying enzyme is fused to the α-subunit of Escherichia coli RNA polymerase, increases the mutation rate without compromising the cell viability and accelerates the adaptive evolution of E. coli for stress tolerance and utilization of unconventional carbon sources. This fusion strategy is expected to accommodate diverse DNA-modifying enzymes and may be easily adapted to various bacterial species.
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Affiliation(s)
- Ga-Eul Eom
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Hyunbin Lee
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Seokhee Kim
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
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22
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Fu GM, Deng MF, Chen Y, Chen YR, Wu SW, Lin P, Huang BJ, Liu CM, Wan Y. Analysis of microbial community, physiochemical indices, and volatile compounds of Chinese te-flavor baijiu daqu produced in different seasons. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2021; 101:6525-6532. [PMID: 34002396 DOI: 10.1002/jsfa.11324] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 01/17/2021] [Accepted: 05/17/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Chinese te-flavor baijiu (CTF), the most famous Chinese baijiu in Jiangxi province, China, is made from a unique daqu. Its characteristic style is closely related to the daqu used for fermentation. However, current studies on the effects of different production seasons on microbial communities, physicochemical indices, and volatile compounds in CTF daqu are very rare. RESULTS The relationships of microbial communities, physicochemical indices, and volatile compounds in CTF daqu produced in summer (July and August) and autumn (September and October) were studied. The results of Illumina MiSeq sequencing indicated that there was greater bacterial diversity in the CTF daqu-7 (produced in July) and CTF daqu-8 (produced in August) and greater fungal diversity in the CTF daqu-9 (produced in September) and CTF daqu-10 (produced in October). The physicochemical indices of CTF daqu produced in different seasons were significantly different. It was determined that CTF daqu-9 had the highest esterification and liquefaction abilities. A total of 44 volatile compounds, including alcohols, esters, aldehydes, and ketones were identified in CTF daqu produced during different seasons. Among them, CTF daqu-9 had the greatest alcohol content. CONCLUSION September (early autumn) is the best production period for CTF daqu. The results of the study provide a theoretical basis for the standardized and uniform production of Chinese baijiu. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Gui-Ming Fu
- State Key Laboratory of Food Science and Technology & College of food Science and Technology, Nanchang University, Nanchang, China
| | - Meng-Fei Deng
- State Key Laboratory of Food Science and Technology & College of food Science and Technology, Nanchang University, Nanchang, China
| | - Yan Chen
- State Key Laboratory of Food Science and Technology & College of food Science and Technology, Nanchang University, Nanchang, China
| | - Yan-Ru Chen
- State Key Laboratory of Food Science and Technology & College of food Science and Technology, Nanchang University, Nanchang, China
| | | | - Pei Lin
- Sitir Liquor Co., Ltd, Zhangshu, China
| | | | - Cheng-Mei Liu
- State Key Laboratory of Food Science and Technology & College of food Science and Technology, Nanchang University, Nanchang, China
| | - Yin Wan
- State Key Laboratory of Food Science and Technology & College of food Science and Technology, Nanchang University, Nanchang, China
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23
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Palo MZ, Zhu J, Mishanina TV, Landick R. Conserved Trigger Loop Histidine of RNA Polymerase II Functions as a Positional Catalyst Primarily through Steric Effects. Biochemistry 2021; 60:3323-3336. [PMID: 34705427 DOI: 10.1021/acs.biochem.1c00528] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In all domains of life, multisubunit RNA polymerases (RNAPs) catalyze both the extension of mRNA transcripts by nucleotide addition and the hydrolysis of RNA, which enables proofreading by removal of misincorporated nucleotides. A highly conserved catalytic module within RNAPs called the trigger loop (TL) functions as the key controller of these activities. The TL is proposed to act as a positional catalyst of phosphoryl transfer and transcript cleavage via electrostatic and steric contacts with substrates in its folded helical form. The function of a near-universally conserved TL histidine that contacts NTP phosphates is of particular interest. Despite its exceptional conservation, substitutions of the TL His with Gln support efficient catalysis in bacterial and yeast RNAPs. Unlike bacterial TLs, which contain a nearby Arg, the TL His is the only acid-base catalyst candidate in the eukaryotic RNAPII TL. Nonetheless, replacement of the TL His with Leu is reported to support cell growth in yeast, suggesting that even hydrogen bonding and polarity at this position may be dispensable for efficient catalysis by RNAPII. To test how a TL His-to-Leu substitution affects the enzymatic functions of RNAPII, we compared its rates of nucleotide addition, pyrophosphorolysis, and RNA hydrolysis to those of the wild-type RNAPII enzyme. The His-to-Leu substitution slightly reduced rates of phosphoryl transfer with little if any effect on intrinsic transcript cleavage. These findings indicate that the highly conserved TL His is neither an obligate acid-base catalyst nor a polar contact for NTP phosphates but instead functions as a positional catalyst mainly through steric effects.
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Affiliation(s)
- Michael Z Palo
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Junqiao Zhu
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Tatiana V Mishanina
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.,Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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24
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Matson MM, Cepeda MM, Zhang A, Case AE, Kavvas ES, Wang X, Carroll AL, Tagkopoulos I, Atsumi S. Adaptive laboratory evolution for improved tolerance of isobutyl acetate in Escherichia coli. Metab Eng 2021; 69:50-58. [PMID: 34763090 DOI: 10.1016/j.ymben.2021.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 10/14/2021] [Accepted: 11/04/2021] [Indexed: 02/08/2023]
Abstract
Previously, Escherichia coli was engineered to produce isobutyl acetate (IBA). Titers greater than the toxicity threshold (3 g/L) were achieved by using layer-assisted production. To avoid this costly and complex method, adaptive laboratory evolution (ALE) was applied to E. coli for improved IBA tolerance. Over 37 rounds of selective pressure, 22 IBA-tolerant mutants were isolated. Remarkably, these mutants not only tolerate high IBA concentrations, they also produce higher IBA titers. Using whole-genome sequencing followed by CRISPR/Cas9 mediated genome editing, the mutations (SNPs in metH, rho and deletion of arcA) that confer improved tolerance and higher titers were elucidated. The improved IBA titers in the evolved mutants were a result of an increased supply of acetyl-CoA and altered transcriptional machinery. Without the use of phase separation, a strain capable of 3.2-fold greater IBA production than the parent strain was constructed by combing select beneficial mutations. These results highlight the impact improved tolerance has on the production capability of a biosynthetic system.
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Affiliation(s)
- Morgan M Matson
- Department of Chemistry, University of California, Davis, CA, 95616, USA
| | - Mateo M Cepeda
- Department of Chemistry, University of California, Davis, CA, 95616, USA
| | - Angela Zhang
- Department of Chemistry, University of California, Davis, CA, 95616, USA
| | - Anna E Case
- Department of Chemistry, University of California, Davis, CA, 95616, USA
| | - Erol S Kavvas
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Xiaokang Wang
- Genome Center, University of California, Davis, CA, 95616, USA; Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - Austin L Carroll
- Department of Chemistry, University of California, Davis, CA, 95616, USA
| | - Ilias Tagkopoulos
- Genome Center, University of California, Davis, CA, 95616, USA; Department of Computer Science, University of California, Davis, CA, 95616, USA
| | - Shota Atsumi
- Department of Chemistry, University of California, Davis, CA, 95616, USA.
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25
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Milani ES, Hasani A, Varschochi M, Sadeghi J, Memar MY, Hasani A. Biocide resistance in Acinetobacter baumannii: appraising the mechanisms. J Hosp Infect 2021; 117:135-146. [PMID: 34560167 DOI: 10.1016/j.jhin.2021.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 11/17/2022]
Abstract
A global upsurge in antibiotic-resistant Acinetobacter baumannii requires supervised selection of biocides and disinfectants to avert nosocomial infections by reducing its spread. Moreover, inadequate and improper biocides have been reported as a contributing factor in antimicrobial resistance. Regardless of the manner of administration, a biocidal concentration that does not kill the target bacteria creates a stress response, propagating the resistance mechanisms. This is an essential aspect of the disinfection programme and the overall bio-contamination management plan. Knowing the mechanisms of action of biocides and resistance modalities may open new avenues to discover novel agents. This review describes the mechanisms of action of some biocides, resistance mechanisms, and approaches to study susceptibility/resistance to these agents.
