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Liljegren MM, Gama JA, Johnsen PJ, Harms K. The recombination initiation functions DprA and RecFOR suppress microindel mutations in Acinetobacter baylyi ADP1. Mol Microbiol 2024; 122:1-10. [PMID: 38760330 DOI: 10.1111/mmi.15277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 04/24/2024] [Accepted: 04/26/2024] [Indexed: 05/19/2024]
Abstract
Short-Patch Double Illegitimate Recombination (SPDIR) has been recently identified as a rare mutation mechanism. During SPDIR, ectopic DNA single-strands anneal with genomic DNA at microhomologies and get integrated during DNA replication, presumably acting as primers for Okazaki fragments. The resulting microindel mutations are highly variable in size and sequence. In the soil bacterium Acinetobacter baylyi, SPDIR is tightly controlled by genome maintenance functions including RecA. It is thought that RecA scavenges DNA single-strands and renders them unable to anneal. To further elucidate the role of RecA in this process, we investigate the roles of the upstream functions DprA, RecFOR, and RecBCD, all of which load DNA single-strands with RecA. Here we show that all three functions suppress SPDIR mutations in the wildtype to levels below the detection limit. While SPDIR mutations are slightly elevated in the absence of DprA, they are strongly increased in the absence of both DprA and RecA. This SPDIR-avoiding function of DprA is not related to its role in natural transformation. These results suggest a function for DprA in combination with RecA to avoid potentially harmful microindel mutations, and offer an explanation for the ubiquity of dprA in the genomes of naturally non-transformable bacteria.
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Affiliation(s)
- Mikkel M Liljegren
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
| | - João A Gama
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Madrid, Spain
| | - Pål J Johnsen
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
| | - Klaus Harms
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
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2
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Ishikawa M, Hori K. The elimination of two restriction enzyme genes allows for electroporation-based transformation and CRISPR-Cas9-based base editing in the non-competent Gram-negative bacterium Acinetobacter sp. Tol 5. Appl Environ Microbiol 2024; 90:e0040024. [PMID: 38722179 PMCID: PMC11218613 DOI: 10.1128/aem.00400-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 04/06/2024] [Indexed: 06/19/2024] Open
Abstract
Environmental isolates are promising candidates for new chassis of synthetic biology because of their inherent capabilities, which include efficiently converting a wide range of substrates into valuable products and resilience to environmental stresses; however, many remain genetically intractable and unamenable to established genetic tools tailored for model bacteria. Acinetobacter sp. Tol 5, an environmentally isolated Gram-negative bacterium, possesses intriguing properties for use in synthetic biology applications. Despite the previous development of genetic tools for the engineering of strain Tol 5, its genetic manipulation has been hindered by low transformation efficiency via electroporation, rendering the process laborious and time-consuming. This study demonstrated the genetic refinement of the Tol 5 strain, achieving efficient transformation via electroporation. We deleted two genes encoding type I and type III restriction enzymes. The resulting mutant strain not only exhibited marked efficiency of electrotransformation but also proved receptive to both in vitro and in vivo DNA assembly technologies, thereby facilitating the construction of recombinant DNA without reliance on intermediate Escherichia coli constructs. In addition, we successfully adapted a CRISPR-Cas9-based base-editing platform developed for other Acinetobacter species. Our findings provide genetic modification strategies that allow for the domestication of environmentally isolated bacteria, streamlining their utilization in synthetic biology applications.IMPORTANCERecent synthetic biology has sought diverse bacterial chassis from environmental sources to circumvent the limitations of laboratory Escherichia coli strains for industrial and environmental applications. One of the critical barriers in cell engineering of bacterial chassis is their inherent resistance to recombinant DNA, propagated either in vitro or within E. coli cells. Environmental bacteria have evolved defense mechanisms against foreign DNA as a response to the constant threat of phage infection. The ubiquity of phages in natural settings accounts for the genetic intractability of environmental isolates. The significance of our research is in demonstrating genetic modification strategies for the cell engineering of such genetically intractable bacteria. This research marks a pivotal step in the domestication of environmentally isolated bacteria, promising candidates for emerging synthetic biology chassis. Our work thus significantly contributes to advancing their applications across industrial, environmental, and biomedical fields.
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Affiliation(s)
- Masahito Ishikawa
- Department of Frontier Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga, Japan
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
| | - Katsutoshi Hori
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Nagoya, Japan
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Meriläinen E, Efimova E, Santala V, Santala S. Carbon-wise utilization of lignin-related compounds by synergistically employing anaerobic and aerobic bacteria. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:78. [PMID: 38851749 PMCID: PMC11161944 DOI: 10.1186/s13068-024-02526-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024]
Abstract
BACKGROUND Lignin is a highly abundant but strongly underutilized natural resource that could serve as a sustainable feedstock for producing chemicals by microbial cell factories. Because of the heterogeneous nature of the lignin feedstocks, the biological upgrading of lignin relying on the metabolic routes of aerobic bacteria is currently considered as the most promising approach. However, the limited substrate range and the inefficient catabolism of the production hosts hinder the upgrading of lignin-related aromatics. Particularly, the aerobic O-demethylation of the methoxyl groups in aromatic substrates is energy-limited, inhibits growth, and results in carbon loss in the form of CO2. RESULTS In this study, we present a novel approach for carbon-wise utilization of lignin-related aromatics by the integration of anaerobic and aerobic metabolisms. In practice, we employed an acetogenic bacterium Acetobacterium woodii for anaerobic O-demethylation of aromatic compounds, which distinctively differs from the aerobic O-demethylation; in the process, the carbon from the methoxyl groups is fixed together with CO2 to form acetate, while the aromatic ring remains unchanged. These accessible end-metabolites were then utilized by an aerobic bacterium Acinetobacter baylyi ADP1. By utilizing this cocultivation approach, we demonstrated an upgrading of guaiacol, an abundant but inaccessible substrate to most microbes, into a plastic precursor muconate, with a nearly equimolar yields (0.9 mol/mol in a small-scale cultivation and 1.0 mol/mol in a one-pot bioreactor cultivation). The process required only a minor genetic engineering, namely a single gene knock-out. Noticeably, by employing a metabolic integration of the two bacteria, it was possible to produce biomass and muconate by utilizing only CO2 and guaiacol as carbon sources. CONCLUSIONS By the novel approach, we were able to overcome the issues related to aerobic O-demethylation of methoxylated aromatic substrates and demonstrated carbon-wise conversion of lignin-related aromatics to products with yields unattainable by aerobic processes. This study highlights the power of synergistic integration of distinctive metabolic features of bacteria, thus unlocking new opportunities for harnessing microbial cocultures in upgrading challenging feedstocks.
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Affiliation(s)
- Ella Meriläinen
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Ville Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland.
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4
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Ellison TJ, Ellison CK. DNA binding is rate-limiting for natural transformation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.06.597730. [PMID: 38895488 PMCID: PMC11185590 DOI: 10.1101/2024.06.06.597730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Bacteria take up environmental DNA using dynamic appendages called type IV pili (T4P) to elicit horizontal gene transfer in a process called natural transformation. Natural transformation is widespread amongst bacteria yet determining how different factors universally contribute to or limit this process across species has remained challenging. Here we show that Acinetobacter baylyi, the most naturally transformable species, is highly transformable due to its ability to robustly bind nonspecific DNA via a dedicated orphan minor pilin, FimT. We show that, compared to its homologues, A. baylyi FimT contains multiple positively charged residues that additively promote DNA binding efficiency. Expression of A. baylyi FimT in a closely related Acinetobacter pathogen is sufficient to substantially improve its capacity for natural transformation, demonstrating that T4P-DNA binding is a rate-limiting step in this process. These results demonstrate the importance of T4P-DNA binding efficiency in driving natural transformation, establishing a key factor limiting horizontal gene transfer.
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Liu C, Choi B, Efimova E, Nygård Y, Santala S. Enhanced upgrading of lignocellulosic substrates by coculture of Saccharomyces cerevisiae and Acinetobacter baylyi ADP1. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:61. [PMID: 38711153 DOI: 10.1186/s13068-024-02510-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 04/23/2024] [Indexed: 05/08/2024]
Abstract
BACKGROUND Lignocellulosic biomass as feedstock has a huge potential for biochemical production. Still, efficient utilization of hydrolysates derived from lignocellulose is challenged by their complex and heterogeneous composition and the presence of inhibitory compounds, such as furan aldehydes. Using microbial consortia where two specialized microbes complement each other could serve as a potential approach to improve the efficiency of lignocellulosic biomass upgrading. RESULTS This study describes the simultaneous inhibitor detoxification and production of lactic acid and wax esters from a synthetic lignocellulosic hydrolysate by a defined coculture of engineered Saccharomyces cerevisiae and Acinetobacter baylyi ADP1. A. baylyi ADP1 showed efficient bioconversion of furan aldehydes present in the hydrolysate, namely furfural and 5-hydroxymethylfurfural, and did not compete for substrates with S. cerevisiae, highlighting its potential as a coculture partner. Furthermore, the remaining carbon sources and byproducts of S. cerevisiae were directed to wax ester production by A. baylyi ADP1. The lactic acid productivity of S. cerevisiae was improved approximately 1.5-fold (to 0.41 ± 0.08 g/L/h) in the coculture with A. baylyi ADP1, compared to a monoculture of S. cerevisiae. CONCLUSION The coculture of yeast and bacterium was shown to improve the consumption of lignocellulosic substrates and the productivity of lactic acid from a synthetic lignocellulosic hydrolysate. The high detoxification capacity and the ability to produce high-value products by A. baylyi ADP1 demonstrates the strain to be a potential candidate for coculture to increase production efficiency and economics of S. cerevisiae fermentations.
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Affiliation(s)
- Changshuo Liu
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Tampere, Finland
| | - Bohyun Choi
- Department of Life Sciences, Industrial Biotechnology, Chalmers University of Technology, Gothenburg, Sweden
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Tampere, Finland
| | - Yvonne Nygård
- Department of Life Sciences, Industrial Biotechnology, Chalmers University of Technology, Gothenburg, Sweden
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Tampere, Finland.
