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Dvorak KR, Tepe JJ. Advances in the total synthesis of bis- and tris-indole alkaloids containing N-heterocyclic linker moieties. Nat Prod Rep 2024; 41:1264-1293. [PMID: 38666377 PMCID: PMC11323739 DOI: 10.1039/d4np00012a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Indexed: 08/15/2024]
Abstract
The past several years have seen an increase in the discovery and isolation of natural products of the indole alkaloid class. Bis- and tris-indole alkaloids are classes of natural products that have been shown to display diverse, potent biological activities. Of particular interest are bis- and tris-indole alkaloids containing N-heterocyclic linker moieties. It has been reported that more than 85% of biologically active compounds contain one or more heterocyclic moieties; of these, N-heterocycles have been identified as the most prevalent. The goal of this review is to provide a detailed overview of the recent advances in isolation and total synthesis of bis- and tris-indole alkaloids that contain N-heterocyclic linker moieties. The known biological activities of these natural products will also be discussed.
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2
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Li Y, Ding W, Yin J, Li X, Tian X, Xiao Z, Wang F, Yin H. 2,3-Dimethoxycinnamic Acid from a Marine Actinomycete, a Promising Quorum Sensing Inhibitor in Chromobacterium violaceum. Mar Drugs 2024; 22:177. [PMID: 38667794 PMCID: PMC11051081 DOI: 10.3390/md22040177] [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] [Revised: 04/09/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
An ethyl acetate extract of a marine actinomycete strain, Nocardiopsis mentallicus SCSIO 53858, isolated from a deep-sea sediment sample in the South China Sea, exhibited anti-quorum-sensing (QS) activity against Chromobacterium violaceum CV026. Guided by the anti-QS activity, a novel active compound was isolated and purified from the extract and was identified as 2,3-dimethoxycinnamic acid (2,3-DCA) through spectral data analysis. At a concentration of 150 μg/mL, 2,3-DCA exhibited robust inhibitory effects on three QS-regulated traits of C. violaceum CV026: violacein production, swarming motility, and biofilm formation, with inhibition rates of 73.9%, 65.9%, and 37.8%, respectively. The quantitative reverse transcription polymerase chain reaction results indicated that 2,3-DCA can disrupt the QS system in C. violaceum CV026 by effectively suppressing the expression of QS-related genes, including cviR, vioA, vioB, and vioE. Molecular docking analysis revealed that 2,3-DCA hinders the QS system by competitively binding to the same binding pocket on the CviR receptor as the natural signal molecule N-hexanoyl-L-homoserine lactone. Collectively, these findings suggest that 2,3-DCA exhibits promising potential as an inhibitor of QS systems, providing a potential solution to the emerging problem of bacterial resistance.
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Affiliation(s)
- Yanqun Li
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; (Y.L.); (W.D.); (J.Y.); (X.L.); (X.T.); (Z.X.); (F.W.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenping Ding
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; (Y.L.); (W.D.); (J.Y.); (X.L.); (X.T.); (Z.X.); (F.W.)
| | - Jiajia Yin
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; (Y.L.); (W.D.); (J.Y.); (X.L.); (X.T.); (Z.X.); (F.W.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xingyu Li
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; (Y.L.); (W.D.); (J.Y.); (X.L.); (X.T.); (Z.X.); (F.W.)
| | - Xinpeng Tian
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; (Y.L.); (W.D.); (J.Y.); (X.L.); (X.T.); (Z.X.); (F.W.)
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
- Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572025, China
| | - Zhihui Xiao
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; (Y.L.); (W.D.); (J.Y.); (X.L.); (X.T.); (Z.X.); (F.W.)
| | - Fazuo Wang
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; (Y.L.); (W.D.); (J.Y.); (X.L.); (X.T.); (Z.X.); (F.W.)
| | - Hao Yin
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; (Y.L.); (W.D.); (J.Y.); (X.L.); (X.T.); (Z.X.); (F.W.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
- Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572025, China
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3
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Hooe S, Thakur M, Lasarte-Aragonés G, Breger JC, Walper SA, Medintz IL, Ellis GA. Exploration of the In Vitro Violacein Synthetic Pathway with Substrate Analogues. ACS OMEGA 2024; 9:3894-3904. [PMID: 38284012 PMCID: PMC10809250 DOI: 10.1021/acsomega.3c08233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/21/2023] [Accepted: 12/26/2023] [Indexed: 01/30/2024]
Abstract
Evolution has gifted enzymes with the ability to synthesize an abundance of small molecules with incredible control over efficiency and selectivity. Central to an enzyme's role is the ability to selectively catalyze reactions in the milieu of chemicals within a cell. However, for chemists it is often desirable to extend the substrate scope of reactions to produce analogue(s) of a desired product and therefore some degree of enzyme promiscuity is often desired. Herein, we examine this dichotomy in the context of the violacein biosynthetic pathway. Importantly, we chose to interrogate this pathway with tryptophan analogues in vitro, to mitigate possible interference from cellular components and endogenous tryptophan. A total of nine tryptophan analogues were screened for by analyzing the substrate promiscuity of the initial enzyme, VioA, and compared to the substrate tryptophan. These results suggested that for VioA, substitutions at either the 2- or 4-position of tryptophan were not viable. The seven analogues that showed successful substrate conversion by VioA were then applied to the five enzyme cascade (VioABEDC) for the production of violacein, where l-tryptophan and 6-fluoro-l-tryptophan were the only substrates which were successfully converted to the corresponding violacein derivative(s). However, many of the other tryptophan analogues did convert to various substituted intermediaries. Overall, our results show substrate promiscuity with the initial enzyme, VioA, but much less for the full pathway. This work demonstrates the complexity involved when attempting to analyze substrate analogues within multienzymatic cascades, where each enzyme involved within the cascade possesses its own inherent promiscuity, which must be compatible with the remaining enzymes in the cascade for successful formation of a desired product.