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Affiliation(s)
- E S Milani
- Infectious and Tropical Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - A Hasani
- Infectious and Tropical Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Clinical Research Development Unit, Sina Educational, Research and Treatment Centre, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - M Varschochi
- Infectious and Tropical Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
| | - J Sadeghi
- Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - M Y Memar
- Infectious and Tropical Diseases Research Centre, Tabriz University of Medical Sciences, Tabriz, Iran
| | - A Hasani
- Department of Clinical Biochemistry and Laboratory Sciences, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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26
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Costa P, Usai G, Re A, Manfredi M, Mannino G, Bertea CM, Pessione E, Mazzoli R. Clostridium cellulovorans Proteomic Responses to Butanol Stress. Front Microbiol 2021; 12:674639. [PMID: 34367082 PMCID: PMC8336468 DOI: 10.3389/fmicb.2021.674639] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 06/14/2021] [Indexed: 12/16/2022] Open
Abstract
Combination of butanol-hyperproducing and hypertolerant phenotypes is essential for developing microbial strains suitable for industrial production of bio-butanol, one of the most promising liquid biofuels. Clostridium cellulovorans is among the microbial strains with the highest potential for direct production of n-butanol from lignocellulosic wastes, a process that would significantly reduce the cost of bio-butanol. However, butanol exhibits higher toxicity compared to ethanol and C. cellulovorans tolerance to this solvent is low. In the present investigation, comparative gel-free proteomics was used to study the response of C. cellulovorans to butanol challenge and understand the tolerance mechanisms activated in this condition. Sequential Window Acquisition of all Theoretical fragment ion spectra Mass Spectrometry (SWATH-MS) analysis allowed identification and quantification of differentially expressed soluble proteins. The study data are available via ProteomeXchange with the identifier PXD024183. The most important response concerned modulation of protein biosynthesis, folding and degradation. Coherent with previous studies on other bacteria, several heat shock proteins (HSPs), involved in protein quality control, were up-regulated such as the chaperones GroES (Cpn10), Hsp90, and DnaJ. Globally, our data indicate that protein biosynthesis is reduced, likely not to overload HSPs. Several additional metabolic adaptations were triggered by butanol exposure such as the up-regulation of V- and F-type ATPases (involved in ATP synthesis/generation of proton motive force), enzymes involved in amino acid (e.g., arginine, lysine, methionine, and branched chain amino acids) biosynthesis and proteins involved in cell envelope re-arrangement (e.g., the products of Clocel_4136, Clocel_4137, Clocel_4144, Clocel_4162 and Clocel_4352, involved in the biosynthesis of saturated fatty acids) and a redistribution of carbon flux through fermentative pathways (acetate and formate yields were increased and decreased, respectively). Based on these experimental findings, several potential gene targets for metabolic engineering strategies aimed at improving butanol tolerance in C. cellulovorans are suggested. This includes overexpression of HSPs (e.g., GroES, Hsp90, DnaJ, ClpC), RNA chaperone Hfq, V- and F-type ATPases and a number of genes whose function in C. cellulovorans is currently unknown.
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Affiliation(s)
- Paolo Costa
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Giulia Usai
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy.,Centre for Sustainable Future Technologies, Fondazione Istituto Italiano di Tecnologia, Turin, Italy.,Department of Applied Science and Technology, Politecnico di Torino, Turin, Italy
| | - Angela Re
- Centre for Sustainable Future Technologies, Fondazione Istituto Italiano di Tecnologia, Turin, Italy
| | - Marcello Manfredi
- Center for Translational Research on Autoimmune and Allergic Diseases, Università del Piemonte Orientale, Novara, Italy.,Department of Translational Medicine, Università del Piemonte Orientale, Novara, Italy
| | - Giuseppe Mannino
- Plant Physiology Unit, Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Cinzia Margherita Bertea
- Plant Physiology Unit, Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Enrica Pessione
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Roberto Mazzoli
- Structural and Functional Biochemistry, Laboratory of Proteomics and Metabolic Engineering of Prokaryotes, Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
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27
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Hans M, Lugani Y, Chandel AK, Rai R, Kumar S. Production of first- and second-generation ethanol for use in alcohol-based hand sanitizers and disinfectants in India. BIOMASS CONVERSION AND BIOREFINERY 2021; 13:1-18. [PMID: 34075327 PMCID: PMC8155184 DOI: 10.1007/s13399-021-01553-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 06/12/2023]
Abstract
Emergence of "severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)" causing "COVID-19" or "coronavirus disease 19" as pandemic has got worldwide attention towards hygiene as the first line of defense for the infection control. It is first line of defense not only from COVID-19 but also from other infectious diseases caused by deadly pathogens such as cholera, hepatitis, tuberculosis, polio, etc. Absence of any particular vaccine or treatment let World Health Organization (WHO) recommend to the public to maintain social distancing along with regularly washing their hands with soap, sanitize their hands (where washing is not possible), and disinfect their belongings and buildings to avoid the infection. Out of various formulations available in the market, WHO has recommended alcohol-based hand sanitizers, which mainly comprise of ethanol, isopropyl alcohols, and hydrogen peroxides in different combinations due to their high potential to kill the broad range of pathogens including bacterial, viral, fungal, helminthes, etc. Therefore, alcohol-based sanitizers are in high demand since centuries to prevent infection from pathogenic diseases. Ethanol is the most common and popular alcohol in terms of vanishing wide range of pathogens, convenient to use and its production. Ethanol is produced worldwide and is used in various sectors, e.g., beauty and cosmetics, food and beverages, and as the most demanding gasoline additive. The present review is focused on the ethanol production in India, its diversified applications emphasizing hand sanitizers with discussions on formulation of sanitizer and disinfectants, and viability of lignocellulosic and food grain-based ethanol. The review article also emphasizes on the technological details of 1G and 2G ethanol production, their associated challenges, and inputs for the improved ethanol yields so as to strengthen the supply chain of ethanol in India, and making "Atmanirbhar Bharat" (Self-reliant India) campaign of Indian government successfully viable.
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Affiliation(s)
- Meenu Hans
- Biochemical Conversion Division, Sardar Swaran Singh National Institute of Bio-Energy, Jalandhar-Kapurthala Road, Wadala Kalan, Kapurthala, Punjab 144601 India
- Department of Microbiology, Guru Nanak Dev University, Amritsar, Punjab 143005 India
| | - Yogita Lugani
- Department of Agriculture and Environmental Sciences, National Institute of Food Technology Entrepreneurship and Management (NIFTEM), Sonepat, Haryana 131028 India
| | - Anuj K. Chandel
- Department of Biotechnology, Engineering School of Lorena (EEL), University of São Paulo, Lorena, SP Brazil
| | - Rohit Rai
- Faculty of Applied Medical Sciences, Lovely Professional University, Phagwara, Punjab 144411 India
| | - Sachin Kumar
- Biochemical Conversion Division, Sardar Swaran Singh National Institute of Bio-Energy, Jalandhar-Kapurthala Road, Wadala Kalan, Kapurthala, Punjab 144601 India
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28
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Shiver AL, Osadnik H, Peters JM, Mooney RA, Wu PI, Henry KK, Braberg H, Krogan NJ, Hu JC, Landick R, Huang KC, Gross CA. Chemical-genetic interrogation of RNA polymerase mutants reveals structure-function relationships and physiological tradeoffs. Mol Cell 2021; 81:2201-2215.e9. [PMID: 34019789 PMCID: PMC8484514 DOI: 10.1016/j.molcel.2021.04.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 01/25/2021] [Accepted: 04/29/2021] [Indexed: 11/16/2022]
Abstract
The multi-subunit bacterial RNA polymerase (RNAP) and its associated regulators carry out transcription and integrate myriad regulatory signals. Numerous studies have interrogated RNAP mechanism, and RNAP mutations drive Escherichia coli adaptation to many health- and industry-relevant environments, yet a paucity of systematic analyses hampers our understanding of the fitness trade-offs from altering RNAP function. Here, we conduct a chemical-genetic analysis of a library of RNAP mutants. We discover phenotypes for non-essential insertions, show that clustering mutant phenotypes increases their predictive power for drawing functional inferences, and demonstrate that some RNA polymerase mutants both decrease average cell length and prevent killing by cell-wall targeting antibiotics. Our findings demonstrate that RNAP chemical-genetic interactions provide a general platform for interrogating structure-function relationships in vivo and for identifying physiological trade-offs of mutations, including those relevant for disease and biotechnology. This strategy should have broad utility for illuminating the role of other important protein complexes.
