1
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Cheng C, Su S, Bo S, Zheng C, Liu C, Zhang L, Xu S, Wang X, Gao P, Fan K, He Y, Zhou D, Gong Y, Zhong G, Liu Z. A Bacillus velezensis strain isolated from oats with disease-preventing and growth-promoting properties. Sci Rep 2024; 14:12950. [PMID: 38839805 PMCID: PMC11153497 DOI: 10.1038/s41598-024-63756-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 05/31/2024] [Indexed: 06/07/2024] Open
Abstract
Endophytes have been shown to promote plant growth and health. In the present study, a Bacillus velezensis CH1 (CH1) strain was isolated and identified from high-quality oats, which was capable of producing indole-3-acetic acid (IAA) and strong biofilms, and capabilities in the nitrogen-fixing and iron carriers. CH1 has a 3920 kb chromosome with 47.3% GC content and 3776 code genes. Compared genome analysis showed that the largest proportion of the COG database was metabolism-related (44.79%), and 1135 out of 1508 genes were associated with the function "biosynthesis, transport, and catabolism of secondary metabolites." Furthermore, thirteen gene clusters had been identified in CH1, which were responsible for the synthesis of fifteen secondary metabolites that exhibit antifungal and antibacterial properties. Additionally, the strain harbors genes involved in plant growth promotion, such as seven putative genes for IAA production, spermidine and polyamine synthase genes, along with multiple membrane-associated genes. The enrichment of these functions was strong evidence of the antimicrobial properties of strain CH1, which has the potential to be a biofertilizer for promoting oat growth and disease resistance.
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Affiliation(s)
- Chao Cheng
- School of Life Science and Technology, Jining Normal University, Ulanqab, 012000, China.
| | - Shaofeng Su
- Inner Mongolia Academy of Agriculture and Husbandry Science, Key Laboratory of Black Soil Protection and Utilization, Ministry of Agriculture and Rural Affairs, Hohhot, 010000, China
| | - Suling Bo
- College of Computer Information, Inner Mongolia Medical University, Hohhot, 010000, China
| | - Chengzhong Zheng
- Ulanqab Institute for Agricultural and Forestry Science, Ulanqab, 012000, China
| | - Chunfang Liu
- Ulanqab Center for Disease Control and Prevention, Ulanqab, 012000, China
| | - Linchong Zhang
- Jinyu Baoling Biological Drugs Co., LTD, Hohhot, 010000, China
| | - Songhe Xu
- School of Life Science and Technology, Jining Normal University, Ulanqab, 012000, China
| | - Xiaoyun Wang
- School of Life Science and Technology, Jining Normal University, Ulanqab, 012000, China
| | - Pengfei Gao
- Vocational and Technical College of Ulanqab, Ulanqab, 012000, China
| | - Kongxi Fan
- Inner Mongolia Agricultural University, Hohhot, 010000, China
| | - Yiwei He
- School of Life Science and Technology, Jining Normal University, Ulanqab, 012000, China
| | - Di Zhou
- The Second Affiliated Hospital of Inner Mongolia Medical University, Hohhot, 010000, China
| | - Yanchun Gong
- Agriculture and Animal Husbandry Technology Promotion Center of Inner Mongolia, Hohhot, 010000, China
| | - Gang Zhong
- Agriculture and Animal Husbandry Technology Promotion Center of Inner Mongolia, Hohhot, 010000, China
| | - Zhiguo Liu
- Inner Mongolia Agricultural University, Hohhot, 010000, China.
- Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, 100000, China.
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2
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Lewis IA. Boundary flux analysis: an emerging strategy for investigating metabolic pathway activity in large cohorts. Curr Opin Biotechnol 2024; 85:103027. [PMID: 38061263 DOI: 10.1016/j.copbio.2023.103027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 11/02/2023] [Accepted: 11/15/2023] [Indexed: 02/09/2024]
Abstract
Many biological phenotypes are rooted in metabolic pathway activity rather than the concentrations of individual metabolites. Despite this, most metabolomics studies only capture steady-state metabolism - not metabolic flux. Although sophisticated metabolic flux analysis strategies have been developed, these methods are technically challenging and difficult to implement in large-cohort studies. Recently, a new boundary flux analysis (BFA) approach has emerged that captures large-scale metabolic flux phenotypes by quantifying changes in metabolite levels in the media of cultured cells. This approach is advantageous because it is relatively easy to implement yet captures complex metabolic flux phenotypes. We describe the opportunities and challenges of BFA and illustrate how it can be harnessed to investigate a wide transect of biological phenomena.