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Affiliation(s)
- Shelby
L. Hooe
- National
Research Council, Washington, D.C. 20001, United States
- Center
for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Meghna Thakur
- Center
for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- College
of Science, George Mason University, Fairfax, Virginia 22030, United States
| | - Guillermo Lasarte-Aragonés
- Center
for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- College
of Science, George Mason University, Fairfax, Virginia 22030, United States
| | - Joyce C. Breger
- Center
for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Scott A. Walper
- Center
for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Igor L. Medintz
- Center
for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Gregory A. Ellis
- Center
for Bio/Molecular Science and Engineering Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
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Senthil R, Archunan G, Vithya D, Saravanan KM. Hexadecanoic acid analogs as potential CviR-mediated quorum sensing inhibitors in Chromobacterium violaceum: an in silico study. J Biomol Struct Dyn 2024:1-10. [PMID: 38165661 DOI: 10.1080/07391102.2023.2299945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 12/20/2023] [Indexed: 01/04/2024]
Abstract
Chromobacterium violaceum is a Gram-negative, rod-shaped and opportunistic human pathogen. C. violaceum is resistant to various antibiotics due to the production of quorum sensing (QS)-controlled virulence factor and biofilm formation. Hence, we need to find alternative strategies to overcome the antimicrobial resistance and biofilm formation in Gram-negative bacteria. QS is a mechanism in which bacteria's ability to regulate the virulence factors and biofilm formations leads to disease progression. Previously, hexadecanoic acid was identified as a CviR-mediated quorum-sensing inhibitor. In this study, we aimed to discover potential analogs of hexadecanoic acid as a CviR-mediated quorum-sensing inhibitor against C. violaceum by using ADME/T prediction, density functional theory, molecular docking, molecular dynamics and free energy binding calculations. ADME/T properties predicted for analogs were acceptable for human oral absorption and feasibility. The highest occupied molecular orbitals and lowest unoccupied molecular orbitals gap energies predicted and found oleic acid with -0.3748 energies. Docosatrienoic acid exhibited the highest binding affinity -8.15 Kcal/mol and strong and stable interactions with the amino acid residues on the active site of the CviR protein. These compounds on MD simulations for 100 ns show strong hydrogen-bonding interactions with the protein and remain stable inside the active site. Our results suggest hexadecanoic acid analogs could serve as anti-QS and anti-biofilm molecules for treating C. violaceum infections. However, further validation and investigation of these inhibitors against CviR are needed to claim their candidacy for clinical trials.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Renganathan Senthil
- Department of Bioinformatics, School of Lifesciences, Vel's Institute of Science, Technology and Advanced Studies, Pallavaram, Chennai, Tamil Nadu, India
- Lysine Biotech Private Limited, Taramani, Chennai, Tamil Nadu, India
| | - Govindaraju Archunan
- Dean-Research, Maruthupandiyar College (Affiliated to Bharathidasan University), Thanjavur, Tamil Nadu, India
| | - Dharmaraj Vithya
- Department of Biotechnology, Dhanalakshmi Srinivasan College of Arts and Science for Women (Affiliated to Bharathidasan University), Perambalur, Tamil Nadu, India
| | - Konda Mani Saravanan
- Department of Biotechnology, Bharath Institute of Higher Education and Research, Chennai, Tamil Nadu, India
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Shi X, Zhao G, Li H, Zhao Z, Li W, Wu M, Du YL. Hydroxytryptophan biosynthesis by a family of heme-dependent enzymes in bacteria. Nat Chem Biol 2023; 19:1415-1422. [PMID: 37653171 DOI: 10.1038/s41589-023-01416-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 08/03/2023] [Indexed: 09/02/2023]
Abstract
Hydroxytryptophan serves as a chemical precursor to a variety of bioactive specialized metabolites, including the human neurotransmitter serotonin and the hormone melatonin. Although the human and animal routes to hydroxytryptophan have been known for decades, how bacteria catalyze tryptophan indole hydroxylation remains a mystery. Here we report a class of tryptophan hydroxylases that are involved in various bacterial metabolic pathways. These enzymes utilize a histidine-ligated heme cofactor and molecular oxygen or hydrogen peroxide to catalyze regioselective hydroxylation on the tryptophan indole moiety, which is mechanistically distinct from their animal counterparts from the nonheme iron enzyme family. Through genome mining, we also identify members that can hydroxylate the tryptophan indole ring at alternative positions. Our results not only reveal a conserved way to synthesize hydroxytryptophans in bacteria but also provide a valuable enzyme toolbox for biocatalysis. As proof of concept, we assemble a highly efficient pathway for melatonin in a bacterial host.