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6
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Yin CF, Nie Y, Li T, Zhou NY. AlmA involved in the long-chain n-alkane degradation pathway in Acinetobacter baylyi ADP1 is a Baeyer-Villiger monooxygenase. Appl Environ Microbiol 2024; 90:e0162523. [PMID: 38168668 PMCID: PMC10807437 DOI: 10.1128/aem.01625-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 11/22/2023] [Indexed: 01/05/2024] Open
Abstract
Many Acinetobacter species can grow on n-alkanes of varying lengths (≤C40). AlmA, a unique flavoprotein in these Acinetobacter strains, is the only enzyme proven to be required for the degradation of long-chain (LC) n-alkanes, including C32 and C36 alkanes. Although it is commonly presumed to be a terminal hydroxylase, its role in n-alkane degradation remains elusive. In this study, we conducted physiological, biochemical, and bioinformatics analyses of AlmA to determine its role in n-alkane degradation by Acinetobacter baylyi ADP1. Consistent with previous reports, gene deletion analysis showed that almA was vital for the degradation of LC n-alkanes (C26-C36). Additionally, enzymatic analysis revealed that AlmA catalyzed the conversion of aliphatic 2-ketones (C10-C16) to their corresponding esters, but it did not conduct n-alkane hydroxylation under the same conditions, thus suggesting that AlmA in strain ADP1 possesses Baeyer-Villiger monooxygenase (BVMO) activity. These results were further confirmed by bioinformatics analysis, which revealed that AlmA was closer to functionally identified BVMOs than to hydroxylases. Altogether, the results of our study suggest that LC n-alkane degradation by strain ADP1 possibly follows a novel subterminal oxidation pathway that is distinct from the terminal oxidation pathway followed for short-chain n-alkane degradation. Furthermore, our findings suggest that AlmA catalyzes the third reaction in the LC n-alkane degradation pathway.IMPORTANCEMany microbial studies on n-alkane degradation are focused on the genes involved in short-chain n-alkane (≤C16) degradation; however, reports on the genes involved in long-chain (LC) n-alkane (>C20) degradation are limited. Thus far, only AlmA has been reported to be involved in LC n-alkane degradation by Acinetobacter spp.; however, its role in the n-alkane degradation pathway remains elusive. In this study, we conducted a detailed characterization of AlmA in A. baylyi ADP1 and found that AlmA exhibits Baeyer-Villiger monooxygenase activity, thus indicating the presence of a novel LC n-alkane biodegradation mechanism in strain ADP1.
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Affiliation(s)
- Chao-Fan Yin
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yong Nie
- College of Engineering, Peking University, Beijing, China
| | - Tao Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Ning-Yi Zhou
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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7
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Zampaloni C, Mattei P, Bleicher K, Winther L, Thäte C, Bucher C, Adam JM, Alanine A, Amrein KE, Baidin V, Bieniossek C, Bissantz C, Boess F, Cantrill C, Clairfeuille T, Dey F, Di Giorgio P, du Castel P, Dylus D, Dzygiel P, Felici A, García-Alcalde F, Haldimann A, Leipner M, Leyn S, Louvel S, Misson P, Osterman A, Pahil K, Rigo S, Schäublin A, Scharf S, Schmitz P, Stoll T, Trauner A, Zoffmann S, Kahne D, Young JAT, Lobritz MA, Bradley KA. A novel antibiotic class targeting the lipopolysaccharide transporter. Nature 2024; 625:566-571. [PMID: 38172634 PMCID: PMC10794144 DOI: 10.1038/s41586-023-06873-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 11/16/2023] [Indexed: 01/05/2024]
Abstract
Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as a major global pathogen with limited treatment options1. No new antibiotic chemical class with activity against A. baumannii has reached patients in over 50 years1. Here we report the identification and optimization of tethered macrocyclic peptide (MCP) antibiotics with potent antibacterial activity against CRAB. The mechanism of action of this molecule class involves blocking the transport of bacterial lipopolysaccharide from the inner membrane to its destination on the outer membrane, through inhibition of the LptB2FGC complex. A clinical candidate derived from the MCP class, zosurabalpin (RG6006), effectively treats highly drug-resistant contemporary isolates of CRAB both in vitro and in mouse models of infection, overcoming existing antibiotic resistance mechanisms. This chemical class represents a promising treatment paradigm for patients with invasive infections due to CRAB, for whom current treatment options are inadequate, and additionally identifies LptB2FGC as a tractable target for antimicrobial drug development.
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Affiliation(s)
- Claudia Zampaloni
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Patrizio Mattei
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Konrad Bleicher
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- SixPeaks Bio, Basel, Switzerland
| | - Lotte Winther
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Claudia Thäte
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- Preclinical Sciences and Translational Safety, Janssen Pharmaceutica, Beerse, Belgium
| | - Christian Bucher
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Jean-Michel Adam
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- AutoChem R&D, Mettler-Toledo International, Greifensee, Switzerland
| | - Alexander Alanine
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- Independent consultant, Cambridge, Great Britain
| | - Kurt E Amrein
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Vadim Baidin
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Christoph Bieniossek
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Caterina Bissantz
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Franziska Boess
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Carina Cantrill
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Thomas Clairfeuille
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Fabian Dey
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Patrick Di Giorgio
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Pauline du Castel
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - David Dylus
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Pawel Dzygiel
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Antonio Felici
- Discovery Microbiology, Aptuit (Verona) Srl, an Evotec Company, Verona, Italy
| | - Fernando García-Alcalde
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Andreas Haldimann
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Matthew Leipner
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Semen Leyn
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Séverine Louvel
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Pauline Misson
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Andrei Osterman
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Karanbir Pahil
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Sébastien Rigo
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Adrian Schäublin
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- SixPeaks Bio, Basel, Switzerland
| | - Sebastian Scharf
- Roche Pharma Research and Early Development, Informatics, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Petra Schmitz
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Theodor Stoll
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Andrej Trauner
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Sannah Zoffmann
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- Therapeutics Discovery, Janssen Pharmaceutica, Beerse, Belgium
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - John A T Young
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Michael A Lobritz
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland.
| | - Kenneth A Bradley
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland.
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8
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Pahil KS, Gilman MSA, Baidin V, Clairfeuille T, Mattei P, Bieniossek C, Dey F, Muri D, Baettig R, Lobritz M, Bradley K, Kruse AC, Kahne D. A new antibiotic traps lipopolysaccharide in its intermembrane transporter. Nature 2024; 625:572-577. [PMID: 38172635 PMCID: PMC10794137 DOI: 10.1038/s41586-023-06799-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 10/30/2023] [Indexed: 01/05/2024]
Abstract
Gram-negative bacteria are extraordinarily difficult to kill because their cytoplasmic membrane is surrounded by an outer membrane that blocks the entry of most antibiotics. The impenetrable nature of the outer membrane is due to the presence of a large, amphipathic glycolipid called lipopolysaccharide (LPS) in its outer leaflet1. Assembly of the outer membrane requires transport of LPS across a protein bridge that spans from the cytoplasmic membrane to the cell surface. Maintaining outer membrane integrity is essential for bacterial cell viability, and its disruption can increase susceptibility to other antibiotics2-6. Thus, inhibitors of the seven lipopolysaccharide transport (Lpt) proteins that form this transenvelope transporter have long been sought. A new class of antibiotics that targets the LPS transport machine in Acinetobacter was recently identified. Here, using structural, biochemical and genetic approaches, we show that these antibiotics trap a substrate-bound conformation of the LPS transporter that stalls this machine. The inhibitors accomplish this by recognizing a composite binding site made up of both the Lpt transporter and its LPS substrate. Collectively, our findings identify an unusual mechanism of lipid transport inhibition, reveal a druggable conformation of the Lpt transporter and provide the foundation for extending this class of antibiotics to other Gram-negative pathogens.
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Affiliation(s)
- Karanbir S Pahil
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Morgan S A Gilman
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Vadim Baidin
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Thomas Clairfeuille
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Patrizio Mattei
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Christoph Bieniossek
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Fabian Dey
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Dieter Muri
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Remo Baettig
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Michael Lobritz
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Kenneth Bradley
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Andrew C Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
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9
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Bailey J, Gallagher L, Manoil C. Genome-scale analysis of essential gene knockout mutants to identify an antibiotic target process. Antimicrob Agents Chemother 2023; 67:e0110223. [PMID: 37966228 PMCID: PMC10720506 DOI: 10.1128/aac.01102-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 09/22/2023] [Indexed: 11/16/2023] Open
Abstract
We describe a genome-scale approach to identify the essential biological process targeted by a new antibiotic. The procedure is based on the identification of essential genes whose inactivation sensitizes a Gram-negative bacterium (Acinetobacter baylyi) to a drug and employs recently developed transposon mutant screening and single-mutant validation procedures. The approach, based on measuring the rates of loss of newly generated knockout mutants in the presence of antibiotic, provides an alternative to traditional procedures for studying essential functions using conditional expression or activity alleles. As a proof of principle study, we evaluated whether mutations enhancing sensitivity to the β-lactam antibiotic meropenem corresponded to the known essential target process of the antibiotic (septal peptidoglycan synthesis). We found that indeed mutations inactivating most genes needed for peptidoglycan synthesis and cell division strongly sensitized cells to meropenem. Additional classes of sensitizing mutations in essential genes were also identified, including those that inactivated capsule synthesis, DNA replication, or envelope stress response regulation. The essential capsule synthesis mutants appeared to enhance meropenem sensitivity by depleting a precursor needed for both capsule and peptidoglycan synthesis. The replication mutants may sensitize cells by impairing division. Nonessential gene mutations sensitizing cells to meropenem were also identified in the screen and largely corresponded to functions subordinately associated with the essential target process, such as in peptidoglycan recycling. Overall, these results help validate a new approach to identify the essential process targeted by an antibiotic and define the larger functional network determining sensitivity to it.
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Affiliation(s)
- J. Bailey
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - L. Gallagher
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - C. Manoil
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
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10
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Zhang S, Xu B, Chen M, Zhang Q, Huang J, Cao Y, Li B. Profile and actual transmissibility of Carbapenem resistance genes: Intracellular and extracellular DNA in hospital wastewater. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 329:117085. [PMID: 36571956 DOI: 10.1016/j.jenvman.2022.117085] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 12/13/2022] [Accepted: 12/17/2022] [Indexed: 05/10/2023]
Abstract
The current worldwide spread of carbapenem resistance genes (CRGs) has posed a major public health threat, which continues to grow in severity. Hospital wastewaters (HWWs) are major reservoirs for antibiotic resistance genes, while resistomes in HWWs are still poorly characterized when it comes to CRGs. We comprehensively characterized the profile and actual transmissibility of extracellular CRGs (eCRGs) and intracellular CRGs (iCRGs) in HWWs for the first time. In this study, CRGs showed similar relative abundance in treated and untreated HWWs. Meanwhile, HWWs treatments led to the enrichment of blaIMP-8, probably attributed to the promotion of Novosphingobium and Prosthecobacter after treatment. To evaluate the transmission potential of CRGs, extracellular and intracellular carbapenem-resistant plasmids were captured from HWWs by transformation and conjugation, respectively. We found an interesting phenomenon regarding the transmission characteristics of CRGs: blaKPC-carrying plasmids could only be captured by transformation, while blaNDM-carrying plasmids were captured by conjugation. Further experiments showed that HWW treatments increased the conjugation ability of blaNDM. In conclusion, our study demonstrated that HWWs are significant reservoirs of CRGs and various CRGs exhibit different modes of transmission in HWWs. CRGs cannot be removed by membrane bioreactor and chlorine disinfection. An urgent need is to develop more efficient wastewater treatments to limit CRG dissemination.