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Affiliation(s)
- Anthony L Shiver
- Graduate Group in Biophysics, University of California San Francisco, San Francisco, CA 94158, USA; Department of Bioengineering, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hendrik Osadnik
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Jason M Peters
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Rachel A Mooney
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Peter I Wu
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Kemardo K Henry
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Hannes Braberg
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, University of California San Francisco, San Francisco, CA 94158, USA
| | - Nevan J Krogan
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA; Quantitative Biosciences Institute, University of California San Francisco, San Francisco, CA 94158, USA; Gladstone Institutes, San Francisco, CA 94158, USA; Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - James C Hu
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
| | - Carol A Gross
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94158, USA; Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA 94158, USA; California Institute of Quantitative Biology, University of California San Francisco, San Francisco, CA 94158, USA.
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29
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Bennett RK, Gregory GJ, Gonzalez JE, Har JRG, Antoniewicz MR, Papoutsakis ET. Improving the Methanol Tolerance of an Escherichia coli Methylotroph via Adaptive Laboratory Evolution Enhances Synthetic Methanol Utilization. Front Microbiol 2021; 12:638426. [PMID: 33643274 PMCID: PMC7904680 DOI: 10.3389/fmicb.2021.638426] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 01/21/2021] [Indexed: 02/05/2023] Open
Abstract
There is great interest in developing synthetic methylotrophs that harbor methane and methanol utilization pathways in heterologous hosts such as Escherichia coli for industrial bioconversion of one-carbon compounds. While there are recent reports that describe the successful engineering of synthetic methylotrophs, additional efforts are required to achieve the robust methylotrophic phenotypes required for industrial realization. Here, we address an important issue of synthetic methylotrophy in E. coli: methanol toxicity. Both methanol, and its oxidation product, formaldehyde, are cytotoxic to cells. Methanol alters the fluidity and biological properties of cellular membranes while formaldehyde reacts readily with proteins and nucleic acids. Thus, efforts to enhance the methanol tolerance of synthetic methylotrophs are important. Here, adaptive laboratory evolution was performed to improve the methanol tolerance of several E. coli strains, both methylotrophic and non-methylotrophic. Serial batch passaging in rich medium containing toxic methanol concentrations yielded clones exhibiting improved methanol tolerance. In several cases, these evolved clones exhibited a > 50% improvement in growth rate and biomass yield in the presence of high methanol concentrations compared to the respective parental strains. Importantly, one evolved clone exhibited a two to threefold improvement in the methanol utilization phenotype, as determined via 13C-labeling, at non-toxic, industrially relevant methanol concentrations compared to the respective parental strain. Whole genome sequencing was performed to identify causative mutations contributing to methanol tolerance. Common mutations were identified in 30S ribosomal subunit proteins, which increased translational accuracy and provided insight into a novel methanol tolerance mechanism. This study addresses an important issue of synthetic methylotrophy in E. coli and provides insight as to how methanol toxicity can be alleviated via enhancing methanol tolerance. Coupled improvement of methanol tolerance and synthetic methanol utilization is an important advancement for the field of synthetic methylotrophy.
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Affiliation(s)
- R Kyle Bennett
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, United States.,Molecular Biotechnology Laboratory, The Delaware Biotechnology Institute, University of Delaware, Newark, DE, United States
| | - Gwendolyn J Gregory
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, United States.,Molecular Biotechnology Laboratory, The Delaware Biotechnology Institute, University of Delaware, Newark, DE, United States
| | - Jacqueline E Gonzalez
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, United States
| | - Jie Ren Gerald Har
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, United States
| | - Maciek R Antoniewicz
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, United States
| | - Eleftherios T Papoutsakis
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, United States.,Molecular Biotechnology Laboratory, The Delaware Biotechnology Institute, University of Delaware, Newark, DE, United States
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30
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Kinnersley M, Schwartz K, Yang DD, Sherlock G, Rosenzweig F. Evolutionary dynamics and structural consequences of de novo beneficial mutations and mutant lineages arising in a constant environment. BMC Biol 2021; 19:20. [PMID: 33541358 PMCID: PMC7863352 DOI: 10.1186/s12915-021-00954-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 01/08/2021] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Microbial evolution experiments can be used to study the tempo and dynamics of evolutionary change in asexual populations, founded from single clones and growing into large populations with multiple clonal lineages. High-throughput sequencing can be used to catalog de novo mutations as potential targets of selection, determine in which lineages they arise, and track the fates of those lineages. Here, we describe a long-term experimental evolution study to identify targets of selection and to determine when, where, and how often those targets are hit. RESULTS We experimentally evolved replicate Escherichia coli populations that originated from a mutator/nonsense suppressor ancestor under glucose limitation for between 300 and 500 generations. Whole-genome, whole-population sequencing enabled us to catalog 3346 de novo mutations that reached > 1% frequency. We sequenced the genomes of 96 clones from each population when allelic diversity was greatest in order to establish whether mutations were in the same or different lineages and to depict lineage dynamics. Operon-specific mutations that enhance glucose uptake were the first to rise to high frequency, followed by global regulatory mutations. Mutations related to energy conservation, membrane biogenesis, and mitigating the impact of nonsense mutations, both ancestral and derived, arose later. New alleles were confined to relatively few loci, with many instances of identical mutations arising independently in multiple lineages, among and within replicate populations. However, most never exceeded 10% in frequency and were at a lower frequency at the end of the experiment than at their maxima, indicating clonal interference. Many alleles mapped to key structures within the proteins that they mutated, providing insight into their functional consequences. CONCLUSIONS Overall, we find that when mutational input is increased by an ancestral defect in DNA repair, the spectrum of high-frequency beneficial mutations in a simple, constant resource-limited environment is narrow, resulting in extreme parallelism where many adaptive mutations arise but few ever go to fixation.
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Affiliation(s)
- Margie Kinnersley
- Division of Biological Sciences, The University of Montana, Missoula, MT, 59812, USA
| | - Katja Schwartz
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305-5120, USA
| | - Dong-Dong Yang
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Gavin Sherlock
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305-5120, USA.
| | - Frank Rosenzweig
- Division of Biological Sciences, The University of Montana, Missoula, MT, 59812, USA.