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Affiliation(s)
- Ian A Lewis
- Alberta Centre for Advanced Diagnostics, Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada.
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3
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Gheorghita AA, Wozniak DJ, Parsek MR, Howell PL. Pseudomonas aeruginosa biofilm exopolysaccharides: assembly, function, and degradation. FEMS Microbiol Rev 2023; 47:fuad060. [PMID: 37884397 PMCID: PMC10644985 DOI: 10.1093/femsre/fuad060] [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: 04/21/2023] [Revised: 10/04/2023] [Accepted: 10/25/2023] [Indexed: 10/28/2023] Open
Abstract
The biofilm matrix is a fortress; sheltering bacteria in a protective and nourishing barrier that allows for growth and adaptation to various surroundings. A variety of different components are found within the matrix including water, lipids, proteins, extracellular DNA, RNA, membrane vesicles, phages, and exopolysaccharides. As part of its biofilm matrix, Pseudomonas aeruginosa is genetically capable of producing three chemically distinct exopolysaccharides - alginate, Pel, and Psl - each of which has a distinct role in biofilm formation and immune evasion during infection. The polymers are produced by highly conserved mechanisms of secretion, involving many proteins that span both the inner and outer bacterial membranes. Experimentally determined structures, predictive modelling of proteins whose structures are yet to be solved, and structural homology comparisons give us insight into the molecular mechanisms of these secretion systems, from polymer synthesis to modification and export. Here, we review recent advances that enhance our understanding of P. aeruginosa multiprotein exopolysaccharide biosynthetic complexes, and how the glycoside hydrolases/lyases within these systems have been commandeered for antimicrobial applications.
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Affiliation(s)
- Andreea A Gheorghita
- Program in Molecular Medicine, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Medical Science Building, 1 King's College Cir, Toronto, ON M5S 1A8, Canada
| | - Daniel J Wozniak
- Department of Microbial Infection and Immunity, The Ohio State University College of Medicine, 776 Biomedical Research Tower, 460 W 12th Ave, Columbus, OH 43210, United States
- Department of Microbiology, The Ohio State University College, Biological Sciences Bldg, 105, 484 W 12th Ave, Columbus, OH 43210, United States
| | - Matthew R Parsek
- Department of Microbiology, University of Washington, Health Sciences Bldg, 1705 NE Pacific St, Seattle, WA 98195-7735, United States
| | - P Lynne Howell
- Program in Molecular Medicine, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, 686 Bay St, Toronto, ON M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Medical Science Building, 1 King's College Cir, Toronto, ON M5S 1A8, Canada
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4
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Dolan JP, Cosgrove SC, Miller GJ. Biocatalytic Approaches to Building Blocks for Enzymatic and Chemical Glycan Synthesis. JACS AU 2023; 3:47-61. [PMID: 36711082 PMCID: PMC9875253 DOI: 10.1021/jacsau.2c00529] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
While the field of biocatalysis has bloomed over the past 20-30 years, advances in the understanding and improvement of carbohydrate-active enzymes, in particular, the sugar nucleotides involved in glycan building block biosynthesis, have progressed relatively more slowly. This perspective highlights the need for further insight into substrate promiscuity and the use of biocatalysis fundamentals (rational design, directed evolution, immobilization) to expand substrate scopes toward such carbohydrate building block syntheses and/or to improve enzyme stability, kinetics, or turnover. Further, it explores the growing premise of using biocatalysis to provide simple, cost-effective access to stereochemically defined carbohydrate materials, which can undergo late-stage chemical functionalization or automated glycan synthesis/polymerization.