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Affiliation(s)
- Shengcen Zhang
- Department of Clinical Laboratory, Fujian Medical University Union Hospital, Fuzhou, Fujian, 350001, China
| | - Binbin Xu
- Department of Clinical Laboratory, Fujian Medical University Union Hospital, Fuzhou, Fujian, 350001, China
| | - Mo Chen
- Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fujian Medical University Union Hospital, Fuzhou, Fujian,350001, China
| | - Qianwen Zhang
- Department of Clinical Laboratory, Fujian Medical University Union Hospital, Fuzhou, Fujian, 350001, China
| | - Jiangqing Huang
- Department of Clinical Laboratory, Fujian Medical University Union Hospital, Fuzhou, Fujian, 350001, China
| | - Yingping Cao
- Department of Clinical Laboratory, Fujian Medical University Union Hospital, Fuzhou, Fujian, 350001, China
| | - Bin Li
- Department of Clinical Laboratory, Fujian Medical University Union Hospital, Fuzhou, Fujian, 350001, China.
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11
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Zhao Y, Wei HM, Yuan JL, Xu L, Sun JQ. A comprehensive genomic analysis provides insights on the high environmental adaptability of Acinetobacter strains. Front Microbiol 2023; 14:1177951. [PMID: 37138596 PMCID: PMC10149724 DOI: 10.3389/fmicb.2023.1177951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 03/28/2023] [Indexed: 05/05/2023] Open
Abstract
Acinetobacter is ubiquitous, and it has a high species diversity and a complex evolutionary pattern. To elucidate the mechanism of its high ability to adapt to various environment, 312 genomes of Acinetobacter strains were analyzed using the phylogenomic and comparative genomics methods. It was revealed that the Acinetobacter genus has an open pan-genome and strong genome plasticity. The pan-genome consists of 47,500 genes, with 818 shared by all the genomes of Acinetobacter, while 22,291 are unique genes. Although Acinetobacter strains do not have a complete glycolytic pathway to directly utilize glucose as carbon source, most of them harbored the n-alkane-degrading genes alkB/alkM (97.1% of tested strains) and almA (96.7% of tested strains), which were responsible for medium-and long-chain n-alkane terminal oxidation reaction, respectively. Most Acinetobacter strains also have catA (93.3% of tested strains) and benAB (92.0% of tested strains) genes that can degrade the aromatic compounds catechol and benzoic acid, respectively. These abilities enable the Acinetobacter strains to easily obtain carbon and energy sources from their environment for survival. The Acinetobacter strains can manage osmotic pressure by accumulating potassium and compatible solutes, including betaine, mannitol, trehalose, glutamic acid, and proline. They respond to oxidative stress by synthesizing superoxide dismutase, catalase, disulfide isomerase, and methionine sulfoxide reductase that repair the damage caused by reactive oxygen species. In addition, most Acinetobacter strains contain many efflux pump genes and resistance genes to manage antibiotic stress and can synthesize a variety of secondary metabolites, including arylpolyene, β-lactone and siderophores among others, to adapt to their environment. These genes enable Acinetobacter strains to survive extreme stresses. The genome of each Acinetobacter strain contained different numbers of prophages (0-12) and genomic islands (GIs) (6-70), and genes related to antibiotic resistance were found in the GIs. The phylogenetic analysis revealed that the alkM and almA genes have a similar evolutionary position with the core genome, indicating that they may have been acquired by vertical gene transfer from their ancestor, while catA, benA, benB and the antibiotic resistance genes could have been acquired by horizontal gene transfer from the other organisms.
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Affiliation(s)
- Yang Zhao
- Lab for Microbial Resources, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Hua-Mei Wei
- Lab for Microbial Resources, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Jia-Li Yuan
- Lab for Microbial Resources, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Lian Xu
- Jiangsu Key Lab for Organic Solid Waste Utilization, Educational Ministry Engineering Center of Resource-Saving Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Ji-Quan Sun
- Lab for Microbial Resources, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
- *Correspondence: Ji-Quan Sun,
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12
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Terkuran M, Erginkaya Z, Konuray G, Meral M, Ünal N, Yaşar S, Köksal F. Evaluation of Antibiotic Resistance and adeABC, adeR, adeS Efflux Pump Genes among Foodborne and Clinical Acinetobacter spp. in Türkiye. IRANIAN JOURNAL OF PUBLIC HEALTH 2022; 51:2753-2763. [PMID: 36742236 PMCID: PMC9874188 DOI: 10.18502/ijph.v51i12.11466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/14/2022] [Indexed: 12/29/2022]
Abstract
Background The adeABC efflux pump has a crucial role in the resistance of Acinetobacter baumannii strains to antimicrobial agents; it is encoded by adeABC, adeR, adeS genes. We evaluated antibiotic resistance, efflux pump genes, clonal relationships, and analyzed a probable correlation that can exist between antibiotic resistance and the aforementioned genes. Methods We conducted this study on 27 food-originated and 50 human clinical Acinetobacter spp. in Southern Türkiye. MALDI-TOF system and disc diffusion/agar dilution (colistin) methods were used for the identification and antibiotic susceptibility. The efflux pump genes and genetic relatedness of the two groups were investigated by (PCR) and (PFGE) methods. Results Foodborne A. dijkshoorniae strain was multidrug- resistant (MDR), and none of them resistant to colistin. Most of the clinical isolates (92%) were Extensive-Drug Resistant (XDR); highest resistant to ceftazidime, piperacillin-tazobactam, and imipenem (47, 94%), and were lowest to colistin (7, 14%), respectively. adeABC, and adeR, adeS genes were (23, 85.2%), (9, 33.3%), (27, 100%) and (10, 37.3%), (18, 66.7%) in foodborne strains respectively. These rates were (43, 86%), (48, 96%), (50, 100%), and (34, 68%), (48, 96.7%) in clinical strains respectively. A positive correlation existed between adeA gene positivity and piperacillintazobactam, ceftazidime, gentamycin, imipenem (P=0.048), amikacin (P=0.007) and trimethoprimsulfamethoxazole (P=0.029) resistance in clinical strains. A positive correlation of trimethoprimsulfamethoxazole resistance and adeS gene positivity was seen in foodborne strains (P=0.018). Conclusion Multiple-efflux pump genes rise in parallel to multidrug-resistance in clinical isolates, while susceptible to diverse antibiotics; food may be a potential provenance for the dissemination of adeABC, adeR and adeS genes.
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Affiliation(s)
- Mevhibe Terkuran
- Department of Gastronomy and Culinary Arts, Faculty of Kadirli Applied Science, University of Osmaniye Korkut Ata, Osmaniye, Türkiye,Corresponding Author:
| | - Zerrin Erginkaya
- Department of Food Engineering, Faculty of Agriculture, Çukurova University, Adana, Türkiye
| | - Gözde Konuray
- Department of Food Engineering, Faculty of Agriculture, Çukurova University, Adana, Türkiye
| | - Melda Meral
- Department of Clinical Microbiology, Faculty of Medicine, Çukurova University, Adana, Türkiye
| | - Nevzat Ünal
- Adana City Training and Research Hospital, Medical Microbiology, Adana, Türkiye
| | - Sertdemir Yaşar
- Department of Biostatistics, Faculty of Medicine, Çukurova University, Adana, Türkiye
| | - Fatih Köksal
- Department of Clinical Microbiology, Faculty of Medicine, Çukurova University, Adana, Türkiye
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13
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Luo J, Efimova E, Volke DC, Santala V, Santala S. Engineering cell morphology by CRISPR interference in Acinetobacter baylyi ADP1. Microb Biotechnol 2022; 15:2800-2818. [PMID: 36005297 DOI: 10.1111/1751-7915.14133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 07/29/2022] [Accepted: 08/08/2022] [Indexed: 11/26/2022] Open
Abstract
Microbial production of intracellular compounds can be engineered by redirecting the carbon flux towards products and increasing the cell size. Potential engineering strategies include exploiting clustered regularly interspaced short palindromic repeats interference (CRISPRi)-based tools for controlling gene expression. Here, we applied CRISPRi for engineering Acinetobacter baylyi ADP1, a model bacterium for synthesizing intracellular storage lipids, namely wax esters. We first established an inducible CRISPRi system for strain ADP1, which enables tightly controlled repression of target genes. We then targeted the glyoxylate shunt to redirect carbon flow towards wax esters. Second, we successfully employed CRISPRi for modifying cell morphology by repressing ftsZ, an essential gene required for cell division, in combination with targeted knock-outs to generate significantly enlarged filamentous or spherical cells respectively. The engineered cells sustained increased wax ester production metrics, demonstrating the potential of cell morphology engineering in the production of intracellular lipids.
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Affiliation(s)
- Jin Luo
- Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland
| | - Daniel Christoph Volke
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Ville Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland
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14
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Lin L, Capozzoli R, Ferrand A, Plum M, Vettiger A, Basler M. Subcellular localization of Type VI secretion system assembly in response to cell–cell contact. EMBO J 2022; 41:e108595. [PMID: 35634969 PMCID: PMC9251886 DOI: 10.15252/embj.2021108595] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 04/18/2022] [Accepted: 04/29/2022] [Indexed: 11/13/2022] Open
Abstract
Bacteria require a number of systems, including the type VI secretion system (T6SS), for interbacterial competition and pathogenesis. The T6SS is a large nanomachine that can deliver toxins directly across membranes of proximal target cells. Since major reassembly of T6SS is necessary after each secretion event, accurate timing and localization of T6SS assembly can lower the cost of protein translocation. Although critically important, mechanisms underlying spatiotemporal regulation of T6SS assembly remain poorly understood. Here, we used super‐resolution live‐cell imaging to show that while Acinetobacter and Burkholderia thailandensis can assemble T6SS at any site, a significant subset of T6SS assemblies localizes precisely to the site of contact between neighboring bacteria. We identified a class of diverse, previously uncharacterized, periplasmic proteins required for this dynamic localization of T6SS to cell–cell contact (TslA). This precise localization is also dependent on the outer membrane porin OmpA. Our analysis links transmembrane communication to accurate timing and localization of T6SS assembly as well as uncovers a pathway allowing bacterial cells to respond to cell–cell contact during interbacterial competition.