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
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31
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Schalck T, den Bergh BV, Michiels J. Increasing Solvent Tolerance to Improve Microbial Production of Alcohols, Terpenoids and Aromatics. Microorganisms 2021; 9:249. [PMID: 33530454 PMCID: PMC7912173 DOI: 10.3390/microorganisms9020249] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/14/2021] [Accepted: 01/20/2021] [Indexed: 12/16/2022] Open
Abstract
Fuels and polymer precursors are widely used in daily life and in many industrial processes. Although these compounds are mainly derived from petrol, bacteria and yeast can produce them in an environment-friendly way. However, these molecules exhibit toxic solvent properties and reduce cell viability of the microbial producer which inevitably impedes high product titers. Hence, studying how product accumulation affects microbes and understanding how microbial adaptive responses counteract these harmful defects helps to maximize yields. Here, we specifically focus on the mode of toxicity of industry-relevant alcohols, terpenoids and aromatics and the associated stress-response mechanisms, encountered in several relevant bacterial and yeast producers. In practice, integrating heterologous defense mechanisms, overexpressing native stress responses or triggering multiple protection pathways by modifying the transcription machinery or small RNAs (sRNAs) are suitable strategies to improve solvent tolerance. Therefore, tolerance engineering, in combination with metabolic pathway optimization, shows high potential in developing superior microbial producers.
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Affiliation(s)
- Thomas Schalck
- VIB Center for Microbiology, Flanders Institute for Biotechnology, B-3001 Leuven, Belgium; (T.S.); (B.V.d.B.)
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium
| | - Bram Van den Bergh
- VIB Center for Microbiology, Flanders Institute for Biotechnology, B-3001 Leuven, Belgium; (T.S.); (B.V.d.B.)
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium
| | - Jan Michiels
- VIB Center for Microbiology, Flanders Institute for Biotechnology, B-3001 Leuven, Belgium; (T.S.); (B.V.d.B.)
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium
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32
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Morante J, Quispe AM, Ymaña B, Moya-Salazar J, Luque N, Soza G, Ramos Chirinos M, Pons MJ. Tolerance to disinfectants (chlorhexidine and isopropanol) and its association with antibiotic resistance in clinically-related Klebsiella pneumoniae isolates. Pathog Glob Health 2021; 115:53-60. [PMID: 33455564 DOI: 10.1080/20477724.2020.1845479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Disinfectants play an essential role in controlling the dissemination of bacteria in health care settings, but it may also contribute to the selection of antibiotic resistance bacteria. This study looked at Klebsiella pneumoniae isolates collected from three hospitals in Lima, Peru, in order to evaluate: their susceptibility to chlorhexidine [CHG] and isopropanol [ISP]), and their association with antimicrobial susceptibility. We analyzed 59 K. pneumoniae isolates and assessed their CHG and ISP susceptibility by minimum inhibitory concentrations (MICs). Additionally, we performed a regression analysis to assess the association between disinfectant tolerance and antibiotic resistance (measured by the disc diffusion method), colistin resistance (by microdilution), carbapenemases presence (by polymerase chain reaction [PCR]), and clonal relationships (by pulsed-field gel electrophoresis [PFGE]). Eleven K. pneumoniae strains were isolated from fomites, and 48 strains from clinical samples. The MIC range of these isolates was 8-128 µg/ml for CHG and 16-256 mg/ml for ISP. We found that resistance to trimethoprim/sulfamethoxazole (TMP/SMX) was the main factor associated with CHG log2 MIC (ß = 0.65; 95%CI: 0.03, 1.27; R2 = 0.07). In the case of ISP, the log2(MIC) was associated with the institution of origin, showing lower ISP log2(MIC) in fomites compared to clinical samples(ß = -0.77; 95%CI: -1.54, -0.01; R2 = 0.08). Resistance to CHG and ISP among K. pneumoniae isolates found in Peruvian hospitals seems to be elevated and highly variable. Further studies are needed to confirm our results and implement actionable interventions if necessary.
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Affiliation(s)
- Jasmine Morante
- Escuela de Medicina, Universidad Científica del Sur , Lima, Peru
| | | | - Barbara Ymaña
- Escuela de Medicina, Universidad Científica del Sur , Lima, Peru
| | - Jeel Moya-Salazar
- Hospital Nacional Docente Madre Niño San Bartolomé , Lima, Peru.,Escuela de Posgrado, Universidad Privada San Juan Bautista , Lima, Peru
| | - Néstor Luque
- Médico asistente de UCI. Hospital Nacional Dos de Mayo , Lima, Peru.,Escuela de Medicina Humana. Facultad de Ciencias de la Salud, Universidad Peruana Unión , Lima, Peru
| | | | | | - Maria J Pons
- Escuela de Medicina, Universidad Científica del Sur , Lima, Peru
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33
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Oh E. Monitoring Bacterial Translation Rates Genome-Wide. Methods Mol Biol 2021; 2252:3-26. [PMID: 33765269 DOI: 10.1007/978-1-0716-1150-0_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Modern DNA sequencing technologies have allowed for the sequencing of tens of thousands of bacterial genomes. While this explosion of information has brought about new insights into the diversity of the prokaryotic world, much less is known of the identity of proteins encoded within these genomes, as well as their rates of production. The advent of ribosome profiling, or the deep sequencing of ribosome-protected footprints, has recently enabled the systematic evaluation of every protein-coding region in a given experimental condition, the rates of protein production for each gene, and the variability in translation rates across each message. Here, I provide an update to the bacterial ribosome profiling approach, with a particular emphasis on a simplified strategy to reduce cloning time.
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Affiliation(s)
- Eugene Oh
- Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA, USA.
- Department of Medicine, Harvard Medical School, Boston, MA, USA.
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34
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Connolly JPR, Roe AJ, O'Boyle N. Prokaryotic life finds a way: insights from evolutionary experimentation in bacteria. Crit Rev Microbiol 2020; 47:126-140. [PMID: 33332206 DOI: 10.1080/1040841x.2020.1854172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
While evolution proceeds through the generation of random variant alleles, the application of selective pressures can select for subsets of mutations that confer fitness-improving physiological benefits. This, in essence, defines the process of adaptive evolution. The rapid replication rate of bacteria has allowed for the design of experiments to study these processes over a reasonable timeframe within a laboratory setting. This has been greatly assisted by advances in tractability of diverse microorganisms, next generation sequencing technologies and bioinformatic analysis pipelines. Examining the processes by which organisms adapt their genetic code to cope with sub-optimal growth conditions has yielded a wealth of molecular insight into diverse biological processes. Here we discuss how the study of adaptive evolutionary trajectories in bacteria has allowed for improved understanding of stress responses, revealed important insight into microbial physiology, allowed for the production of highly optimised strains for use in biotechnology and increased our knowledge of the role of genomic plasticity in chronic infections.
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Affiliation(s)
- James P R Connolly
- Newcastle University Biosciences Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Andrew J Roe
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Nicky O'Boyle
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
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Golin AP, Choi D, Ghahary A. Hand sanitizers: A review of ingredients, mechanisms of action, modes of delivery, and efficacy against coronaviruses. Am J Infect Control 2020; 48:1062-1067. [PMID: 32565272 PMCID: PMC7301780 DOI: 10.1016/j.ajic.2020.06.182] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/14/2020] [Accepted: 06/15/2020] [Indexed: 12/13/2022]
Abstract
Background The emergence of the novel virus, SARS-CoV-2, has posed unprecedented challenges to public health around the world. Currently, strategies to deal with COVID-19 are purely supportive and preventative, aimed at reducing transmission. An effective and simple method for reducing transmission of infections in public or healthcare settings is hand hygiene. Unfortunately, little is known regarding the efficacy of hand sanitizers against SARS-CoV-2. Methods In this review, an extensive literature search was performed to succinctly summarize the primary active ingredients and mechanisms of action of hand sanitizers, compare the effectiveness and compliance of gel and foam sanitizers, and predict whether alcohol and non-alcohol hand sanitizers would be effective against SARS-CoV-2. Results Most alcohol-based hand sanitizers are effective at inactivating enveloped viruses, including coronaviruses. With what is currently known in the literature, one may not confidently suggest one mode of hand sanitizing delivery over the other. When hand washing with soap and water is unavailable, a sufficient volume of sanitizer is necessary to ensure complete hand coverage, and compliance is critical for appropriate hand hygiene. Conclusions By extrapolating effectiveness of hand sanitizers on viruses of similar structure to SARS-CoV-2, this virus should be effectively inactivated with current hand hygiene products, though future research should attempt to determine this directly.