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5
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Ali M, Nishawy E, Ramadan WA, Ewas M, Rizk MS, Sief-Eldein AGM, El-Zayat MAS, Hassan AHM, Guo M, Hu GW, Wang S, Ahmed FA, Amar MH, Wang QF. Molecular characterization of a Novel NAD+-dependent farnesol dehydrogenase SoFLDH gene involved in sesquiterpenoid synthases from Salvia officinalis. PLoS One 2022; 17:e0269045. [PMID: 35657794 PMCID: PMC9165828 DOI: 10.1371/journal.pone.0269045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 05/12/2022] [Indexed: 11/25/2022] Open
Abstract
Salvia officinalis is one of the most important medicinal and aromatic plants in terms of nutritional and medicinal value because it contains a variety of vital active ingredients. Terpenoid compounds, particularly monoterpenes (C10) and sesquiterpenes, are the most important and abundant among these active substances (C15). Terpenes play a variety of roles and have beneficial biological properties in plants. With these considerations, the current study sought to clone theNAD+-dependent farnesol dehydrogenase (SoFLDH, EC: 1.1.1.354) gene from S. officinalis. Functional analysis revealed that, SoFLDH has an open reading frame of 2,580 base pairs that encodes 860 amino acids.SoFLDH has two conserved domains and four types of highly conserved motifs: YxxxK, RXR, RR (X8) W, TGxxGhaG. However, SoFLDH was cloned from Salvia officinalis leaves and functionally overexpressed in Arabidopsis thaliana to investigate its role in sesquiterpenoid synthases. In comparison to the transgenic plants, the wild-type plants showed a slight delay in growth and flowering formation. To this end, a gas chromatography-mass spectrometry analysis revealed that SoFLDH transgenic plants were responsible for numerous forms of terpene synthesis, particularly sesquiterpene. These results provide a base for further investigation on SoFLDH gene role and elucidating the regulatory mechanisms for sesquiterpene synthesis in S. offcinalis. And our study paves the way for the future metabolic engineering of the biosynthesis of useful terpene compounds in S. offcinalis.
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Affiliation(s)
- Mohammed Ali
- Department of Genetic Resources, Desert Research Center, Cairo, Egypt
| | - Elsayed Nishawy
- Department of Genetic Resources, Desert Research Center, Cairo, Egypt
| | - Walaa A. Ramadan
- Genetics and Cytology Department, Biotechnology Research institute, National Research Centre, Giza, Egypt
| | - Mohamed Ewas
- Department of Genetic Resources, Desert Research Center, Cairo, Egypt
| | - Mokhtar Said Rizk
- Department of Genetic Resources, Desert Research Center, Cairo, Egypt
| | | | | | | | - Mingquan Guo
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, China
| | - Guang-Wan Hu
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, China
| | | | - Fatma A. Ahmed
- Department of Medicinal and Aromatic Plants, Desert Research Center, Cairo, Egypt
| | - Mohamed Hamdy Amar
- Department of Genetic Resources, Desert Research Center, Cairo, Egypt
- * E-mail:
| | - Qing-Feng Wang
- Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, China
- Hubei Minzu University, Enshi, China
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6
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Le Mauff F, Razvi E, Reichhardt C, Sivarajah P, Parsek MR, Howell PL, Sheppard DC. The Pel polysaccharide is predominantly composed of a dimeric repeat of α-1,4 linked galactosamine and N-acetylgalactosamine. Commun Biol 2022; 5:502. [PMID: 35618750 PMCID: PMC9135694 DOI: 10.1038/s42003-022-03453-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 05/06/2022] [Indexed: 12/20/2022] Open
Abstract
The genetic capacity to synthesize the biofilm matrix exopolysaccharide Pel is widespread among Gram-negative and Gram-positive bacteria. However, its exact chemical structure has been challenging to determine. Using a Pseudomonas aeruginosa strain engineered to overproduce Pel, improvements to the isolation procedure, and selective hydrolysis with the glycoside hydrolase PelAh, we demonstrate that Pel is a partially de-N-acetylated linear polymer of α-1,4-N-acetylgalactosamine comprised predominantly of dimeric repeats of galactosamine and N-acetylgalactosamine. The structure of the Pel exopolysaccharide from Pseudomonas aeruginosa is fully characterized.
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Affiliation(s)
- François Le Mauff
- Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, QC, Canada.,Infectious Disease in Global Health Program, McGill University Health Centre, Montreal, QC, Canada.,McGill Interdisciplinary Initiative in Infection and Immunity, Montreal, QC, Canada
| | - Erum Razvi
- Program in Molecular Medicine, Research Institute The Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Courtney Reichhardt
- Department of Microbiology, University of Washington, Seattle, WA, USA.,Department of Chemistry, Washington University, St. Louis, MO, 63130, USA
| | - Piyanka Sivarajah
- Program in Molecular Medicine, Research Institute The Hospital for Sick Children, Toronto, ON, Canada
| | - Matthew R Parsek
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - P Lynne Howell
- Program in Molecular Medicine, Research Institute The Hospital for Sick Children, Toronto, ON, Canada. .,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
| | - Donald C Sheppard
- Department of Microbiology and Immunology, Faculty of Medicine, McGill University, Montreal, QC, Canada. .,Infectious Disease in Global Health Program, McGill University Health Centre, Montreal, QC, Canada. .,McGill Interdisciplinary Initiative in Infection and Immunity, Montreal, QC, Canada.