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Affiliation(s)
- Xinjie Shi
- The Fourth Affiliated Hospital and Department of Microbiology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Guiyun Zhao
- The Fourth Affiliated Hospital and Department of Microbiology, School of Medicine, Zhejiang University, Hangzhou, China
- Department of Pharmacy, The Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, China
| | - Hu Li
- Polytechnic Institute, Zhejiang University, Hangzhou, China
| | - Zhijie Zhao
- The Fourth Affiliated Hospital and Department of Microbiology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Wei Li
- The Fourth Affiliated Hospital and Department of Microbiology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Miaolian Wu
- Department of Pharmacy, The Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, China
| | - Yi-Ling Du
- The Fourth Affiliated Hospital and Department of Microbiology, School of Medicine, Zhejiang University, Hangzhou, China.
- Department of Pharmacy, The Fourth Affiliated Hospital, School of Medicine, Zhejiang University, Yiwu, China.
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, China.
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Hangzhou, China.
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Ahearne A, Phillips KE, Knehans T, Hoing M, Dowd SE, Stevens DC. Chromosomal organization of biosynthetic gene clusters, including those of nine novel species, suggests plasticity of myxobacterial specialized metabolism. Front Microbiol 2023; 14:1227206. [PMID: 37601375 PMCID: PMC10435759 DOI: 10.3389/fmicb.2023.1227206] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/11/2023] [Indexed: 08/22/2023] Open
Abstract
Introduction Natural products discovered from bacteria provide critically needed therapeutic leads for drug discovery, and myxobacteria are an established source for metabolites with unique chemical scaffolds and biological activities. Myxobacterial genomes accommodate an exceptional number and variety of biosynthetic gene clusters (BGCs) which encode for features involved in specialized metabolism. Methods In this study, we describe the collection, sequencing, and genome mining of 20 myxobacteria isolated from rhizospheric soil samples collected in North America. Results Nine isolates were determined to be novel species of myxobacteria including representatives from the genera Archangium, Myxococcus, Nannocystis, Polyangium, Pyxidicoccus, Sorangium, and Stigmatella. Growth profiles, biochemical assays, and descriptions were provided for all proposed novel species. We assess the BGC content of all isolates and observe differences between Myxococcia and Polyangiia clusters. Discussion Continued discovery and sequencing of novel myxobacteria from the environment provide BGCs for the genome mining pipeline. Utilizing complete or near-complete genome sequences, we compare the chromosomal organization of BGCs of related myxobacteria from various genera and suggest that the spatial proximity of hybrid, modular clusters contributes to the metabolic adaptability of myxobacteria.
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Affiliation(s)
- Andrew Ahearne
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS, United States
| | - Kayleigh E. Phillips
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS, United States
| | - Thomas Knehans
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS, United States
| | - Miranda Hoing
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS, United States
| | - Scot E. Dowd
- Molecular Research LP (MR DNA), Shallowater, TX, United States
| | - David Cole Stevens
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS, United States
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Favero F, Tolentino TA, Fernandes V, Treptow W, Pereira AL, Lira Machado AH. α-Alkylidene δ-lactones inhibit quorum sensing phenotypes in Chromobacterium strain CV026 showing interaction with the CviR receptor. RSC Adv 2023; 13:18045-18057. [PMID: 37323447 PMCID: PMC10267776 DOI: 10.1039/d3ra01975f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023] Open
Abstract
Disruption of bacterial quorum sensing (QS) is presented as a promising strategy to overcome clinically relevant and phytopathogenic bacteria. This work presents α-alkylidene δ-lactones as new chemical scaffolds that inhibit the biosynthesis of violacein in the biosensor strain Chromobacterium CV026. Three molecules displayed higher than 50% violacein reduction when tested at concentrations lower than 625 µM. The most active α-alkylidene δ-lactone inhibited the hydrolysis of chitin concomitantly with the inhibition of violacein production in CV026, suggesting the disruption of its QS machinery. Further, RT-qPCR and competition experiments showed this molecule to be a transcriptional inhibitor of the QS-regulated operon vioABCDE. Docking calculations suggested a good correlation between binding affinity energies and inhibition effects, with all molecules positioned within the CviR autoinducer-binding domain (AIBD). The most active lactone yielded the best binding affinity energy, most probably due to its unprecedented binding with the AIBD. Our results show α-alkylidene δ-lactones as promising chemical scaffolds for the development of new QS inhibitors affecting LuxR/LuxI-systems.