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Yang J, Kim HE, Jung YH, Kim J, Kim DH, Walmsley AR, Kim KH. Zmo0994, a novel LEA-like protein from Zymomonas mobilis, increases multi-abiotic stress tolerance in Escherichia coli. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:151. [PMID: 32863881 PMCID: PMC7448490 DOI: 10.1186/s13068-020-01790-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 08/16/2020] [Indexed: 05/25/2023]
Abstract
BACKGROUND Pretreatment processes and subsequent enzymatic hydrolysis are prerequisites to utilize lignocellulosic sugar for fermentation. However, the resulting hydrolysate frequently hinders fermentation processes due to the presence of inhibitors and toxic products (e.g., ethanol). Thus, it is crucial to develop robust microbes conferring multi-stress tolerance. RESULTS Zmo0994, a functionally uncharacterized protein from Zymomonas mobilis, was identified and characterized for the first time. A major effect of Zmo0994 was a significant enhancement in the tolerance to abiotic stresses such as ethanol, furfural, 5'-hydroxymethylfurfural and high temperature, when expressed in Escherichia coli. Through transcriptome analysis and in vivo experiments, the cellular mechanism of this protein was revealed as due to its ability to trigger genes, involved in aerobic respiration for ATP synthesis. CONCLUSIONS These findings have significant implications that might lead to the development of robust microbes for the highly efficient industrial fermentation processes.
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Affiliation(s)
- Jungwoo Yang
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841 Republic of Korea
| | - Ha Eun Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841 Republic of Korea
| | - Young Hoon Jung
- School of Food Science and Biotechnology, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu, 41566 Republic of Korea
| | - Jungyeon Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841 Republic of Korea
| | - Do Hyoung Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841 Republic of Korea
| | - Adrian R. Walmsley
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE UK
| | - Kyoung Heon Kim
- Department of Biotechnology, Graduate School, Korea University, Seoul, 02841 Republic of Korea
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Genome-Scale Transcription-Translation Mapping Reveals Features of Zymomonas mobilis Transcription Units and Promoters. mSystems 2020; 5:5/4/e00250-20. [PMID: 32694125 PMCID: PMC7566282 DOI: 10.1128/msystems.00250-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Efforts to rationally engineer synthetic pathways in Zymomonas mobilis are impeded by a lack of knowledge and tools for predictable and quantitative programming of gene regulation at the transcriptional, posttranscriptional, and posttranslational levels. With the detailed functional characterization of the Z. mobilis genome presented in this work, we provide crucial knowledge for the development of synthetic genetic parts tailored to Z. mobilis. This information is vital as researchers continue to develop Z. mobilis for synthetic biology applications. Our methods and statistical analyses also provide ways to rapidly advance the understanding of poorly characterized bacteria via empirical data that enable the experimental validation of sequence-based prediction for genome characterization and annotation. Zymomonas mobilis is an ethanologenic alphaproteobacterium with promise for the industrial conversion of renewable plant biomass into fuels and chemical bioproducts. Limited functional annotation of the Z. mobilis genome is a current barrier to both fundamental studies of Z. mobilis and its development as a synthetic biology chassis. To gain insight, we collected sample-matched multiomics data, including RNA sequencing (RNA-seq), transcription start site (TSS) sequencing (TSS-seq), termination sequencing (term-seq), ribosome profiling, and label-free shotgun proteomic mass spectrometry, across different growth conditions and used these data to improve annotation and assign functional sites in the Z. mobilis genome. Proteomics and ribosome profiling informed revisions of protein-coding genes, which included 44 start codon changes and 42 added proteins. We developed statistical methods for annotating transcript 5′ and 3′ ends, enabling the identification of 3,940 TSSs and their corresponding promoters and 2,091 transcription termination sites, which were distinguished from RNA processing sites by the lack of an adjacent RNA 5′ end. Our results revealed that Z. mobilis σA −35 and −10 promoter elements closely resemble canonical Escherichia coli −35 and −10 elements, with one notable exception: the Z. mobilis −10 element lacks the highly conserved −7 thymine observed in E. coli and other previously characterized σA promoters. The σA promoters of another alphaproteobacterium, Caulobacter crescentus, similarly lack the conservation of −7 thymine in their −10 elements. Our results anchor the development of Z. mobilis as a platform for synthetic biology and establish strategies for empirical genome annotation that can complement purely computational methods. IMPORTANCE Efforts to rationally engineer synthetic pathways in Zymomonas mobilis are impeded by a lack of knowledge and tools for predictable and quantitative programming of gene regulation at the transcriptional, posttranscriptional, and posttranslational levels. With the detailed functional characterization of the Z. mobilis genome presented in this work, we provide crucial knowledge for the development of synthetic genetic parts tailored to Z. mobilis. This information is vital as researchers continue to develop Z. mobilis for synthetic biology applications. Our methods and statistical analyses also provide ways to rapidly advance the understanding of poorly characterized bacteria via empirical data that enable the experimental validation of sequence-based prediction for genome characterization and annotation.
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Genomics and transcriptomics analysis reveals the mechanism of isobutanol tolerance of a laboratory evolved Lactococcus lactis strain. Sci Rep 2020; 10:10850. [PMID: 32616741 PMCID: PMC7331579 DOI: 10.1038/s41598-020-67635-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 06/05/2020] [Indexed: 01/09/2023] Open
Abstract
Isobutanol, in spite of its significant superiority over ethanol as a biofuel, remains commercially non-viable due to the non-availability of a suitable chassis which can handle the solvent toxicity associated with its production. To meet this challenge, we chose Lactococcus lactis which is known for its ability to handle environmental stress and carried out Adaptive laboratory evolution (ALE) in a continuous stirred tank reactor (CSTR) to evolve an isobutanol tolerant strain. The strain was grown for more than 60 days (> 250 generations) while gradually increasing the selection pressure, i.e. isobutanol concentration, in the feed. This led to the evolution of a strain that had an exceptionally high tolerance of up to 40 g/l of isobutanol even though a scanning electron microscope (SEM) study as well as analysis of membrane potential revealed only minor changes in cellular morphology. Whole genome sequencing which was done to confirm the strain integrity also showed comparatively few mutations in the evolved strain. However, the criticality of these mutations was reflected in major changes that occurred in the transcriptome, where gene expression levels from a wide range of categories that involved membrane transport, amino acid metabolism, sugar uptake and cell wall synthesis were significantly altered. Analysing the synergistic effect of these changes that lead to the complex phenotype of isobutanol tolerance can help in the construction of better host platforms for isobutanol production.
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Kay JE, Jewett MC. A cell-free system for production of 2,3-butanediol is robust to growth-toxic compounds. Metab Eng Commun 2020; 10:e00114. [PMID: 31934547 PMCID: PMC6951449 DOI: 10.1016/j.mec.2019.e00114] [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: 08/03/2019] [Revised: 11/14/2019] [Accepted: 11/19/2019] [Indexed: 11/23/2022] Open
Abstract
The need for sustainable, low-cost production of bioenergy and commodity chemicals is increasing. Unfortunately, the engineering potential of whole-cell catalysts to address this need can be hampered by cellular toxicity. When such bottlenecks limit the commercial feasibility of whole-cell fermentation, cell-free, or in vitro, based approaches may offer an alternative. Here, we assess the impact of three classes of growth toxic compounds on crude extract-based, cell-free chemical conversions. As a model system, we test a metabolic pathway for conversion of glucose to 2,3-butanediol (2,3-BDO) in lysates of Escherichia coli. First, we characterized 2,3-BDO production with different classes of antibiotics and found, as expected, that the system is uninhibited by compounds that prevent cell growth by means of cell wall replication and DNA, RNA, and protein synthesis. Second, we considered the impact of polar solvent addition (e.g., methanol, n-butanol). We observed that volumetric productivities (g/L/h) were slowed with increasing hydrophobicity of added alcohols. Finally, we investigated the effects of using pretreated biomass hydrolysate as a feed stock, observing a 25% reduction in 2,3-BDO production as a result of coumaroyl and feruloyl amides. Overall, we find the cell-free system to be robust to working concentrations of antibiotics and other compounds that are toxic to cell growth, but do not denature or inhibit relevant enzymes.