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Comparative Genome Analysis Reveals Phylogenetic Identity of Bacillus velezensis HNA3 and Genomic Insights into Its Plant Growth Promotion and Biocontrol Effects. Microbiol Spectr 2022; 10:e0216921. [PMID: 35107331 PMCID: PMC8809340 DOI: 10.1128/spectrum.02169-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Bacillus velezensis HNA3, a potential plant growth promoter and biocontrol rhizobacterium, was isolated from plant rhizosphere soils in our previous work. Here, we sequenced the entire genome of the HNA3 strain and performed a comparative genome analysis. We found that HNA3 has a 3,929-kb chromosome with 46.5% GC content and 4,080 CDSs. We reclassified HNA3 as a Bacillus velezensis strain by core genome analysis between HNA3 and 74 previously defined Bacillus strains in the evolutionary tree. A comparative genomic analysis among Bacillus velezensis HNA3, Bacillus velezensis FZB42, Bacillus amyloliquefaciens DSM7, and Bacillus subtilis 168 showed that only HNA3 has one predicated secretory protein feruloyl esterase that catalyzes the hydrolysis of plant cell wall polysaccharides. The analysis of gene clusters revealed that whole biosynthetic gene clusters type Lanthipeptide was exclusively identified in HNA3 and might lead to the synthesis of new bioactive compounds. Twelve gene clusters were detected in HNA3 responsible for the synthesis of 14 secondary metabolites including Bacillaene, Fengycin, Bacillomycin D, Surfactin, Plipastatin, Mycosubtilin, Paenilarvins, Macrolactin, Difficidin, Amylocyclicin, Bacilysin, Iturin, Bacillibactin, Paenibactin, and others. HNA3 has 77 genes encoding for possible antifungal and antibacterial secreting carbohydrate active enzymes. It also contains genes involved in plant growth promotion, such as 11 putative indole acetic acid (IAA)-producing genes, spermidine and polyamine synthase genes, volatile compound producing genes, and multiple biofilm related genes. HNA3 also has 19 phosphatase genes involved in phosphorus solubilization. Our results provide insights into the genetic characteristics responsible for the bioactivities and potential application of HNA3 as plant growth-promoting strain in ecological agriculture. IMPORTANCE This study is the primary initiative to identify Bacillus velezensis HNA3 whole genome sequence and reveal its genomic properties as an effective biocontrol agent against plant pathogens and a plant growth stimulator. HNA3 genetic profile can be used as a reference for future studies that can be applied as a highly effective biofertilizer and biofungicide inoculum to improve agriculture productivity. HNA3 reclassified in the phylogenetic tree which may be helpful for highly effective strain engineering and taxonomy. The genetic comparison among HNA3 and closely similar species B. velezensis FZB42, B. amyloliquefaciens DSM7, and B. subtilis 168 demonstrates some distinctive genetic properties of HNA3 and provides a basis for the genetic diversity of the Bacillus genus, which allows developing more effective eco-friendly resources for agriculture and separation of Bacillus velezensis as distinct species in the phylogenetic tree.