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Affiliation(s)
- Fernanda Favero
- Instituto de Química, Universidade de Brasília, Campus Universitário Darcy Ribeiro Asa Norte Brasília DF 70910-900 Brazil
- Campus of Ceilândia, University of Brasília, Centro Metropolitano Conjunto A, Ceilândia Sul Brasília DF 72220-275 Brazil
| | - Terezinha Alves Tolentino
- Instituto de Química, Universidade de Brasília, Campus Universitário Darcy Ribeiro Asa Norte Brasília DF 70910-900 Brazil
| | - Vinicius Fernandes
- Laboratório de Biologia Teórica e Computacional, Departamento de Biologia Celular, Universidade de Brasília, Campus Universitário Darcy Ribeiro Asa Norte Brasília DF 70910-900 Brazil
| | - Werner Treptow
- Laboratório de Biologia Teórica e Computacional, Departamento de Biologia Celular, Universidade de Brasília, Campus Universitário Darcy Ribeiro Asa Norte Brasília DF 70910-900 Brazil
| | - Alex Leite Pereira
- Campus of Ceilândia, University of Brasília, Centro Metropolitano Conjunto A, Ceilândia Sul Brasília DF 72220-275 Brazil
| | - Angelo Henrique Lira Machado
- Instituto de Química, Universidade de Brasília, Campus Universitário Darcy Ribeiro Asa Norte Brasília DF 70910-900 Brazil
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Di Salvo E, Lo Vecchio G, De Pasquale R, De Maria L, Tardugno R, Vadalà R, Cicero N. Natural Pigments Production and Their Application in Food, Health and Other Industries. Nutrients 2023; 15:nu15081923. [PMID: 37111142 PMCID: PMC10144550 DOI: 10.3390/nu15081923] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/10/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
In addition to fulfilling their function of giving color, many natural pigments are known as interesting bioactive compounds with potential health benefits. These compounds have various applications. In recent times, in the food industry, there has been a spread of natural pigment application in many fields, such as pharmacology and toxicology, in the textile and printing industry and in the dairy and fish industry, with almost all major natural pigment classes being used in at least one sector of the food industry. In this scenario, the cost-effective benefits for the industry will be welcome, but they will be obscured by the benefits for people. Obtaining easily usable, non-toxic, eco-sustainable, cheap and biodegradable pigments represents the future in which researchers should invest.
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Affiliation(s)
- Eleonora Di Salvo
- Departement of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, 98168 Messina, Italy
| | - Giovanna Lo Vecchio
- Departement of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, 98168 Messina, Italy
| | - Rita De Pasquale
- Departement of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, 98168 Messina, Italy
| | - Laura De Maria
- Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Roberta Tardugno
- Department of Pharmacy-Drug Sciences, University of Bari, 70121 Bari, Italy
| | - Rossella Vadalà
- Departement of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, 98168 Messina, Italy
| | - Nicola Cicero
- Departement of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, 98168 Messina, Italy
- Science4life srl, University of Messina, 98168 Messina, Italy
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Ahearne A, Phillips K, Knehans T, Hoing M, Dowd SE, Stevens DC. Chromosomal organization of biosynthetic gene clusters suggests plasticity of myxobacterial specialized metabolism including descriptions for nine novel species: Archangium lansinium sp. nov., Myxococcus landrumus sp. nov., Nannocystis bainbridgea sp. nov., Nannocystis poenicansa sp. nov., Nannocystis radixulma sp. nov., Polyangium mundeleinium sp. nov., Pyxidicoccus parkwaysis sp. nov., Sorangium aterium sp. nov., Stigmatella ashevillena sp. nov. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.08.531766. [PMID: 36945379 PMCID: PMC10028903 DOI: 10.1101/2023.03.08.531766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Natural products discovered from bacteria provide critically needed therapeutic leads for drug discovery, and myxobacteria are an established source for metabolites with unique chemical scaffolds and biological activities. Myxobacterial genomes accommodate an exceptional number and variety of biosynthetic gene clusters (BGCs) which encode for features involved in specialized metabolism. Continued discovery and sequencing of novel myxobacteria from the environment provides BGCs for the genome mining pipeline. Herein, we describe the collection, sequencing, and genome mining of 20 myxobacteria isolated from rhizospheric soil samples collected in North America. Nine isolates where determined to be novel species of myxobacteria including representatives from the genera Archangium, Myxococcus, Nannocystis, Polyangium, Pyxidicoccus, Sorangium, and Stigmatella. Growth profiles, biochemical assays, and descriptions are provided for all proposed novel species. We assess the BGC content of all isolates and observe differences between Myxococcia and Polyangiia clusters. Utilizing complete or near complete genome sequences we compare the chromosomal organization of BGCs of related myxobacteria from various genera and suggest spatial proximity of hybrid, modular clusters contributes to the metabolic adaptability of myxobacteria.