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Affiliation(s)
- Jennifer E. Kay
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
| | - Michael C. Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, 60208, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, 60208, USA
- Robert H. Lurie Comprehensive Cancer Center and Northwestern University, Chicago, IL, 60611, USA
- Simpson Querrey Institute, Northwestern University, Chicago, IL, 60611, USA
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Michel AM, Kiniry SJ, O'Connor PBF, Mullan JP, Baranov PV. GWIPS-viz: 2018 update. Nucleic Acids Res 2019; 46:D823-D830. [PMID: 28977460 PMCID: PMC5753223 DOI: 10.1093/nar/gkx790] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 08/29/2017] [Indexed: 12/15/2022] Open
Abstract
The GWIPS-viz browser (http://gwips.ucc.ie/) is an on-line genome browser which is tailored for exploring ribosome profiling (Ribo-seq) data. Since its publication in 2014, GWIPS-viz provides Ribo-seq data for an additional 14 genomes bringing the current total to 23. The integration of new Ribo-seq data has been automated thereby increasing the number of available tracks to 1792, a 10-fold increase in the last three years. The increase is particularly substantial for data derived from human sources. Following user requests, we added the functionality to download these tracks in bigWig format. We also incorporated new types of data (e.g. TCP-seq) as well as auxiliary tracks from other sources that help with the interpretation of Ribo-seq data. Improvements in the visualization of the data have been carried out particularly for bacterial genomes where the Ribo-seq data are now shown in a strand specific manner. For higher eukaryotic datasets, we provide characteristics of individual datasets using the RUST program which includes the triplet periodicity, sequencing biases and relative inferred A-site dwell times. This information can be used for assessing the quality of Ribo-seq datasets. To improve the power of the signal, we aggregate Ribo-seq data from several studies into Global aggregate tracks for each genome.
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Affiliation(s)
- Audrey M Michel
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Stephen J Kiniry
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | | | - James P Mullan
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
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Sandberg TE, Salazar MJ, Weng LL, Palsson BO, Feist AM. The emergence of adaptive laboratory evolution as an efficient tool for biological discovery and industrial biotechnology. Metab Eng 2019; 56:1-16. [PMID: 31401242 DOI: 10.1016/j.ymben.2019.08.004] [Citation(s) in RCA: 254] [Impact Index Per Article: 50.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 08/01/2019] [Accepted: 08/05/2019] [Indexed: 12/21/2022]
Abstract
Harnessing the process of natural selection to obtain and understand new microbial phenotypes has become increasingly possible due to advances in culturing techniques, DNA sequencing, bioinformatics, and genetic engineering. Accordingly, Adaptive Laboratory Evolution (ALE) experiments represent a powerful approach both to investigate the evolutionary forces influencing strain phenotypes, performance, and stability, and to acquire production strains that contain beneficial mutations. In this review, we summarize and categorize the applications of ALE to various aspects of microbial physiology pertinent to industrial bioproduction by collecting case studies that highlight the multitude of ways in which evolution can facilitate the strain construction process. Further, we discuss principles that inform experimental design, complementary approaches such as computational modeling that help maximize utility, and the future of ALE as an efficient strain design and build tool driven by growing adoption and improvements in automation.
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Affiliation(s)
- Troy E Sandberg
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA
| | - Michael J Salazar
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA
| | - Liam L Weng
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA
| | - Bernhard O Palsson
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Lyngby, Denmark
| | - Adam M Feist
- Department of Bioengineering, University of California, San Diego, CA, 92093, USA; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Lyngby, Denmark.
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Belkhelfa S, Roche D, Dubois I, Berger A, Delmas VA, Cattolico L, Perret A, Labadie K, Perdereau AC, Darii E, Pateau E, de Berardinis V, Salanoubat M, Bouzon M, Döring V. Continuous Culture Adaptation of Methylobacterium extorquens AM1 and TK 0001 to Very High Methanol Concentrations. Front Microbiol 2019; 10:1313. [PMID: 31281294 PMCID: PMC6595629 DOI: 10.3389/fmicb.2019.01313] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 05/27/2019] [Indexed: 11/13/2022] Open
Abstract
The bio-economy relies on microbial strains optimized for efficient large scale production of chemicals and fuels from inexpensive and renewable feedstocks under industrial conditions. The reduced one carbon compound methanol, whose production does not involve carbohydrates needed for the feed and food sector, can be used as sole carbon and energy source by methylotrophic bacteria like Methylobacterium extorquens AM1. This strain has already been engineered to produce various commodity and high value chemicals from methanol. The toxic effect of methanol limits its concentration as feedstock to 1% v/v. We obtained M. extorquens chassis strains tolerant to high methanol via adaptive directed evolution using the GM3 technology of automated continuous culture. Turbidostat and conditional medium swap regimes were employed for the parallel evolution of the recently characterized strain TK 0001 and the reference strain AM1 and enabled the isolation of derivatives of both strains capable of stable growth with 10% methanol. The isolates produced more biomass at 1% methanol than the ancestor strains. Genome sequencing identified the gene metY coding for an O-acetyl-L-homoserine sulfhydrylase as common target of mutation. We showed that the wildtype enzyme uses methanol as substrate at elevated concentrations. This side reaction produces methoxine, a toxic homolog of methionine incorporated in polypeptides during translation. All mutated metY alleles isolated from the evolved populations coded for inactive enzymes, designating O-acetyl-L-homoserine sulfhydrylase as a major vector of methanol toxicity. A whole cell transcriptomic analysis revealed that genes coding for chaperones and proteases were upregulated in the evolved cells as compared with the wildtype, suggesting that the cells had to cope with aberrant proteins formed during the adaptation to increasing methanol exposure. In addition, the expression of ribosomal proteins and enzymes related to energy production from methanol like formate dehydrogenases and ATP synthases was boosted in the evolved cells upon a short-term methanol stress. D-lactate production from methanol by adapted cells overexpressing the native D-lactate dehydrogenase was quantified. A significant higher lactate yield was obtained compared with control cells, indicating an enhanced capacity of the cells resistant to high methanol to assimilate this one carbon feedstock more efficiently.
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Affiliation(s)
- Sophia Belkhelfa
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - David Roche
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Ivan Dubois
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Anne Berger
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Valérie A Delmas
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Laurence Cattolico
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Alain Perret
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Karine Labadie
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Aude C Perdereau
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Ekaterina Darii
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Emilie Pateau
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Véronique de Berardinis
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Marcel Salanoubat
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Madeleine Bouzon
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
| | - Volker Döring
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université d'Évry, Université Paris-Saclay, Évry, France
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Zhao J, Zhang H, Qin B, Nikolay R, He QY, Spahn CMT, Zhang G. Multifaceted Stoichiometry Control of Bacterial Operons Revealed by Deep Proteome Quantification. Front Genet 2019; 10:473. [PMID: 31178895 PMCID: PMC6544118 DOI: 10.3389/fgene.2019.00473] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 05/01/2019] [Indexed: 12/03/2022] Open
Abstract
More than half of the protein-coding genes in bacteria are organized in polycistronic operons composed of two or more genes. It remains under debate whether the operon organization maintains the stoichiometric expression of the genes within an operon. In this study, we performed a label-free data-independent acquisition hyper reaction monitoring mass-spectrometry (HRM-MS) experiment to quantify the Escherichia coli proteome in exponential phase and quantified 93.6% of the cytosolic proteins, covering 67.9% and 56.0% of the translating polycistronic operons in BW25113 and MG1655 strains, respectively. We found that the translational regulation contributes largely to the proteome complexity: the shorter operons tend to be more tightly controlled for stoichiometry than longer operons; the operons which mainly code for complexes is more tightly controlled for stoichiometry than the operons which mainly code for metabolic pathways. The gene interval (distance between adjacent genes in one operon) may serve as a regulatory factor for stoichiometry. The catalytic efficiency might be a driving force for differential expression of enzymes encoded in one operon. These results illustrated the multifaceted nature of the operon regulation: the operon unified transcriptional level and gene-specific translational level. This multi-level regulation benefits the host by optimizing the efficiency of the productivity of metabolic pathways and maintenance of different types of protein complexes.