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Affiliation(s)
- Lin Lin
- Biozentrum University of Basel Basel Switzerland
| | | | - Alexia Ferrand
- Biozentrum Imaging Core Facility University of Basel Basel Switzerland
| | - Miro Plum
- Biozentrum University of Basel Basel Switzerland
| | | | - Marek Basler
- Biozentrum University of Basel Basel Switzerland
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15
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Perchat N, Dubois C, Mor-Gautier R, Duquesne S, Lechaplais C, Roche D, Fouteau S, Darii E, Perret A. Characterization of a novel β-alanine biosynthetic pathway consisting of promiscuous metabolic enzymes. J Biol Chem 2022; 298:102067. [PMID: 35623386 PMCID: PMC9213253 DOI: 10.1016/j.jbc.2022.102067] [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: 12/16/2021] [Revised: 05/19/2022] [Accepted: 05/22/2022] [Indexed: 10/28/2022] Open
Abstract
Bacteria adapt to utilize the nutrients available in their environment through a sophisticated metabolic system composed of highly specialized enzymes. Although these enzymes can metabolize molecules other than those for which they evolved, their efficiency toward promiscuous substrates is considered too low to be of physiological relevance. Herein, we investigated the possibility that these promiscuous enzymes are actually efficient enough at metabolizing secondary substrates to modify the phenotype of the cell. For example, in the bacterium Acinetobacter baylyi ADP1 (ADP1), panD (coding for l-aspartate decarboxylase) encodes the only protein known to catalyze the synthesis of β-alanine, an obligate intermediate in CoA synthesis. However, we show that the ADP1 ΔpanD mutant could also form this molecule through an unknown metabolic pathway arising from promiscuous enzymes and grow as efficiently as the wildtype strain. Using metabolomic analyses, we identified 1,3-diaminopropane and 3-aminopropanal as intermediates in this novel pathway. We also conducted activity screening and enzyme kinetics to elucidate candidate enzymes involved in this pathway, including 2,4-diaminobutyrate aminotransferase (Dat) and 2,4-diaminobutyrate decarboxylase (Ddc) and validated this pathway in vivo by analyzing the phenotype of mutant bacterial strains. Finally, we experimentally demonstrate that this novel metabolic route is not restricted to ADP1. We propose that the occurrence of conserved genes in hundreds of genomes across many phyla suggests that this previously undescribed pathway is widespread in prokaryotes.
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Affiliation(s)
- Nadia Perchat
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Christelle Dubois
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Rémi Mor-Gautier
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Sophie Duquesne
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Christophe Lechaplais
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - David Roche
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Stéphanie Fouteau
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Ekaterina Darii
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Alain Perret
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France.
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16
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The Impact of Natural Transformation on the Acquisition of Antibiotic Resistance Determinants. mBio 2022; 13:e0033622. [PMID: 35548953 PMCID: PMC9239042 DOI: 10.1128/mbio.00336-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Carbapenem and multidrug-resistant (MDR) Acinetobacter baumannii leads the World Health Organization's list of priority pathogens and represents an unmet medical need. Understanding the mechanisms underpinning the acquisition of antibiotic resistance in this pathogen is fundamental to the development of novel therapeutics as well as to infection prevention and antibiotic stewardship strategies designed to limit its spread. In their investigation, "Interbacterial Transfer of Carbapenem Resistance and Large Antibiotic Resistance Islands by Natural Transformation in Pathogenic Acinetobacter," Anne-Sophie Godeux and colleagues (mBio 13:e0263121, 2022, https://doi.org/10.1128/mBio.02631-21) delineate the unsuspected extent and circumstances under which natural transformation as a mechanism of intraspecies and interspecies exchange of genetic material occurs in Acinetobacter spp. This study offers key insights into how this notorious pathogen may have accelerated the development of its MDR phenotype via an unexpectedly robust and unnervingly casual approach to the acquisition of antibiotic resistance determinants through natural transformation.
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17
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Hogan AM, Cardona ST. Gradients in gene essentiality reshape antibacterial research. FEMS Microbiol Rev 2022; 46:fuac005. [PMID: 35104846 PMCID: PMC9075587 DOI: 10.1093/femsre/fuac005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 01/14/2022] [Accepted: 01/24/2022] [Indexed: 02/03/2023] Open
Abstract
Essential genes encode the processes that are necessary for life. Until recently, commonly applied binary classifications left no space between essential and non-essential genes. In this review, we frame bacterial gene essentiality in the context of genetic networks. We explore how the quantitative properties of gene essentiality are influenced by the nature of the encoded process, environmental conditions and genetic background, including a strain's distinct evolutionary history. The covered topics have important consequences for antibacterials, which inhibit essential processes. We argue that the quantitative properties of essentiality can thus be used to prioritize antibacterial cellular targets and desired spectrum of activity in specific infection settings. We summarize our points with a case study on the core essential genome of the cystic fibrosis pathobiome and highlight avenues for targeted antibacterial development.
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Affiliation(s)
- Andrew M Hogan
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Winnipeg, Manitoba R3T 2N2, Canada
| | - Silvia T Cardona
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Winnipeg, Manitoba R3T 2N2, Canada
- Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, University of Manitoba, Room 543 - 745 Bannatyne Avenue, Winnipeg, Manitoba, R3E 0J9, Canada
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18
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Arvay E, Biggs BW, Guerrero L, Jiang V, Tyo K. Engineering Acinetobacter baylyi ADP1 for mevalonate production from lignin-derived aromatic compounds. Metab Eng Commun 2021; 13:e00173. [PMID: 34430203 PMCID: PMC8367835 DOI: 10.1016/j.mec.2021.e00173] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 01/16/2023] Open
Abstract
Utilization of lignin, an abundant renewable resource, is limited by its heterogenous composition and complex structure. Biological valorization of lignin provides advantages over traditional chemical processing as it occurs at ambient temperature and pressure and does not use harsh chemicals. Furthermore, the ability to biologically funnel heterogenous substrates to products eliminates the need for costly downstream processing and separation of feedstocks. However, lack of relevant metabolic networks and low tolerance to degradation products of lignin limits the application of traditional engineered model organisms. To circumvent this obstacle, we employed Acinetobacter baylyi ADP1, which natively catabolizes lignin-derived aromatic substrates through the β-ketoadipate pathway, to produce mevalonate from lignin-derived compounds. We enabled expression of the mevalonate pathway in ADP1 and validated activity in the presence of multiple lignin-derived aromatic substrates. Furthermore, by knocking out wax ester synthesis and utilizing fed-batch cultivation, we improved mevalonate titers 7.5-fold to 1014 mg/L (6.8 mM). This work establishes a foundation and provides groundwork for future efforts to engineer improved production of mevalonate and derivatives from lignin-derived aromatics using ADP1. Acinetobacter baylyi ADP1 expresses the mevalonate pathway functionally Mevalonate is produced in the presence of multiple lignin-derived compounds Mevalonate is produced from solely lignin-derived aromatic carbon A wax ester knockout strain grown in fed-batch improves mevalonate titer 7.5-fold Lignin-derived compound fed-batch produces more mevalonate than glucose-fed
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Affiliation(s)
- Erika Arvay
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA.,Biotechnology Training Program, Northwestern University, Evanston, IL, USA
| | - Bradley W Biggs
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA.,Biotechnology Training Program, Northwestern University, Evanston, IL, USA
| | - Laura Guerrero
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Virginia Jiang
- Department of Chemical Engineering, Columbia University, New York, NY, USA
| | - Keith Tyo
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
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19
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Acinetobacter baylyi regulates type IV pilus synthesis by employing two extension motors and a motor protein inhibitor. Nat Commun 2021; 12:3744. [PMID: 34145281 PMCID: PMC8213720 DOI: 10.1038/s41467-021-24124-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 06/02/2021] [Indexed: 11/08/2022] Open
Abstract
Bacteria use extracellular appendages called type IV pili (T4P) for diverse behaviors including DNA uptake, surface sensing, virulence, protein secretion, and twitching motility. Dynamic extension and retraction of T4P is essential for their function, and T4P extension is thought to occur through the action of a single, highly conserved motor, PilB. Here, we develop Acinetobacter baylyi as a model to study T4P by employing a recently developed pilus labeling method. By contrast to previous studies of other bacterial species, we find that T4P synthesis in A. baylyi is dependent not only on PilB but also on an additional, phylogenetically distinct motor, TfpB. Furthermore, we identify a protein (CpiA) that inhibits T4P extension by specifically binding and inhibiting PilB but not TfpB. These results expand our understanding of T4P regulation and highlight how inhibitors might be exploited to disrupt T4P synthesis. Type IV pili (T4P) are retractile appendages used by bacteria for DNA uptake and other purposes. T4P extension is thought to occur through the action of a single motor protein, PilB. Here, Ellison et al. show that T4P synthesis in Acinetobacter baylyi depends not only on PilB but also on an additional, distinct motor, TfpB.
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20
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Acinetobacter baylyi ADP1-naturally competent for synthetic biology. Essays Biochem 2021; 65:309-318. [PMID: 33769448 DOI: 10.1042/ebc20200136] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 02/02/2023]
Abstract
Acinetobacter baylyi ADP1 is a non-pathogenic soil bacterium known for its metabolic diversity and high natural transformation and recombination efficiency. For these features, A. baylyi ADP1 has been long exploited in studying bacterial genetics and metabolism. The large pool of information generated in the fundamental studies has facilitated the development of a broad range of sophisticated and robust tools for the genome and metabolic engineering of ADP1. This mini-review outlines and describes the recent advances in ADP1 engineering and tool development, exploited in, for example, pathway and enzyme evolution, genome reduction and stabilization, and for the production of native and non-native products in both pure and rationally designed multispecies cultures. The rapidly expanding toolbox together with the unique features of A. baylyi ADP1 provide a strong base for a microbial cell factory excelling in synthetic biology applications where evolution meets rational engineering.
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21
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Messasma Z, Aggoun D, Houchi S, Ourari A, Ouennoughi Y, Keffous F, Mahdadi R. Biological activities, DFT calculations and docking of imines tetradentates ligands, derived from salicylaldehydic compounds as metallo-beta-lactamase inhibitors. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2020.129463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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22
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Kim M, Park J, Park W. Genomic and phenotypic analyses of multidrug-resistant Acinetobacter baumannii NCCP 16007 isolated from a patient with a urinary tract infection. Virulence 2020; 12:150-164. [PMID: 33372826 PMCID: PMC7781626 DOI: 10.1080/21505594.2020.1867421] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Polymyxin B (PMB) is increasingly used as a last-line antibiotic; however, the emergence of PMB resistance is a serious threat to global health. Here, a total of 40 Acinetobacter baumannii clinical isolates were collected to screen for PMB-resistant strains. Several clinical isolates including NCCP 16007 were far more resistant to PMB (MIC: 128-256 μg/ml) than the ATCC 17978 strain (MIC: 2 μg/ml) and appeared to possess resistance to broad-spectrum antibiotics including meropenem and 12 others. Four highly PMB-resistant strains possessed point mutations in the histidine kinase PmrB, leading to an increased expression of pmrC encoding a phosphoethanolamine transferase. Whole-genome analyses revealed that the NCCP 16007 stain had acquired two additional copies of the pmrC gene with phage integrase and 13 antibiotic resistance genes (ARGs) from other pathogens, including Klebsiella pneumoniae and Pseudomonas aeruginosa. The GC ratios of the ARGs (50-60%) were higher than that of the chromosomal backbone (39.06%), further supporting the horizontal gene transfer of ARGs. Comparative genomics with other multidrug-resistant A. baumannii strains revealed that the NCCP 16007 strain has many additional ARGs and has lost several virulence factors including Csu pili and heme oxygenase but exhibited high pathogenicity in Galleria mellonella-infection models. The observation of condensed biofilm through confocal and scanning electron microscopy suggested that the NCCP 16007 strain may possess high adhesion capacity during urinary tract infection. Therefore, our genomic and phenotypic analyses suggested that the multidrug-resistant A. baumannii NCCP 16007 strain possesses high genome plasticity, natural transformation ability, and pathogenicity.