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Affiliation(s)
- Andrew Ahearne
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA
| | - Kayleigh Phillips
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA
| | - Thomas Knehans
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA
| | - Miranda Hoing
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA
| | - Scot E. Dowd
- MR DNA, Molecular Research LP, Shallowater, TX 79363, USA
| | - D. Cole Stevens
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA
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Fermentation in Minimal Media and Fungal Elicitation Enhance Violacein and Deoxyviolacein Production in Two Janthinobacterium Strains. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8120714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Violacein and its biosynthesis by-product deoxyviolacein are valuable natural pigments with different biological activities. Various efforts have been made to enhance violacein and deoxyviolacein production in microbes. However, the effect of different culture media, agitation, and fungal elicitation on biosynthesis in Janthinobacterium has not been evaluated. In this study, the effect of eight different culture media, agitation, and fungal elicitation by Agaricus bisporus on violacein and deoxviolacein production in Janthinobacterium agaricidamnosum DSM 9628 and Janthinobacterium lividum DSM 1552 were examined. The results showed that violacein and deoxviolacein are produced at high-levels when Janthinobacterium is cultivated in minimal media such as Davis minimal broth with glycerol (DMBgly), shipworm basal medium (SBM), and MM9 media. A 50-fold increase was observed in violacein production when Janthinobacterium was cultivated in these media compared to cultivation in Luria–Bertani (LB), nutrient broth (NB), and King’s B (KB). Agitation reduces violacein and deoxyviolacein production, while fungal elicitation decreases violacein but increases deoxyviolacein when Janthinobacterium is cultured in KB media, SBM, and modified SBM (MSBM). An antibacterial assay using various pathogenic bacteria showed that violacein and deoxyviolacein extracted from Janthinobacterium are effective against both Gram-positive and Gram-negative pathogens, confirming their functionality as antibacterial agents. The findings suggest that cultivation in minimal media and fungal elicitation might invoke a stress response, enhancing the production of violacein and deoxviolacein in Janthinobacterium.
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11
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Evidente A. Microbial and Plant Derived Low Risk Pesticides Having Nematocidal Activity. Toxins (Basel) 2022; 14:toxins14120849. [PMID: 36548747 PMCID: PMC9787815 DOI: 10.3390/toxins14120849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 11/25/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Microorganisms, virus, weeds, parasitic plants, insects, and nematodes are among the enemies that induce severe economic losses to agrarian production. Farmers have been forced to combat these enemies using different methods, including mechanical and agronomic strategies, since the beginning of agriculture. The development of agriculture, due to an increased request for food production, which is a consequence to the rapid and noteworthy growth of the world's population, requires the use of more efficient methods to strongly elevate the yield production. Thus, in the last five-to-six decades, a massive and extensive use of chemicals has occurred in agriculture, resulting in heavy negative consequences, such as the increase in environmental pollution and risks for human and animal health. These problems increased with the repetition of treatments, which is due to resistance that natural enemies developed against this massive use of pesticides. There are new control strategies under investigation to develop products, namely biopesticides, with high efficacy and selectivity but based on natural products which are not toxic, and which are biodegradable in a short time. This review is focused on the microbial and plant metabolites with nematocidal activity with potential applications in suitable formulations in greenhouses and fields.
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Affiliation(s)
- Antonio Evidente
- Department of Chemical Science, University of Naples Federico II, Complesso Universitario Monte S. Angelo, Via Cinthia 4, 80126 Naples, Italy;
- Institute of Sciences of Food Production, National Research Council, Via Amendola 122/O, 70125 Bari, Italy
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Lyakhovchenko NS, Travkin VM, Senchenkov VY, Solyanikova IP. Bacterial Violacein: Properties, Biosynthesis and Application Prospects. APPL BIOCHEM MICRO+ 2022. [DOI: 10.1134/s0003683822060072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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13
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Guo H, Ryan JC, Song X, Mallet A, Zhang M, Pabst V, Decrulle AL, Ejsmont P, Wintermute EH, Lindner AB. Spatial engineering of E. coli with addressable phase-separated RNAs. Cell 2022; 185:3823-3837.e23. [PMID: 36179672 DOI: 10.1016/j.cell.2022.09.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 04/25/2022] [Accepted: 09/06/2022] [Indexed: 01/26/2023]
Abstract
Biochemical processes often require spatial regulation and specific microenvironments. The general lack of organelles in bacteria limits the potential of bioengineering complex intracellular reactions. Here, we demonstrate synthetic membraneless organelles in Escherichia coli termed transcriptionally engineered addressable RNA solvent droplets (TEARS). TEARS are assembled from RNA-binding protein recruiting domains fused to poly-CAG repeats that spontaneously drive liquid-liquid phase separation from the bulk cytoplasm. Targeting TEARS with fluorescent proteins revealed multilayered structures with composition and reaction robustness governed by non-equilibrium dynamics. We show that TEARS provide organelle-like bioprocess isolation for sequestering biochemical pathways, controlling metabolic branch points, buffering mRNA translation rates, and scaffolding protein-protein interactions. We anticipate TEARS to be a simple and versatile tool for spatially controlling E. coli biochemistry. Particularly, the modular design of TEARS enables applications without expression fine-tuning, simplifying the design-build-test cycle of bioengineering.