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Affiliation(s)
- Jing Zhao
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou, China
| | - Hong Zhang
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou, China
| | - Bo Qin
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Rainer Nikolay
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Qing-Yu He
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou, China
| | - Christian M T Spahn
- Institut für Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Gong Zhang
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou, China
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Ethanol Stimulates Trehalose Production through a SpoT-DksA-AlgU-Dependent Pathway in Pseudomonas aeruginosa. J Bacteriol 2019; 201:JB.00794-18. [PMID: 30936375 DOI: 10.1128/jb.00794-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/26/2019] [Indexed: 01/06/2023] Open
Abstract
Pseudomonas aeruginosa frequently resides among ethanol-producing microbes, making its response to the microbially produced concentrations of ethanol relevant to understanding its biology. Our transcriptome analysis found that genes involved in trehalose metabolism were induced by low concentrations of ethanol, and biochemical assays showed that levels of intracellular trehalose increased significantly upon growth with ethanol. The increase in trehalose was dependent on the TreYZ pathway but not other trehalose-metabolic enzymes (TreS or TreA). The sigma factor AlgU (AlgT), a homolog of RpoE in other species, was required for increased expression of the treZ gene and trehalose levels, but induction was not controlled by the well-characterized proteolysis of its anti-sigma factor, MucA. Growth with ethanol led to increased SpoT-dependent (p)ppGpp accumulation, which stimulates AlgU-dependent transcription of treZ and other AlgU-regulated genes through DksA, a (p)ppGpp and RNA polymerase binding protein. Ethanol stimulation of trehalose also required acylhomoserine lactone (AHL)-mediated quorum sensing (QS), as induction was not observed in a ΔlasR ΔrhlR strain. A network analysis using a model, eADAGE, built from publicly available P. aeruginosa transcriptome data sets (J. Tan, G. Doing, K. A. Lewis, C. E. Price, et al., Cell Syst 5:63-71, 2017, https://doi.org/10.1016/j.cels.2017.06.003) provided strong support for our model in which treZ and coregulated genes are controlled by both AlgU- and AHL-mediated QS. Consistent with (p)ppGpp- and AHL-mediated quorum-sensing regulation, ethanol, even when added at the time of culture inoculation, stimulated treZ transcript levels and trehalose production in cells from post-exponential-phase cultures but not in cells from exponential-phase cultures. These data highlight the integration of growth and cell density cues in the P. aeruginosa transcriptional response to ethanol.IMPORTANCE Pseudomonas aeruginosa is often found with bacteria and fungi that produce fermentation products, including ethanol. At concentrations similar to those produced by environmental microbes, we found that ethanol stimulated expression of trehalose-biosynthetic genes and cellular levels of trehalose, a disaccharide that protects against environmental stresses. The induction of trehalose by ethanol required the alternative sigma factor AlgU through DksA- and SpoT-dependent (p)ppGpp. Trehalose accumulation also required AHL quorum sensing and occurred only in post-exponential-phase cultures. This work highlights how cells integrate cell density and growth cues in their responses to products made by other microbes and reveals a new role for (p)ppGpp in the regulation of AlgU activity.
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Nshogozabahizi J, Aubrey K, Ross J, Thakor N. Applications and limitations of regulatory
RNA
elements in synthetic biology and biotechnology. J Appl Microbiol 2019; 127:968-984. [DOI: 10.1111/jam.14270] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/09/2019] [Accepted: 03/21/2019] [Indexed: 12/13/2022]
Affiliation(s)
- J.C. Nshogozabahizi
- Department of Chemistry and Biochemistry Alberta RNA Research and Training Institute (ARRTI) University of Lethbridge Lethbridge AB Canada
| | - K.L. Aubrey
- Department of Chemistry and Biochemistry Alberta RNA Research and Training Institute (ARRTI) University of Lethbridge Lethbridge AB Canada
| | - J.A. Ross
- Department of Chemistry and Biochemistry Alberta RNA Research and Training Institute (ARRTI) University of Lethbridge Lethbridge AB Canada
| | - N. Thakor
- Department of Chemistry and Biochemistry Alberta RNA Research and Training Institute (ARRTI) University of Lethbridge Lethbridge AB Canada
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Mohammad F, Green R, Buskirk AR. A systematically-revised ribosome profiling method for bacteria reveals pauses at single-codon resolution. eLife 2019; 8:e42591. [PMID: 30724162 PMCID: PMC6377232 DOI: 10.7554/elife.42591] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 02/05/2019] [Indexed: 12/17/2022] Open
Abstract
In eukaryotes, ribosome profiling provides insight into the mechanism of protein synthesis at the codon level. In bacteria, however, the method has been more problematic and no consensus has emerged for how to best prepare profiling samples. Here, we identify the sources of these problems and describe new solutions for arresting translation and harvesting cells in order to overcome them. These improvements remove confounding artifacts and improve the resolution to allow analyses of ribosome behavior at the codon level. With a clearer view of the translational landscape in vivo, we observe that filtering cultures leads to translational pauses at serine and glycine codons through the reduction of tRNA aminoacylation levels. This observation illustrates how bacterial ribosome profiling studies can yield insight into the mechanism of protein synthesis at the codon level and how these mechanisms are regulated in response to changes in the physiology of the cell.
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Affiliation(s)
- Fuad Mohammad
- Department of Molecular Biology and GeneticsJohns Hopkins University School of MedicineBaltimoreUnited States
| | - Rachel Green
- Department of Molecular Biology and GeneticsJohns Hopkins University School of MedicineBaltimoreUnited States
- Howard Hughes Medical Institute, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Allen R Buskirk
- Department of Molecular Biology and GeneticsJohns Hopkins University School of MedicineBaltimoreUnited States
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Physiological, Genetic, and Transcriptomic Analysis of Alcohol-Induced Delay of Escherichia coli Death. Appl Environ Microbiol 2019; 85:AEM.02113-18. [PMID: 30389772 DOI: 10.1128/aem.02113-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 10/27/2018] [Indexed: 11/20/2022] Open
Abstract
When Escherichia coli K-12 is inoculated into rich medium in batch culture, cells experience five phases. While the lag and logarithmic phases are mechanistically fairly well defined, the stationary phase, death phase, and long-term stationary phase are less well understood. Here, we characterize a mechanism of delaying death, a phenomenon we call the "alcohol effect," where the addition of small amounts of certain alcohols prolongs stationary phase for at least 10 days longer than in untreated conditions. We show that the stationary phase is extended when ethanol is added above a minimum threshold concentration. Once ethanol levels fall below a threshold concentration, cells enter the death phase. We also show that the effect is conferred by the addition of straight-chain alcohols 1-propanol, 1-butanol, 1-pentanol, and, to a lesser degree, 1-hexanol. However, methanol, isopropanol, 1-heptanol, and 1-octanol do not delay entry into death phase. Though modulated by RpoS, the alcohol effect does not require RpoS activity or the activities of the AdhE or AdhP alcohol dehydrogenases. Further, we show that ethanol is capable of extending the life span of stationary-phase cultures for non-K-12 E. coli strains and that this effect is caused in part by genes of the glycolate degradation pathway. These data suggest a model where ethanol and other shorter 1-alcohols can serve as signaling molecules, perhaps by modulating patterns of gene expression that normally regulate the transition from stationary phase to death phase.IMPORTANCE In one of the most well-studied organisms in the life sciences, Escherichia coli, we still do not fully understand what causes populations to die. This is largely due to the technological difficulties of studying bacterial cell death. This study provides an avenue to studying how and why E. coli populations, and perhaps other microbes, transition from stationary phase to death phase by exploring how ethanol and other alcohols delay the onset of death. Here, we demonstrate that alcohols are acting as signaling molecules to achieve the delay in death phase. This study not only offers a better understanding of a fundamental process but perhaps also provides a gateway to studying the dynamics between ethanol and microbes in the human gastrointestinal tract.