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Affiliation(s)
- Misung Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University , Seoul, Republic of Korea
| | - Jaeeun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University , Seoul, Republic of Korea
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University , Seoul, Republic of Korea
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23
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Muir A, Gurung I, Cehovin A, Bazin A, Vallenet D, Pelicic V. Construction of a complete set of Neisseria meningitidis mutants and its use for the phenotypic profiling of this human pathogen. Nat Commun 2020; 11:5541. [PMID: 33139723 PMCID: PMC7606547 DOI: 10.1038/s41467-020-19347-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/05/2020] [Indexed: 01/29/2023] Open
Abstract
The bacterium Neisseria meningitidis causes life-threatening meningitis and sepsis. Here, we construct a complete collection of defined mutants in protein-coding genes of this organism, identifying all genes that are essential under laboratory conditions. The collection, named NeMeSys 2.0, consists of individual mutants in 1584 non-essential genes. We identify 391 essential genes, which are associated with basic functions such as expression and preservation of genome information, cell membrane structure and function, and metabolism. We use this collection to shed light on the functions of diverse genes, including a gene encoding a member of a previously unrecognised class of histidinol-phosphatases; a set of 20 genes required for type IV pili function; and several conditionally essential genes encoding antitoxins and/or immunity proteins. We expect that NeMeSys 2.0 will facilitate the phenotypic profiling of a major human bacterial pathogen.
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Affiliation(s)
- Alastair Muir
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Ishwori Gurung
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Ana Cehovin
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Adelme Bazin
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d'Evry, Université Paris-Saclay, CNRS, Evry, France
| | - David Vallenet
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d'Evry, Université Paris-Saclay, CNRS, Evry, France
| | - Vladimir Pelicic
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK.
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24
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Pardo I, Jha RK, Bermel RE, Bratti F, Gaddis M, McIntyre E, Michener W, Neidle EL, Dale T, Beckham GT, Johnson CW. Gene amplification, laboratory evolution, and biosensor screening reveal MucK as a terephthalic acid transporter in Acinetobacter baylyi ADP1. Metab Eng 2020; 62:260-274. [DOI: 10.1016/j.ymben.2020.09.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/11/2020] [Accepted: 09/19/2020] [Indexed: 12/19/2022]
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25
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Biggs BW, Bedore SR, Arvay E, Huang S, Subramanian H, McIntyre EA, Duscent-Maitland CV, Neidle EL, Tyo KEJ. Development of a genetic toolset for the highly engineerable and metabolically versatile Acinetobacter baylyi ADP1. Nucleic Acids Res 2020; 48:5169-5182. [PMID: 32246719 PMCID: PMC7229861 DOI: 10.1093/nar/gkaa167] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 02/20/2020] [Accepted: 03/04/2020] [Indexed: 01/10/2023] Open
Abstract
One primary objective of synthetic biology is to improve the sustainability of chemical manufacturing. Naturally occurring biological systems can utilize a variety of carbon sources, including waste streams that pose challenges to traditional chemical processing, such as lignin biomass, providing opportunity for remediation and valorization of these materials. Success, however, depends on identifying micro-organisms that are both metabolically versatile and engineerable. Identifying organisms with this combination of traits has been a historic hindrance. Here, we leverage the facile genetics of the metabolically versatile bacterium Acinetobacter baylyi ADP1 to create easy and rapid molecular cloning workflows, including a Cas9-based single-step marker-less and scar-less genomic integration method. In addition, we create a promoter library, ribosomal binding site (RBS) variants and test an unprecedented number of rationally integrated bacterial chromosomal protein expression sites and variants. At last, we demonstrate the utility of these tools by examining ADP1’s catabolic repression regulation, creating a strain with improved potential for lignin bioprocessing. Taken together, this work highlights ADP1 as an ideal host for a variety of sustainability and synthetic biology applications.
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Affiliation(s)
- Bradley W Biggs
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA.,Biotechnology Training Program, Northwestern University, Evanston, IL 60208, USA
| | - Stacy R Bedore
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Erika Arvay
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA.,Biotechnology Training Program, Northwestern University, Evanston, IL 60208, USA
| | - Shu Huang
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Harshith Subramanian
- Master of Science in Biotechnology Program, Northwestern University, Evanston, IL 60208, USA
| | - Emily A McIntyre
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | | | - Ellen L Neidle
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Keith E J Tyo
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
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26
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Grechko V, Podolsky D, Cheshchevik V. Identification new potential multidrug resistance proteins of Saccharomyces cerevisiae. J Microbiol Methods 2020; 176:106029. [DOI: 10.1016/j.mimet.2020.106029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 07/28/2020] [Accepted: 08/06/2020] [Indexed: 10/23/2022]
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27
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Wang Y, Lu J, Engelstädter J, Zhang S, Ding P, Mao L, Yuan Z, Bond PL, Guo J. Non-antibiotic pharmaceuticals enhance the transmission of exogenous antibiotic resistance genes through bacterial transformation. THE ISME JOURNAL 2020; 14:2179-2196. [PMID: 32424247 PMCID: PMC7367833 DOI: 10.1038/s41396-020-0679-2] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 05/04/2020] [Accepted: 05/05/2020] [Indexed: 12/19/2022]
Abstract
Antibiotic resistance is a serious global threat for public health. Considering the high abundance of cell-free DNA encoding antibiotic resistance genes (ARGs) in both clinical and environmental settings, natural transformation is an important horizontal gene transfer pathway to transmit antibiotic resistance. It is acknowledged that antibiotics are key drivers for disseminating antibiotic resistance, yet the contributions of non-antibiotic pharmaceuticals on transformation of ARGs are overlooked. In this study, we report that some commonly consumed non-antibiotic pharmaceuticals, at clinically and environmentally relevant concentrations, significantly facilitated the spread of antibiotic resistance through the uptake of exogenous ARGs. This included nonsteroidal anti-inflammatories, ibuprofen, naproxen, diclofenac, the lipid-lowering drug, gemfibrozil, and the β-blocker propranolol. Based on the results of flow cytometry, whole-genome RNA sequencing and proteomic analysis, the enhanced transformation of ARGs was affiliated with promoted bacterial competence, enhanced stress levels, over-produced reactive oxygen species and increased cell membrane permeability. In addition, a mathematical model was proposed and calibrated to predict the dynamics of transformation during exposure to non-antibiotic pharmaceuticals. Given the high consumption of non-antibiotic pharmaceuticals, these findings reveal new concerns regarding antibiotic resistance dissemination exacerbated by non-antibiotic pharmaceuticals.
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Affiliation(s)
- Yue Wang
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Ji Lu
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jan Engelstädter
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Shuai Zhang
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Pengbo Ding
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Likai Mao
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Philip L Bond
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jianhua Guo
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, 4072, Australia.
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28
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Suárez GA, Dugan KR, Renda BA, Leonard SP, Gangavarapu LS, Barrick JE. Rapid and assured genetic engineering methods applied to Acinetobacter baylyi ADP1 genome streamlining. Nucleic Acids Res 2020; 48:4585-4600. [PMID: 32232367 PMCID: PMC7192602 DOI: 10.1093/nar/gkaa204] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 03/15/2020] [Accepted: 03/18/2020] [Indexed: 01/10/2023] Open
Abstract
One goal of synthetic biology is to improve the efficiency and predictability of living cells by removing extraneous genes from their genomes. We demonstrate improved methods for engineering the genome of the metabolically versatile and naturally transformable bacterium Acinetobacter baylyi ADP1 and apply them to a genome streamlining project. In Golden Transformation, linear DNA fragments constructed by Golden Gate Assembly are directly added to cells to create targeted deletions, edits, or additions to the chromosome. We tested the dispensability of 55 regions of the ADP1 chromosome using Golden Transformation. The 18 successful multiple-gene deletions ranged in size from 21 to 183 kb and collectively accounted for 23.4% of its genome. The success of each multiple-gene deletion attempt could only be partially predicted on the basis of an existing collection of viable ADP1 single-gene deletion strains and a new transposon insertion sequencing (Tn-Seq) dataset that we generated. We further show that ADP1’s native CRISPR/Cas locus is active and can be retargeted using Golden Transformation. We reprogrammed it to create a CRISPR-Lock, which validates that a gene has been successfully removed from the chromosome and prevents it from being reacquired. These methods can be used together to implement combinatorial routes to further genome streamlining and for more rapid and assured metabolic engineering of this versatile chassis organism.
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Affiliation(s)
- Gabriel A Suárez
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Kyle R Dugan
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Brian A Renda
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Sean P Leonard
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Lakshmi Suryateja Gangavarapu
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Jeffrey E Barrick
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
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29
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Luo J, Efimova E, Losoi P, Santala V, Santala S. Wax ester production in nitrogen-rich conditions by metabolically engineered Acinetobacter baylyi ADP1. Metab Eng Commun 2020; 10:e00128. [PMID: 32477866 PMCID: PMC7251950 DOI: 10.1016/j.mec.2020.e00128] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 04/18/2020] [Accepted: 04/19/2020] [Indexed: 11/29/2022] Open
Abstract
Metabolic engineering can be used as a powerful tool to redirect cell resources towards product synthesis, also in conditions that are not optimal for the production. An example of synthesis strongly dependent on external conditions is the production of storage lipids, which typically requires a high carbon/nitrogen ratio. This requirement also limits the use of abundant nitrogen-rich materials, such as industrial protein by-products, as substrates for lipid production. Acinetobacter baylyi ADP1 is known for its ability to produce industrially interesting storage lipids, namely wax esters (WEs). Here, we engineered A. baylyi ADP1 by deleting the gene aceA encoding for isocitrate lyase and overexpressing fatty acyl-CoA reductase Acr1 in the wax ester production pathway to allow redirection of carbon towards WEs. This strategy led to 3-fold improvement in yield (0.075 g/g glucose) and 3.15-fold improvement in titer (1.82 g/L) and productivity (0.038 g/L/h) by a simple one-stage batch cultivation with glucose as carbon source. The engineered strain accumulated up to 27% WEs of cell dry weight. The titer and cellular WE content are the highest reported to date among microbes. We further showed that the engineering strategy alleviated the inherent requirement for high carbon/nitrogen ratio and demonstrated the production of wax esters using nitrogen-rich substrates including casamino acids, yeast extract, and baker's yeast hydrolysate, which support biomass production but not WE production in wild-type cells. The study demonstrates the power of metabolic engineering in overcoming natural limitations in the production of storage lipids.