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Affiliation(s)
- Haotian Guo
- Université de Paris, INSERM U1284, Center for Research and Interdisciplinarity (CRI), 75006 Paris, France.
| | - Joseph C Ryan
- Université de Paris, INSERM U1284, Center for Research and Interdisciplinarity (CRI), 75006 Paris, France
| | - Xiaohu Song
- Université de Paris, INSERM U1284, Center for Research and Interdisciplinarity (CRI), 75006 Paris, France
| | - Adeline Mallet
- Ultrastructural BioImaging UTechS, C2RT, Institut Pasteur, 28 rue du Dr Roux, 75015 Paris, France
| | - Mengmeng Zhang
- Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Science, Shenzhen, China
| | - Victor Pabst
- Université de Paris, INSERM U1284, Center for Research and Interdisciplinarity (CRI), 75006 Paris, France
| | - Antoine L Decrulle
- Université de Paris, INSERM U1284, Center for Research and Interdisciplinarity (CRI), 75006 Paris, France
| | - Paulina Ejsmont
- Université de Paris, INSERM U1284, Center for Research and Interdisciplinarity (CRI), 75006 Paris, France
| | - Edwin H Wintermute
- Université de Paris, INSERM U1284, Center for Research and Interdisciplinarity (CRI), 75006 Paris, France
| | - Ariel B Lindner
- Université de Paris, INSERM U1284, Center for Research and Interdisciplinarity (CRI), 75006 Paris, France.
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14
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Improvement in Violacein Production by Utilizing Formic Acid to Induce Quorum Sensing in Chromobacterium violaceum. Antioxidants (Basel) 2022; 11:antiox11050849. [PMID: 35624712 PMCID: PMC9137503 DOI: 10.3390/antiox11050849] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 04/20/2022] [Accepted: 04/25/2022] [Indexed: 11/20/2022] Open
Abstract
Violacein has attracted increasing attention due to its various biological activities, such as antibacterial, antifungal, antioxidative, and antitumor effects. To improve violacein production, formic acid (FA) was added to a culture medium, which resulted in a 20% increase (1.02 g/L) compared to the no-FA-addition group (0.85 g/L). The use of a stirred-tank bioreactor system also improved violacein production (by 0.56 g/L). A quorum-sensing (QS)-related gene (cviI) was induced by FA treatment, which revealed that the mechanism induced by FA utilized regulation of the cviI gene to induce the vio gene cluster for violacein production. To analyze the antioxidative properties of the violacein produced, 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) scavenging tests were conducted, and results reveal that the values of the 50% inhibitory concentration (IC50) of DPPH and ABTS were 0.286 and 0.182 g/L, respectively. Violacein also showed strong inhibitory activity against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis). In summary, this study found that the addition of formic acid can promote QS of Chromobacterium violaceum, thereby promoting the synthesis of violacein. Subsequently, the promoting effect was also evaluated in a bioreactor system. These findings will be helpful in establishing an economically beneficial production model for violacein in future work.
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15
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Casas A, Bultelle M, Motraghi C, Kitney R. PASIV: A Pooled Approach-Based Workflow to Overcome Toxicity-Induced Design of Experiments Failures and Inefficiencies. ACS Synth Biol 2022; 11:1272-1291. [PMID: 35261238 PMCID: PMC8938949 DOI: 10.1021/acssynbio.1c00562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
We present here a
newly developed workflow—which we have
called PASIV—designed to provide a solution to a practical
problem with design of experiments (DoE) methodology: i.e., what can
be done if the scoping phase of the DoE cycle is severely hampered
by burden and toxicity issues (caused by either the metabolite or
an intermediary), making it unreliable or impossible to proceed to
the screening phase? PASIV—standing for pooled approach, screening,
identification, and visualization—was designed so the (viable)
region of interest can be made to appear through an interplay between
biology and software. This was achieved by combining multiplex construction
in a pooled approach (one-pot reaction) with a viability assay and
with a range of bioinformatics tools (including a novel construct
matching tool). PASIV was tested on the exemplar of the lycopene pathway—under
stressful constitutive expression—yielding a region of interest
with comparatively stronger producers.