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Song X, Sun Y, Zhang Q, Yang X, Zheng F, He S, Wang Y. Failure of Staphylococcus aureus to Acquire Direct and Cross Tolerance after Habituation to Cinnamon Essential Oil. Microorganisms 2019; 7:E18. [PMID: 30641977 PMCID: PMC6352263 DOI: 10.3390/microorganisms7010018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/06/2019] [Accepted: 01/08/2019] [Indexed: 11/16/2022] Open
Abstract
Utilization of sublethal concentrations of cinnamon essential oil (CEO) for food preservation has been proposed. However, exposure to stressful, sublethal growth conditions may induce bacterial tolerance to homologous or heterologous stressing agents. Hence, the ability of CEO to stimulate bacterial stress response was evaluated in the current work. Staphylococcus aureus was exposed to 1/4 and 1/2 of the minimum inhibitory concentration (MIC, 500 μL/L) of CEO for 18 h. It was found that overnight habituation to CEO failed to induce direct tolerance and cross-tolerance to lactic acid (pH 4.5), NaCl (10 g/100 mL) and high temperature (45 °C) in S. aureus. Likewise, S. aureus cells subjected to successive habituation with increasing amounts (1/16 MIC to 2× MIC) of CEO developed no direct tolerance. Taken together, CEO has no inductive effect on the acquisition of stress tolerance in S. aureus.
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Affiliation(s)
- Xiaoqiu Song
- School of Perfume and Aroma Technology, Shanghai Institute of Technology, Haiquan Road 100, Shanghai 201418, China.
| | - Yue Sun
- School of Perfume and Aroma Technology, Shanghai Institute of Technology, Haiquan Road 100, Shanghai 201418, China.
| | - Qian Zhang
- School of Perfume and Aroma Technology, Shanghai Institute of Technology, Haiquan Road 100, Shanghai 201418, China.
| | - Xiaobo Yang
- School of Perfume and Aroma Technology, Shanghai Institute of Technology, Haiquan Road 100, Shanghai 201418, China.
| | - Feng Zheng
- School of Perfume and Aroma Technology, Shanghai Institute of Technology, Haiquan Road 100, Shanghai 201418, China.
| | - Shoukui He
- School of Perfume and Aroma Technology, Shanghai Institute of Technology, Haiquan Road 100, Shanghai 201418, China.
| | - Yifei Wang
- School of Perfume and Aroma Technology, Shanghai Institute of Technology, Haiquan Road 100, Shanghai 201418, China.
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Li H, Mei X, Liu B, Xie G, Ren N, Xing D. Quantitative proteomic analysis reveals the ethanologenic metabolism regulation of Ethanoligenens harbinense by exogenous ethanol addition. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:166. [PMID: 31297154 PMCID: PMC6598285 DOI: 10.1186/s13068-019-1511-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 06/19/2019] [Indexed: 05/21/2023]
Abstract
BACKGROUND H2-ethanol-coproducing bacteria, as primary fermenters, play important roles in the microbiome of bioreactors for bioenergy production from organic wastewater or solid wastes. Ethanoligenens harbinense YUAN-3 is an anaerobic ethanol-H2-fermenting bacterium. Ethanol is one of the main end-products of strain YUAN-3 that influence its fermentative process. Until recently, the molecular mechanism of metabolic regulation in strain YUAN-3 during ethanol accumulation has still been unclear. This study aims to elucidate the metabolic regulation mechanisms in strain YUAN-3, which contributes to effectively shape the microbiome for biofuel and bioenergy production from waste stream. RESULTS This study reports that ethanol stress altered the distribution of end-product yields in the H2-ethanol-coproducing Ethanoligenens harbinense strain YUAN-3. Decreasing trends of hydrogen yield from 1888.6 ± 45.8 to 837 ± 64.7 mL L-1 and acetic acid yield from 1767.7 ± 45 to 160.6 ± 44.7 mg L-1 were observed in strain YUAN-3 with increasing exogenous ethanol (0 mM-200 mM). However, the ethanol yield of strain YUAN-3 increased by 15.1%, 30.1%, and 27.4% in 50 mM, 100 mM, and 200 mM ethanol stress, respectively. The endogenous ethanol accounted for 96.1% (w/w) in liquid end-products when exogenous ethanol of 200 mM was added. The molar ratio of ethanol to acetic acid increased 14 times (exogenous ethanol of 200 mM) compared to the control. iTRAQ-based quantitative proteomic analysis indicated that 263 proteins of strain YUAN-3 were differentially expressed in 50 mM, 100 mM, and 200 mM of exogenous ethanol. These proteins are mainly involved in amino acid transport and metabolism, central carbon metabolism, and oxidative stress response. CONCLUSION These differentially expressed proteins play important roles in metabolic changes necessary for growth and survival of strain YUAN-3 during ethanol stress. The up-regulation of bifunctional acetaldehyde-CoA/alcohol dehydrogenase (ADHE) was the main reason why ethanol production was enhanced, while hydrogen gas and acetic acid yields declined in strain YUAN-3 during ethanol stress. This study also provides a new approach for the enhancement of ethanologenesis by H2-ethanol-coproducing bacteria through exogenous ethanol addition.
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Affiliation(s)
- Huahua Li
- State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, P.O. Box 2614, No. 73 Huanghe Road, Nangang District, Harbin, 150090 Heilongjiang China
| | - Xiaoxue Mei
- State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, P.O. Box 2614, No. 73 Huanghe Road, Nangang District, Harbin, 150090 Heilongjiang China
| | - Bingfeng Liu
- State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, P.O. Box 2614, No. 73 Huanghe Road, Nangang District, Harbin, 150090 Heilongjiang China
| | - Guojun Xie
- State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, P.O. Box 2614, No. 73 Huanghe Road, Nangang District, Harbin, 150090 Heilongjiang China
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, P.O. Box 2614, No. 73 Huanghe Road, Nangang District, Harbin, 150090 Heilongjiang China
| | - Defeng Xing
- State Key Laboratory of Urban Water Resources and Environment, School of Environment, Harbin Institute of Technology, P.O. Box 2614, No. 73 Huanghe Road, Nangang District, Harbin, 150090 Heilongjiang China
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Abstract
Ribosome profiling provides information on the position of ribosomes on mRNA on a genomic scale. Although this information is often used to detect changes in gene expression under different conditions, it also has great potential for yielding insight into the mechanism and regulation of protein synthesis itself. First developed in yeast, ribosome profiling involves the isolation and sequencing of ribosome-protected mRNA fragments generated by nuclease treatment. Since the application of ribosome profiling in bacteria has been problematic, we report here a systematically optimized protocol for E. coli that we have used with success for other bacteria as well. Cells are harvested by flash-freezing cultures directly in liquid nitrogen. After lysis, translation is arrested by high magnesium concentration without the use of antibiotics. These improvements eliminate artifacts induced by harvesting cells by centrifugation or filtration and by use of chloramphenicol to arrest translation. These improvements are especially appropriate for studies where the exact position of the ribosome is critical, and not merely the number of ribosomes per message, such as studies aimed at monitoring differences in local elongation rates.
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Affiliation(s)
- Fuad Mohammad
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Allen R Buskirk
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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