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Zhang J, Yang J, Li Q, Ding J, Liu L, Sun T, Li H. Preparation of WPU-based super-amphiphobic coatings functionalized by in situ modified SiO x particles and their anti-biofilm mechanism. Biomater Sci 2021; 9:7504-7521. [PMID: 34643189 DOI: 10.1039/d1bm01285a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Fabrication of anti-wetting coatings with anti-biofouling and anti-biofilm properties has become a hot spot of attention in recent years. However, the anti-biofilm mechanism of anti-bacterial adhesion coatings with different wet resistance properties has not been explored in detail. In this work, SiOx micro-nano particles were prepared by the Stöber method and were in situ modified. The SiOx/waterborne polyurethane (WPU) coatings were prepared by the drop coating method, and the coatings with different hydrophobic and oleophobic properties were constructed by modifying the process conditions using SiOx micro-nano particles as the roughness construction factor. Taking the dominant spoilage bacteria of aquatic products, Shewanella putrefaciens as the object, the anti-bacterial adhesion properties and anti-biofilm mechanism of the SiOx/WPU coatings were investigated. The results show that, with the unmodified SiOx particles increasing from 1.2% (w/V) to 4.0% (w/V), the hydrophobicity and thermal stability of the SiOx/WPU coatings are significantly enhanced, but the oil repellency becomes worse due to the mesoporous structure. After SiOx micro-nano particles are modified with 1H,1H,2H,2H-perfluorooctyl trichlorosilane (PFOTS), the surface energy of the SiOx/WPU coatings is decreased, the liquid repellency is improved, and the surfaces are rough with the appearance of fluorocarbon compounds, but the thermal stabilities are slightly reduced. Among them, after the secondary modification of SiOx micro-nano particles, the SiOx/WPU coatings showed excellent oil repellency, lower surface energies and higher fluorocarbon content on the surface. Particularly, SiOx/WPU coatings exhibited super-amphiphobicity after adjusting the amount of concentrated ammonia added during the secondary modification process. Meanwhile, we found that for the hydrophobic SiOx/WPU coatings, the stronger the oleophobic property, the greater the anti-bacterial adhesion ability is, while the anti-bacterial adhesion ability of hydrophobic and selectively oleophobic or superhydrophobic and oleophobic SiOx/WPU coatings is poor than that of amphiphilic SiOx/WPU coatings. However, because the super-amphiphobic SiOx/WPU coatings can be in the Cassie state with the bacterial solution for a long time, it can "capture" enough air to inhibit the irreversible adhesion of the bacteria. More importantly, the coatings can also inhibit the metabolic activity, secretion of extracellular polysaccharides, and activities of ATPase and AKP of the adherent bacteria, so it has a better anti-biofilm property. The anti-biofilm coatings can be used as food packaging materials or coated on the inner surface of packaging boxes to prevent the microbial infection.
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Affiliation(s)
- Jiatao Zhang
- National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, College of Food Science and Engineering, Bohai University, Jinzhou 121013, China.
| | - Junyi Yang
- National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, College of Food Science and Engineering, Bohai University, Jinzhou 121013, China.
| | - Qiuying Li
- National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, College of Food Science and Engineering, Bohai University, Jinzhou 121013, China.
| | - Jie Ding
- National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, College of Food Science and Engineering, Bohai University, Jinzhou 121013, China.
| | - Liangjun Liu
- National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, College of Food Science and Engineering, Bohai University, Jinzhou 121013, China.
| | - Tong Sun
- National & Local Joint Engineering Research Center of Storage, Processing and Safety Control Technology for Fresh Agricultural and Aquatic Products, College of Food Science and Engineering, Bohai University, Jinzhou 121013, China.
| | - Hehe Li
- Beijing Laboratory of Food Quality and Safety, Beijing Technology and Business University, Beijing 100048, China.
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9
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Koller F, Lassak J. Two RmlC homologs catalyze dTDP-4-keto-6-deoxy-D-glucose epimerization in Pseudomonas putida KT2440. Sci Rep 2021; 11:11991. [PMID: 34099824 PMCID: PMC8184846 DOI: 10.1038/s41598-021-91421-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/26/2021] [Indexed: 11/09/2022] Open
Abstract
l-Rhamnose is an important monosaccharide both as nutrient source and as building block in prokaryotic glycoproteins and glycolipids. Generation of those composite molecules requires activated precursors being provided e. g. in form of nucleotide sugars such as dTDP-β-l-rhamnose (dTDP-l-Rha). dTDP-l-Rha is synthesized in a conserved 4-step reaction which is canonically catalyzed by the enzymes RmlABCD. An intact pathway is especially important for the fitness of pseudomonads, as dTDP-l-Rha is essential for the activation of the polyproline specific translation elongation factor EF-P in these bacteria. Within the scope of this study, we investigated the dTDP-l-Rha-biosynthesis route of Pseudomonas putida KT2440 with a focus on the last two steps. Bioinformatic analysis in combination with a screening approach revealed that epimerization of dTDP-4-keto-6-deoxy-d-glucose to dTDP-4-keto-6-deoxy-l-mannose is catalyzed by the two paralogous proteins PP_1782 (RmlC1) and PP_0265 (RmlC2), whereas the reduction to the final product is solely mediated by PP_1784 (RmlD). Thus, we also exclude the distinct RmlD homolog PP_0500 and the genetically linked nucleoside diphosphate-sugar epimerase PP_0501 to be involved in dTDP-l-Rha formation, other than suggested by certain databases. Together our analysis contributes to the molecular understanding how this important nucleotide-sugar is synthesized in pseudomonads.