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Affiliation(s)
- Alexis Casas
- Department of Bioengineering, Imperial College London, Exhibition Road, London SW7 2BX, United Kingdom
| | - Matthieu Bultelle
- Department of Bioengineering, Imperial College London, Exhibition Road, London SW7 2BX, United Kingdom
| | - Charles Motraghi
- Department of Bioengineering, Imperial College London, Exhibition Road, London SW7 2BX, United Kingdom
| | - Richard Kitney
- Department of Bioengineering, Imperial College London, Exhibition Road, London SW7 2BX, United Kingdom
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16
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Development of Methylorubrum extorquens AM1 as a promising platform strain for enhanced violacein production from co-utilization of methanol and acetate. Metab Eng 2022; 72:150-160. [PMID: 35301124 DOI: 10.1016/j.ymben.2022.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 02/16/2022] [Accepted: 03/10/2022] [Indexed: 11/21/2022]
Abstract
Violacein, a blue-violet compound with a wide range of beneficial bioactivities, is an attractive product for microbial production. Currently, violacein production has been demonstrated in several sugar heterotrophs through metabolic engineering; however, the cost of production remains an obstacle for business ventures. To address this issue, the development of host strains that can utilize inexpensive alternative substrates to reduce production costs would enable the commercialization of violacein. In this study, we engineered a facultative methylotroph, Methylorubrum extorquens AM1, to develop a methanol-based platform for violacein production. By optimizing expression vectors as well as inducer concentrations, 11.7 mg/L violacein production was first demonstrated using methanol as the sole substrate. Considering that unidentified bottlenecks for violacein biosynthesis in the shikimate pathway of M. extorquens AM1 would be difficult to address using generic metabolic engineering approaches, random mutagenesis and site-directed mutagenesis were implemented, and a 2-fold improvement in violacein production was achieved. Finally, by co-utilization of methanol and acetate, a remarkable enhancement of violacein production to 118 mg/L was achieved. Our results establish a platform strain for violacein production from non-sugar feedstocks, which may contribute to the development of an economically efficient large-scale fermentation system for violacein production.
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Kanekar S, Devasya RP. Growth-phase specific regulation of cviI/R based quorum sensing associated virulence factors in Chromobacterium violaceum by linalool, a monoterpenoid. World J Microbiol Biotechnol 2022; 38:23. [PMID: 34989882 DOI: 10.1007/s11274-021-03208-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 12/11/2021] [Indexed: 12/13/2022]
Abstract
Quorum sensing (QS)-dependent gene regulation in bacteria performs a vital role in synchronization of cell-density-dependent functions. In Chromobacterium violaceum QS-dependent cviI/R regulatory genes are activated during the mid- or late-exponential phase of growth. However, sufficient evidence is lacking on the role of QS inhibitors on gene regulation at different phases of growth. Hence, we report the role of linalool, a natural monoterpenoid on QS mediated gene regulation at different stages of growth in C. violaceum by performing biosensor, growth kinetic and gene expression studies. In vitro and in vivo studies were performed for establishing role of linalool in reducing the virulence and infection by using HEK-293 T cell lines and Caenorhabditis elegans models respectively. C. violaceum CV026 with C6-HSL was used as control. The results showed linalool to be a QS inhibitor with an estimated IC50 of 63 µg/mL for violacein inhibition. At this concentration the cell density difference (delta OD600) of 0.14 from the compound was observed indicating the quorum concentration. The expression of cviI/R was initiated at mid-log phase (~ 18 h) and reached the maximum at 36 h in control whereas in treatment it remained significantly downregulated at all time points. The expression of violacein biosynthetic genes vioA, vioC, vioD and vioE was also downregulated by linalool. Infection studies with linalool showed higher survival rates in HEK-293T cell lines and C. elegans compared to the infection control. Taken together, this study proves linalool to be a QS inhibitor capable of attenuation of QS by controlling the cell density through cviI/R downregulation at the early phase of growth and hence offering scope for its application for controlling infections.
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Affiliation(s)
- Saptami Kanekar
- Microbiology and Biotechnology Division, Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Deralakatte, Mangalore, Karnataka, 575018, India
| | - Rekha Punchappady Devasya
- Microbiology and Biotechnology Division, Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Deralakatte, Mangalore, Karnataka, 575018, India.
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18
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Anti-Pathogenic Properties of the Combination of a T3SS Inhibitory Halogenated Pyrrolidone with C-30 Furanone. Molecules 2021; 26:molecules26247635. [PMID: 34946717 PMCID: PMC8707098 DOI: 10.3390/molecules26247635] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/12/2021] [Accepted: 12/13/2021] [Indexed: 11/17/2022] Open
Abstract
Antimicrobial resistance is one of the current public health challenges to be solved. The World Health Organization (WHO) has urgently called for the development of strategies to expand the increasingly limited antimicrobial arsenal. The development of anti-virulence therapies is a viable option to counteract bacterial infections with the possibility of reducing the generation of resistance. Here we report on the chemical structures of pyrrolidones DEXT 1–4 (previously identified as furan derivatives) and their anti-virulence activity on Pseudomonas aeruginosa strains. DEXT 1–4 were shown to inhibit biofilm formation, swarming motility, and secretion of ExoU and ExoT effector proteins. Also, the anti-pathogenic property of DEXT-3 alone or in combination with furanone C-30 (quorum sensing inhibitor) or MBX-1641 (type III secretion system inhibitor) was analyzed in a model of necrosis induced by P. aeruginosa PA14. All treatments reduced necrosis; however, only the combination of C-30 50 µM with DEXT-3 100 µM showed significant inhibition of bacterial growth in the inoculation area and systemic dispersion. In conclusion, pyrrolidones DEXT 1–4 are chemical structures capable of reducing the pathogenicity of P. aeruginosa and with the potential for the development of anti-virulence combination therapies.