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Affiliation(s)
- Jin Luo
- Faculty of Engineering and Natural Sciences, Hervanta Campus, Tampere University, Korkeakoulunkatu 8, Tampere, 33720, Finland
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Hervanta Campus, Tampere University, Korkeakoulunkatu 8, Tampere, 33720, Finland
| | - Pauli Losoi
- Faculty of Engineering and Natural Sciences, Hervanta Campus, Tampere University, Korkeakoulunkatu 8, Tampere, 33720, Finland
| | - Ville Santala
- Faculty of Engineering and Natural Sciences, Hervanta Campus, Tampere University, Korkeakoulunkatu 8, Tampere, 33720, Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Hervanta Campus, Tampere University, Korkeakoulunkatu 8, Tampere, 33720, Finland
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30
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Veress A, Nagy T, Wilk T, Kömüves J, Olasz F, Kiss J. Abundance of mobile genetic elements in an Acinetobacter lwoffii strain isolated from Transylvanian honey sample. Sci Rep 2020; 10:2969. [PMID: 32076091 PMCID: PMC7031236 DOI: 10.1038/s41598-020-59938-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 02/03/2020] [Indexed: 11/15/2022] Open
Abstract
Based on phylogenetic analyses, strain M2a isolated from honey, an unexpected source of acinetobacters, was classified as Acinetobacter lwoffii. The genome of this strain is strikingly crowded with mobile genetic elements. It harbours more than 250 IS elements of 15 IS-families, several unit and compound transposons and 15 different plasmids. These IS elements, including 30 newly identified ones, could be classified into at least 53 IS species. Regarding the plasmids, 13 of the 15 belong to the Rep-3 superfamily and only one plasmid, belonging to the “Low-GC” family, possesses a seemingly complete conjugative system. The other plasmids, with one exception, have a mobilization region of common pattern, consisting of the divergent mobA/mobL-family and mobS-, mobC- or traD-like genes separated by an oriT-like sequence. Although two plasmids of M2a are almost identical to those of A. lwoffi strains isolated from gold mine or Pleistocene sediments, most of them have no close relatives. The presence of numerous plasmid-borne and chromosomal metal resistance determinants suggests that M2a previously has also evolved in a metal-polluted environment. The numerous, possibly transferable, plasmids and the outstanding number of transposable elements may reflect the high potential of M2a for rapid evolution.
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Affiliation(s)
- Alexandra Veress
- Department of Genetics, Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, Gödöllő, H-2100, Hungary
| | - Tibor Nagy
- Department of Genetics, Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, Gödöllő, H-2100, Hungary
| | - Tímea Wilk
- Department of Genetics, Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, Gödöllő, H-2100, Hungary
| | - János Kömüves
- Department of Genetics, Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, Gödöllő, H-2100, Hungary
| | - Ferenc Olasz
- Department of Genetics, Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, Gödöllő, H-2100, Hungary
| | - János Kiss
- Department of Genetics, Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, Gödöllő, H-2100, Hungary.
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31
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Furuichi Y, Yoshimoto S, Inaba T, Nomura N, Hori K. Process Description of an Unconventional Biofilm Formation by Bacterial Cells Autoagglutinating through Sticky, Long, and Peritrichate Nanofibers. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2520-2529. [PMID: 31972092 DOI: 10.1021/acs.est.9b06577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this study, we elucidated the formation process of an unconventional biofilm formed by a bacterium autoagglutinating through sticky, long, and peritrichate nanofibers. Understanding the mechanisms of biofilm formation is essential to control microbial behavior and improve environmental biotechnologies. Acinetobacter sp. Tol 5 autoagglutinate through the interaction of the long, peritrichate nanofiber protein AtaA, a trimeric autotransporter adhesin. Using AtaA, without cell growth or extracellular polymeric substances production, Tol 5 cells quickly form an unconventional biofilm. The process forming this unconventional biofilm started with cell-cell interactions, proceeded to cell clumping, and led to the formation of large cell aggregates. The cell-cell interaction was described by Derjaguin-Landau-Verwey-Overbeek (DLVO) theory based on a new concept, which considers two independent interactions between two cell bodies and between two AtaA fiber tips forming a discontinuous surface. If cell bodies cannot collide owing to an energy barrier at low ionic strengths but approach within the interactive distance of AtaA fibers, cells can agglutinate through their contact. Cell clumping proceeds following the cluster-cluster aggregation model, and an unconventional biofilm containing void spaces and a fractal nature develops. Understanding its formation process would extend the utilization of various types of biofilms, enhancing environmental biotechnologies.
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Affiliation(s)
- Yoshihide Furuichi
- Department of Biotechnology, Graduate School of Engineering , Nagoya University , Furo-cho, Chikusa-ku , Nagoya , Aichi 464-8603 , Japan
| | - Shogo Yoshimoto
- Department of Biomolecular Engineering, Graduate School of Engineering , Nagoya University , Furo-cho, Chikusa-ku , Nagoya , Aichi 464-8603 , Japan
| | - Tomohiro Inaba
- Graduate School of Life and Environmental Sciences , University of Tsukuba , Tsukuba , Ibaraki 305-0006 , Japan
| | - Nobuhiko Nomura
- Faculty of Life and Environmental Sciences , University of Tsukuba , Tsukuba , Ibaraki 305-0006 , Japan
- Microbiology Research Center for Sustainability , University of Tsukuba , Tsukuba , Ibaraki 305-8572 , Japan
| | - Katsutoshi Hori
- Department of Biomolecular Engineering, Graduate School of Engineering , Nagoya University , Furo-cho, Chikusa-ku , Nagoya , Aichi 464-8603 , Japan
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32
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Jiang B, Xing Y, Li G, Zhang N, Lian L, Sun G, Zhang D. iTRAQ-Based Comparative Proteomic Analysis of Acinetobacter baylyi ADP1 Under DNA Damage in Relation to Different Carbon Sources. Front Microbiol 2020; 10:2906. [PMID: 31993023 PMCID: PMC6971185 DOI: 10.3389/fmicb.2019.02906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 12/02/2019] [Indexed: 12/27/2022] Open
Abstract
DNA damage response allows microorganisms to repair or bypass DNA damage and maintain the genome integrity. It has attracted increasing attention but the underlying influential factors affecting DNA damage response are still unclear. In this work, isobaric tags for relative and absolute quantification (iTRAQ)-based proteomic analysis was used to investigate the influence of carbon sources on the translational response of Acinetobacter baylyi ADP1 to DNA damage. After cultivating in a nutrient-rich medium (LB) and defined media supplemented with four different carbon sources (acetate, citrate, pyruvate, and succinate), a total of 2807 proteins were identified. Among them, 84 proteins involved in stress response were significantly altered, indicating the strong influence of carbon source on the response of A. baylyi ADP1 to DNA damage and other stresses. As the first study on the comparative global proteomic changes in A. baylyi ADP1 under DNA damage across nutritional environments, our findings revealed that DNA damage response in A. baylyi ADP1 at the translational level is significantly altered by carbon source, providing an insight into the complex protein interactions across carbon sources and offering theoretical clues for further study to elucidate their general regulatory mechanism to adapt to different nutrient environments.
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Affiliation(s)
- Bo Jiang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China.,Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Yi Xing
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China.,Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Guanghe Li
- School of Environment, Tsinghua University, Beijing, China.,State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, China
| | - Nana Zhang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China.,Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Luning Lian
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, China.,Beijing Key Laboratory of Resource-Oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Guangdong Sun
- School of Environment, Tsinghua University, Beijing, China.,State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, China
| | - Dayi Zhang
- School of Environment, Tsinghua University, Beijing, China.,State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, China
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33
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Lin L, Ringel PD, Vettiger A, Dürr L, Basler M. DNA Uptake upon T6SS-Dependent Prey Cell Lysis Induces SOS Response and Reduces Fitness of Acinetobacter baylyi. Cell Rep 2019; 29:1633-1644.e4. [DOI: 10.1016/j.celrep.2019.09.083] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 08/23/2019] [Accepted: 09/27/2019] [Indexed: 11/29/2022] Open
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34
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Nero TM, Dalia TN, Wang JCY, Kysela DT, Bochman ML, Dalia AB. ComM is a hexameric helicase that promotes branch migration during natural transformation in diverse Gram-negative species. Nucleic Acids Res 2019; 46:6099-6111. [PMID: 29722872 PMCID: PMC6158740 DOI: 10.1093/nar/gky343] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 04/19/2018] [Indexed: 12/16/2022] Open
Abstract
Acquisition of foreign DNA by natural transformation is an important mechanism of adaptation and evolution in diverse microbial species. Here, we characterize the mechanism of ComM, a broadly conserved AAA+ protein previously implicated in homologous recombination of transforming DNA (tDNA) in naturally competent Gram-negative bacterial species. In vivo, we found that ComM was required for efficient comigration of linked genetic markers in Vibrio cholerae and Acinetobacter baylyi, which is consistent with a role in branch migration. Also, ComM was particularly important for integration of tDNA with increased sequence heterology, suggesting that its activity promotes the acquisition of novel DNA sequences. In vitro, we showed that purified ComM binds ssDNA, oligomerizes into a hexameric ring, and has bidirectional helicase and branch migration activity. Based on these data, we propose a model for tDNA integration during natural transformation. This study provides mechanistic insight into the enigmatic steps involved in tDNA integration and uncovers the function of a protein required for this conserved mechanism of horizontal gene transfer.
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Affiliation(s)
- Thomas M Nero
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Triana N Dalia
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | | | - David T Kysela
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Matthew L Bochman
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN 47405, USA
| | - Ankur B Dalia
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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35
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Abstract
The genomes of Acinetobacter baumannii tell us stories about horizontal gene transfer (HGT) events that steadily drive the evolution of this nosocomial pathogen toward multidrug resistance. Natural transformation competence constitutes one of the several possible pathways that mediate HGT in A. baumannii. Here, we describe and discuss the methods for studying DNA uptake in A. baumannii via natural transformation.
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36
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Essential gene deletions producing gigantic bacteria. PLoS Genet 2019; 15:e1008195. [PMID: 31181062 PMCID: PMC6586353 DOI: 10.1371/journal.pgen.1008195] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/20/2019] [Accepted: 05/14/2019] [Indexed: 01/01/2023] Open
Abstract
To characterize the consequences of eliminating essential functions needed for peptidoglycan synthesis, we generated deletion mutations of Acinetobacter baylyi by natural transformation and visualized the resulting microcolonies of dead cells. We found that loss of genes required for peptidoglycan precursor synthesis or polymerization led to the formation of polymorphic giant cells with diameters that could exceed ten times normal. Treatment with antibiotics targeting early or late steps of peptidoglycan synthesis also produced giant cells. The giant cells eventually lysed, although they were partially stabilized by osmotic protection. Genome-scale transposon mutant screening (Tn-seq) identified mutations that blocked or accelerated giant cell formation. Among the mutations that blocked the process were those inactivating a function predicted to cleave murein glycan chains (the MltD murein lytic transglycosylase), suggesting that giant cell formation requires MltD hydrolysis of existing peptidoglycan. Among the mutations that accelerated giant cell formation after ß-lactam treatment were those inactivating an enzyme that produces unusual 3->3 peptide cross-links in peptidoglycan (the LdtG L,D-transpeptidase). The mutations may weaken the sacculus and make it more vulnerable to further disruption. Although the study focused on A. baylyi, we found that a pathogenic relative (A. baumannii) also produced giant cells with genetic dependencies overlapping those of A. baylyi. Overall, the analysis defines a genetic pathway for giant cell formation conserved in Acinetobacter species in which independent initiating branches converge to create the unusual cells. Although essential genes control the most basic functions of bacterial life, they are difficult to study genetically because mutants lacking the functions die. We have developed a simple procedure for creating bacteria in which different essential genes have been completely deleted, making it possible to analyze the roles of the missing functions based on the features of the dead cells that result. When genes needed for the production of the cell wall were inactivated, the bacteria formed bizarre giant cells. It was possible to identify the functions responsible for forming the giant cells, and to formulate a model for how they form. Since cell wall synthesis is one of the most important antibiotic targets, understanding how bacteria respond to its disruption may ultimately help in developing procedures to overcome antibiotic resistant bacterial infections.