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Affiliation(s)
- Franziska Koller
- Department Biology I, Microbiology, Ludwig-Maximilians-Universität München, Planegg/Martinsried, Germany
| | - Jürgen Lassak
- Department Biology I, Microbiology, Ludwig-Maximilians-Universität München, Planegg/Martinsried, Germany.
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10
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Whitfield GB, Howell PL. The Matrix Revisited: Opening Night for the Pel Polysaccharide Across Eubacterial Kingdoms. Microbiol Insights 2021; 14:1178636120988588. [PMID: 33642867 PMCID: PMC7890745 DOI: 10.1177/1178636120988588] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 12/16/2020] [Indexed: 01/29/2023] Open
Abstract
Bacteria synthesize and export adhesive macromolecules to enable biofilm formation. These macromolecules, collectively called the biofilm matrix, are structurally varied and often unique to specific bacterial species or subspecies. This heterogeneity in matrix utilization makes it difficult to facilitate direct comparison between biofilm formation mechanisms of different bacterial species. Despite this, some matrix components, in particular the polysaccharides poly-β-1,6-N-acetyl-glucosamine (PNAG) and bacterial cellulose, are utilized by many Gram-negative species for biofilm formation. However, there is a very narrow distribution of these components across Gram-positive organisms, whose biofilm matrix determinants remain largely undiscovered. We found that a genetic locus required for the production of a biofilm matrix component of P. aeruginosa, the Pel polysaccharide, is widespread in Gram-negative bacteria and that there is a variant form of this cluster present in many Gram-positive bacterial species. We demonstrated that this locus is required for biofilm formation by Bacillus cereus ATCC 10987, produces a polysaccharide that is similar to Pel, and is post-translationally regulated by cyclic-3′,5′-dimeric-guanosine monophosphate (c-di-GMP) in a manner identical to P. aeruginosa. However, while the proposed mechanism for Pel production appears remarkably similar between B. cereus and P. aeruginosa, we identified several key differences between Gram-negative and Gram-positive Pel biosynthetic components in other monoderms. In particular, 4 different architectural subtypes of the c-di-GMP-binding component PelD were identified, including 1 found only in Streptococci that has entirely lost the c-di-GMP recognition domain. These observations highlight how existing multi-component bacterial machines can be subtly tweaked to adapt to the unique physiology and regulatory mechanisms of Gram-positive organisms. Collectively, our analyses suggest that the Pel biosynthetic locus is one of the most phylogenetically widespread biofilm matrix determinants in bacteria, and that its mechanism of production and regulation is extraordinarily conserved across the majority of organisms that possess it.
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Affiliation(s)
- Gregory B Whitfield
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, ON, Canada.,Département de Microbiologie, Infectiologie, et Immunologie, Université de Montréal, QC, Canada
| | - P Lynne Howell
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, ON, Canada
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11
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Fushinobu S. Molecular evolution and functional divergence of UDP-hexose 4-epimerases. Curr Opin Chem Biol 2020; 61:53-62. [PMID: 33171387 DOI: 10.1016/j.cbpa.2020.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/23/2020] [Accepted: 09/25/2020] [Indexed: 01/08/2023]
Abstract
UDP-glucose 4-epimerase (GalE) catalyzes the interconversion of UDP-glucose (UDP-Glc) and UDP-galactose (UDP-Gal) and/or the interconversion of UDP-N-acetylglucosamine (UDP-GlcNAc) and UDP-N-acetylgalactosamine (UDP-GalNAc) in sugar metabolism. GalEs belong to the short-chain dehydrogenase/reductase superfamily, use a conserved 'transient keto intermediate' mechanism and have variable substrate specificity. GalEs have been classified into three groups based on substrate specificity: group 1 prefers UDP-Glc/Gal, group 3 prefers UDP-GlcNAc/GalNAc, and group 2 has comparable activities for both types of the substrates. The phylogenetic relationship and structural basis for the specificities of GalEs revealed possible molecular evolution of UDP-hexose 4-epimerases in various organisms. Based on the recent advances in studies on GalEs and related enzymes, an updated view of their evolutional diversification is presented.
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Affiliation(s)
- Shinya Fushinobu
- Department of Biotechnology, The University of Tokyo, Tokyo, 113-8657, Japan; Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, 113-8657, Japan.
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