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Acinetobacter baylyi ADP1 growth performance and lipid accumulation on different carbon sources. Appl Microbiol Biotechnol 2019; 103:6217-6229. [DOI: 10.1007/s00253-019-09910-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 05/03/2019] [Accepted: 05/09/2019] [Indexed: 12/11/2022]
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Salmela M, Lehtinen T, Efimova E, Santala S, Santala V. Alkane and wax ester production from lignin‐related aromatic compounds. Biotechnol Bioeng 2019; 116:1934-1945. [DOI: 10.1002/bit.27005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/29/2019] [Accepted: 04/18/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Milla Salmela
- Faculty of Engineering and Natural Sciences, Hervanta CampusTampere UniversityTampere Finland
| | - Tapio Lehtinen
- Faculty of Engineering and Natural Sciences, Hervanta CampusTampere UniversityTampere Finland
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Hervanta CampusTampere UniversityTampere Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Hervanta CampusTampere UniversityTampere Finland
| | - Ville Santala
- Faculty of Engineering and Natural Sciences, Hervanta CampusTampere UniversityTampere Finland
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Fariba Akrami, Amirmorteza Ebrahimzadeh Namvar. Acinetobacter baumannii as Nosocomial Pathogenic Bacteria. MOLECULAR GENETICS, MICROBIOLOGY AND VIROLOGY 2019. [DOI: 10.3103/s0891416819020046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Geng P, Leonard SP, Mishler DM, Barrick JE. Synthetic Genome Defenses against Selfish DNA Elements Stabilize Engineered Bacteria against Evolutionary Failure. ACS Synth Biol 2019; 8:521-531. [PMID: 30703321 DOI: 10.1021/acssynbio.8b00426] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Mobile genetic elements drive evolution by disrupting genes and rearranging genomes. Eukaryotes have evolved epigenetic mechanisms, including DNA methylation and RNA interference, that silence mobile elements and thereby preserve the integrity of their genomes. We created an artificial reprogrammable epigenetic system based on CRISPR interference to give engineered bacteria a similar line of defense against transposons and other selfish elements in their genomes. We demonstrate that this CRISPR interference against mobile elements (CRISPRi-ME) approach can be used to simultaneously repress two different transposon families in Escherichia coli, thereby increasing the evolutionary stability of costly protein expression. We further show that silencing a transposon in Acinetobacter baylyi ADP1 reduces mutation rates by a factor of 5, nearly as much as deleting all copies of this element from its genome. By deploying CRISPRi-ME on a broad-host-range vector, we have created a generalizable platform for stabilizing the genomes of engineered bacterial cells for applications in metabolic engineering and synthetic biology.
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Affiliation(s)
- Peng Geng
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Sean P. Leonard
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Dennis M. Mishler
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jeffrey E. Barrick
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, United States
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Thomas M, Stuani L, Darii E, Lechaplais C, Pateau E, Tabet JC, Salanoubat M, Saaidi PL, Perret A. De novo structure determination of 3-((3-aminopropyl)amino)-4-hydroxybenzoic acid, a novel and abundant metabolite in Acinetobacter baylyi ADP1. Metabolomics 2019; 15:45. [PMID: 30874951 DOI: 10.1007/s11306-019-1508-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 03/07/2019] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Metabolite identification remains a major bottleneck in the understanding of metabolism. Many metabolomics studies end up with unknown compounds, leaving a landscape of metabolites and metabolic pathways to be unraveled. Therefore, identifying novel compounds within a metabolome is an entry point into the 'dark side' of metabolism. OBJECTIVES This work aimed at elucidating the structure of a novel metabolite that was first detected in the soil bacterium Acinetobacter baylyi ADP1 (ADP1). METHODS We used high resolution multi-stage tandem mass spectrometry for characterizing the metabolite within the metabolome. We purified the molecule for 1D- and 2D-NMR (1H, 13C, 1H-1H-COSY, 1H-13C-HSQC, 1H-13C-HMBC and 1H-15N-HMBC) analyses. Synthetic standards were chemically prepared from MS and NMR data interpretation. RESULTS We determined the de novo structure of a previously unreported metabolite: 3-((3-aminopropyl)amino)-4-hydroxybenzoic acid. The proposed structure was validated by comparison to a synthetic standard. With a concentration in the millimolar range, this compound appears as a major metabolite in ADP1, which we anticipate to participate to an unsuspected metabolic pathway. This novel metabolite was also detected in another γ-proteobacterium. CONCLUSION Structure elucidation of this abundant and novel metabolite in ADP1 urges to decipher its biosynthetic pathway and cellular function.
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Affiliation(s)
- Marion Thomas
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
| | - Lucille Stuani
- INSERM, Institut National de la Santé et de la Recherche Médicale - CNRS - UPS - Centre de Recherche en Cancérologie de Toulouse (CRCT), Toulouse, France
| | - Ekaterina Darii
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
| | - Christophe Lechaplais
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
| | - Emilie Pateau
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
| | - Jean-Claude Tabet
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Institut Parisien de Chimie Moléculaire, Paris, France
- CEA, iBiTec-S, SPI, LEMM, Gif-sur-Yvette, France
| | - Marcel Salanoubat
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France
| | - Pierre-Loïc Saaidi
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France.
| | - Alain Perret
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057, Evry, France.
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Synthetic metabolic pathway for the production of 1-alkenes from lignin-derived molecules. Microb Cell Fact 2019; 18:48. [PMID: 30857542 PMCID: PMC6410514 DOI: 10.1186/s12934-019-1097-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 02/28/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Integration of synthetic metabolic pathways to catabolically diverse chassis provides new opportunities for sustainable production. One attractive scenario is the use of abundant waste material to produce a readily collectable product, which can reduce the production costs. Towards that end, we established a cellular platform for the production of semivolatile medium-chain α-olefins from lignin-derived molecules: we constructed 1-undecene synthesis pathway in Acinetobacter baylyi ADP1 using ferulate, a lignin-derived model compound, as the sole carbon source for both cell growth and product synthesis. RESULTS In order to overcome the toxicity of ferulate, we first applied adaptive laboratory evolution to A. baylyi ADP1, resulting in a highly ferulate-tolerant strain. The adapted strain exhibited robust growth in 100 mM ferulate while the growth of the wild type strain was completely inhibited. Next, we expressed two heterologous enzymes in the wild type strain to confer 1-undecene production from glucose: a fatty acid decarboxylase UndA from Pseudomonas putida, and a thioesterase 'TesA from Escherichia coli. Finally, we constructed the 1-undecene synthesis pathway in the ferulate-tolerant strain. The engineered cells were able to produce biomass and 1-undecene solely from ferulate, and excreted the product directly to the culture headspace. CONCLUSIONS In this study, we employed a bacterium Acinetobacter baylyi ADP1 to integrate a natural aromatics degrading pathway to a synthetic production route, allowing the upgradation of lignin derived molecules to value-added products. We developed a highly ferulate-tolerant strain and established the biosynthesis of an industrially relevant chemical, 1-undecene, solely from the lignin-derived model compound. This study reports the production of alkenes from lignin derived molecules for the first time and demonstrates the potential of lignin as a sustainable resource in the bio-based synthesis of valuable products.
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Conte E, Mende L, Grainge I, Colloms SD. A Mini-ISY100 Transposon Delivery System Effective in γ Proteobacteria. Front Microbiol 2019; 10:280. [PMID: 30873132 PMCID: PMC6400869 DOI: 10.3389/fmicb.2019.00280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 02/04/2019] [Indexed: 11/17/2022] Open
Abstract
Transposons are invaluable biological tools for the genetic manipulation of microorganisms. ISY100 from Synechocystis sp. PCC6803 is a member of the Tc1/mariner/IS630 superfamily, and is characterized by high transposition efficiency and a strong preference for TA target sequences. In this paper, we describe the design and application of a mini-ISY100 suicide vector for the in vivo creation of stable random transposon insertion libraries. The system was successfully applied in seven species belonging to four different orders of γ proteobacteria. In all cases, delivery using conjugation consistently showed the highest transposition efficiency compared to chemical transformation or electroporation. We determined the frequency of transposon insertions in all the species and proved the utility of the system by identifying genes involved in colony coloration in Shewanella oneidensis. The ease and the efficiency of the protocol developed here allow the creation of complete knock-out libraries in an extensive range of host microorganisms in less than a week with no requirement for preparatory modification.
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Affiliation(s)
- Emanuele Conte
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Linda Mende
- School of Environmental and Life Sciences, University of Newcastle, Newcastle, NSW, Australia
| | - Ian Grainge
- School of Environmental and Life Sciences, University of Newcastle, Newcastle, NSW, Australia
| | - Sean D Colloms
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
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Efficient Counterselection for Methylococcus capsulatus (Bath) by Using a Mutated pheS Gene. Appl Environ Microbiol 2018; 84:AEM.01875-18. [PMID: 30266726 DOI: 10.1128/aem.01875-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/22/2018] [Indexed: 11/20/2022] Open
Abstract
Methylococcus capsulatus (Bath) is a representative gammaproteobacterial methanotroph that has been studied extensively in diverse research fields. The sacB gene, which encodes levansucrase, causing cell death in the presence of sucrose, is widely used as a counterselectable marker for disruption of a target gene in Gram-negative bacteria. However, sacB is not applicable to all Gram-negative bacteria, and its efficiency for the counterselection of M. capsulatus (Bath) is low. Here, we report the construction of an alternative counterselectable marker, pheS*, by introduction of two point mutations (A306G and T252A) into the pheS gene from M. capsulatus (Bath), which encodes the α-subunit of phenylalanyl-tRNA synthetase. The transformant harboring pheS* on an expression plasmid showed sensitivity to 10 mM p-chloro-phenylalanine, whereas the transformant harboring an empty plasmid showed no sensitivity, indicating the availability of pheS* as a counterselectable marker in M. capsulatus (Bath). To validate the utility of the pheS* marker in counterselection, we attempted to obtain an unmarked mutant of xoxF, a gene encoding the major subunit of Xox methanol dehydrogenase, which we failed to obtain by counterselection using the sacB marker. PCR, immunodetection using an anti-XoxF antiserum, and a cell growth assay in the absence of calcium demonstrated successful disruption of the xoxF gene in M. capsulatus (Bath). The difference in counterselection efficiencies of the markers indicated that pheS* is more suitable than sacB for counterselection in M. capsulatus (Bath). This study provides a new genetic tool enabling efficient counterselection in M. capsulatus (Bath).IMPORTANCE Methanotrophs have long been considered promising strains for biologically reducing methane from the environment and converting it into valuable products, because they can oxidize methane at ambient temperatures and pressures. Although several methodologies and tools for the genetic manipulation of methanotrophs have been developed, their mutagenic efficiency remains lower than that of tractable strains such as Escherichia coli Therefore, further improvements are still desired. The significance of our study is that we increased the efficiency of counterselection in M. capsulatus (Bath) by employing pheS*, which was newly constructed as a counterselectable marker. This will allow for the efficient production of gene-disrupted and gene-integrated mutants of M. capsulatus (Bath). We anticipate that this counterselection system will be utilized widely by the methanotroph research community, leading to improved productivity of methane-based bioproduction and new insights into methanotrophy.
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Contact-Dependent Growth Inhibition Proteins in Acinetobacter baylyi ADP1. Curr Microbiol 2018; 75:1434-1440. [PMID: 30019131 PMCID: PMC6182759 DOI: 10.1007/s00284-018-1540-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 07/12/2018] [Indexed: 02/08/2023]
Abstract
Bacterial contact-dependent growth inhibition (CDI) systems are two-partner secretion systems in which toxic CdiA proteins are exported on the outer membrane by cognate transporter CdiB proteins. Upon binding to specific receptors, the C-terminal toxic (CT) domain, detached from CdiA, is delivered to neighbouring cells. Contacts inhibit the growth of not-self-bacteria, lacking immunity proteins co-expressed with CdiA, but promote cooperative behaviours in "self" bacteria, favouring the formation of biofilm structures. The Acinetobacter baylyi ADP1 strain features two CdiA, which differ significantly in size and have different CT domains. Homologous proteins sharing the same CT domains have been identified in A. baumannii. The growth inhibition property of the two A. baylyi CdiA proteins was supported by competition assays between wild-type cells and mutants lacking immunity genes. However, neither protein plays a role in biofilm formation or adherence to epithelial cells, as proved by assays carried out with knockout mutants. Inhibitory and stimulatory properties may be similarly uncoupled in A. baumannii proteins.
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Pezo V, Hassan C, Louis D, Sargueil B, Herdewijn P, Marlière P. Metabolic Recruitment and Directed Evolution of Nucleoside Triphosphate Uptake in Escherichia coli. ACS Synth Biol 2018; 7:1565-1572. [PMID: 29746092 DOI: 10.1021/acssynbio.8b00048] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the design and elaboration of a selection protocol for importing a canonical substrate of DNA polymerase, thymidine triphosphate (dTTP) in Escherichia coli. Bacterial strains whose growth depend on dTTP uptake, through the action of an algal plastid transporter expressed from a synthetic gene inserted in the chromosome, were constructed and shown to withstand the simultaneous loss of thymidylate synthase and thymidine kinase. Such thyA tdk dual deletant strains provide an experimental model of tight nutritional containment for preventing dissemination of microbial GMOs. Our strains transported the four canonical dNTPs, in the following order of preference: dCTP > dATP ≥ dGTP > dTTP. Prolonged cultivation under limitation of exogenous dTTP led to the enhancement of dNTP transport by adaptive evolution. We investigated the uptake of dCTP analogues with altered sugar or nucleobase moieties, which were found to cause a loss of cell viability and an increase of mutant frequency, respectively. E. coli strains equipped with nucleoside triphosphate transporters should be instrumental for evolving organisms whose DNA genome is morphed chemically by fully substituting its canonical nucleotide components.
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Affiliation(s)
- Valérie Pezo
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057 Evry, France
- ISSB, Génopole, 5 rue Henri Desbruères, 91000 Evry, France
| | | | | | - Bruno Sargueil
- CNRS UMR 8015, Laboratoire de Cristallographie et RMN Biologiques, Université Paris Descartes, 4 avenue de l’Observatoire, 75006 Paris, France
| | - Piet Herdewijn
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057 Evry, France
- ISSB, Génopole, 5 rue Henri Desbruères, 91000 Evry, France
| | - Philippe Marlière
- ISSB, Génopole, 5 rue Henri Desbruères, 91000 Evry, France
- TESSSI, 81 rue Réaumur, 75002 Paris, France
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Cell behavior of the highly sticky bacterium Acinetobacter sp. Tol 5 during adhesion in laminar flows. Sci Rep 2018; 8:8285. [PMID: 29844614 PMCID: PMC5974025 DOI: 10.1038/s41598-018-26699-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/11/2018] [Indexed: 12/17/2022] Open
Abstract
It is important to characterize how medically, industrially, or environmentally important bacteria adhere to surfaces in liquid flows in order to control their cell adhesion and subsequent biofilm formation. Acinetobacter sp. Tol 5 is a remarkably sticky bacterium that autoagglutinates through the adhesive nanofiber protein AtaA, which is applicable to cell immobilization in bioprocesses. In this study, the adhesion and behavior of Tol 5 cells in laminar flows were investigated using flow cell systems. Tol 5 cells autoagglutinated through AtaA and formed cell clumps during flowing. The cell clumps rather than single cells went downward due to gravity and adhered to the bottom surface. Under appropriate shear stress, a twin vortex was caused by a separated flow generated at the rear of the pre-immobilized cell clumps and carried the small cell clumps to this location, resulting in their stacking there. The rearward immobilized cell clumps developed into a large, stable aggregate with a streamlined shape, independent of cell growth. Cell clumps hardly ever developed under weak shear stress that could not generate a twin vortex and were broken up under excessively strong shear stress. These cell behaviors including the importance of clumping are interesting features in the bacterial adhesion processes.
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Freed E, Fenster J, Smolinski SL, Walker J, Henard CA, Gill R, Eckert CA. Building a genome engineering toolbox in nonmodel prokaryotic microbes. Biotechnol Bioeng 2018; 115:2120-2138. [PMID: 29750332 DOI: 10.1002/bit.26727] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/02/2018] [Accepted: 03/10/2018] [Indexed: 12/26/2022]
Abstract
The realization of a sustainable bioeconomy requires our ability to understand and engineer complex design principles for the development of platform organisms capable of efficient conversion of cheap and sustainable feedstocks (e.g., sunlight, CO2 , and nonfood biomass) into biofuels and bioproducts at sufficient titers and costs. For model microbes, such as Escherichia coli, advances in DNA reading and writing technologies are driving the adoption of new paradigms for engineering biological systems. Unfortunately, microbes with properties of interest for the utilization of cheap and renewable feedstocks, such as photosynthesis, autotrophic growth, and cellulose degradation, have very few, if any, genetic tools for metabolic engineering. Therefore, it is important to develop "design rules" for building a genetic toolbox for novel microbes. Here, we present an overview of our current understanding of these rules for the genetic manipulation of prokaryotic microbes and the available genetic tools to expand our ability to genetically engineer nonmodel systems.
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Affiliation(s)
- Emily Freed
- National Renewable Energy Laboratory, Biosciences Center, Golden, CO.,Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO
| | - Jacob Fenster
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO.,Chemical and Biological Engineering, University of Colorado, Boulder, CO
| | | | - Julie Walker
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO
| | - Calvin A Henard
- National Renewable Energy Laboratory, National Bioenergy Center, Golden, CO
| | - Ryan Gill
- National Renewable Energy Laboratory, Biosciences Center, Golden, CO.,Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO.,Chemical and Biological Engineering, University of Colorado, Boulder, CO
| | - Carrie A Eckert
- National Renewable Energy Laboratory, Biosciences Center, Golden, CO.,Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO
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Cell-based screen for discovering lipopolysaccharide biogenesis inhibitors. Proc Natl Acad Sci U S A 2018; 115:6834-6839. [PMID: 29735709 DOI: 10.1073/pnas.1804670115] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
New drugs are needed to treat gram-negative bacterial infections. These bacteria are protected by an outer membrane which prevents many antibiotics from reaching their cellular targets. The outer leaflet of the outer membrane contains LPS, which is responsible for creating this permeability barrier. Interfering with LPS biogenesis affects bacterial viability. We developed a cell-based screen that identifies inhibitors of LPS biosynthesis and transport by exploiting the nonessentiality of this pathway in Acinetobacter We used this screen to find an inhibitor of MsbA, an ATP-dependent flippase that translocates LPS across the inner membrane. Treatment with the inhibitor caused mislocalization of LPS to the cell interior. The discovery of an MsbA inhibitor, which is universally conserved in all gram-negative bacteria, validates MsbA as an antibacterial target. Because our cell-based screen reports on the function of the entire LPS biogenesis pathway, it could be used to identify compounds that inhibit other targets in the pathway, which can provide insights into vulnerabilities of the gram-negative cell envelope.
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Elucidation of the trigonelline degradation pathway reveals previously undescribed enzymes and metabolites. Proc Natl Acad Sci U S A 2018; 115:E4358-E4367. [PMID: 29686076 DOI: 10.1073/pnas.1722368115] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Trigonelline (TG; N-methylnicotinate) is a ubiquitous osmolyte. Although it is known that it can be degraded, the enzymes and metabolites have not been described so far. In this work, we challenged the laboratory model soil-borne, gram-negative bacterium Acinetobacter baylyi ADP1 (ADP1) for its ability to grow on TG and we identified a cluster of catabolic, transporter, and regulatory genes. We dissected the pathway to the level of enzymes and metabolites, and proceeded to in vitro reconstruction of the complete pathway by six purified proteins. The four enzymatic steps that lead from TG to methylamine and succinate are described, and the structures of previously undescribed metabolites are provided. Unlike many aromatic compounds that undergo hydroxylation prior to ring cleavage, the first step of TG catabolism proceeds through direct cleavage of the C5-C6 bound, catalyzed by a flavin-dependent, two-component oxygenase, which yields (Z)-2-((N-methylformamido)methylene)-5-hydroxy-butyrolactone (MFMB). MFMB is then oxidized into (E)-2-((N-methylformamido) methylene) succinate (MFMS), which is split up by a hydrolase into carbon dioxide, methylamine, formic acid, and succinate semialdehyde (SSA). SSA eventually fuels up the TCA by means of an SSA dehydrogenase, assisted by a Conserved Hypothetical Protein. The cluster is conserved across marine, soil, and plant-associated bacteria. This emphasizes the role of TG as a ubiquitous nutrient for which an efficient microbial catabolic toolbox is available.
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