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Ahmed A, Ahmad A, Li R, AL-Ansi W, Fatima M, Mushtaq BS, Basharat S, Li Y, Bai Z. Recent Advances in Synthetic, Industrial and Biological Applications of Violacein and Its Heterologous Production. J Microbiol Biotechnol 2021; 31:1465-1480. [PMID: 34584039 PMCID: PMC9705886 DOI: 10.4014/jmb.2107.07045] [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: 07/27/2021] [Revised: 09/15/2021] [Accepted: 09/26/2021] [Indexed: 12/15/2022]
Abstract
Violacein, a purple pigment first isolated from a gram-negative coccobacillus Chromobacterium violaceum, has gained extensive research interest in recent years due to its huge potential in the pharmaceutic area and industry. In this review, we summarize the latest research advances concerning this pigment, which include (1) fundamental studies of its biosynthetic pathway, (2) production of violacein by native producers, apart from C. violaceum, (3) metabolic engineering for improved production in heterologous hosts such as Escherichia coli, Citrobacter freundii, Corynebacterium glutamicum, and Yarrowia lipolytica, (4) biological/pharmaceutical and industrial properties, (5) and applications in synthetic biology. Due to the intrinsic properties of violacein and the intermediates during its biosynthesis, the prospective research has huge potential to move this pigment into real clinical and industrial applications.
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Affiliation(s)
- Aqsa Ahmed
- School of Biotechnology, Jiangnan University, Wuxi 214122, P.R. China,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, P.R. China
| | - Abdullah Ahmad
- Department of Industrial Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Science and Technology, Islamabad 44000, Pakistan
| | - Renhan Li
- School of Biotechnology, Jiangnan University, Wuxi 214122, P.R. China,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, P.R. China
| | - Waleed AL-Ansi
- School of Food Science and Technology, State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, P.R. China,Department of Food Science and Technology, Faculty of Agriculture, Sana’a University, Sana’a, 725, Yemen
| | - Momal Fatima
- Department of Industrial Biotechnology, National Institute of Biotechnology and Genetic Engineering (NIBGE), Faisalabad 38000, Pakistan
| | - Bilal Sajid Mushtaq
- School of Food Science and Technology, State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, P.R. China
| | - Samra Basharat
- School of Biotechnology, Jiangnan University, Wuxi 214122, P.R. China
| | - Ye Li
- School of Biotechnology, Jiangnan University, Wuxi 214122, P.R. China,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, P.R. China,Corresponding authors Y. Li E-mail:
| | - Zhonghu Bai
- School of Biotechnology, Jiangnan University, Wuxi 214122, P.R. China,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, P.R. China,
Z. Bai Phone: +86510-85197983 Fax: +86510-85197983 E-mail:
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20
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Ramdass AC, Rampersad SN. Molecular signatures of Janthinobacterium lividum from Trinidad support high potential for crude oil metabolism. BMC Microbiol 2021; 21:287. [PMID: 34670489 PMCID: PMC8527658 DOI: 10.1186/s12866-021-02346-4] [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: 07/02/2021] [Accepted: 10/06/2021] [Indexed: 11/30/2022] Open
Abstract
Background Janthinobacterium lividum is considered to be a psychrotrophic bacterial species. For the first time in the literature, J. lividum strains were isolated from Trinidad presenting with atypical features - hydrocarbonoclastic and able to survive in a tropical environment. Methods Identification of the Trinidad strains was carried out through 16S rRNA phylogenetic analysis. Gene-specific primers were designed to target the VioA which encodes violacein pigment and the EstA/B gene which encodes secreted extracellular lipase. Bioinformatics analyses were carried out on the nucleotide and amino acid sequences of VioA and EstA/B genes of the Trinidad Janthinobacterium strains to assess functionality and phylogenetic relatedness to other Janthinobacterium sequences specifically and more broadly, to other members of the Oxalobacteraceae family of betaproteobacteria. Results 16S rRNA confirmed the identity of the Trinidad strains as J. lividum and resolved three of the Trinidad strains at the intra-specific level. Typical motility patterns of this species were recorded. VioAp sequences were highly conserved, however, synonymous substitutions located outside of the critical sites for enzyme function were detected for the Trinidad strains. Comparisons with PDB 6g2p model from aa231 to aa406 further indicated no functional disruption of the VioA gene of the Trinidad strains. Phylogeny of the VioA protein sequences inferred placement of all J. lividum taxa into a highly supported species-specific clade (bs = 98%). EstA/Bp sequences were highly conserved, however, synonymous substitutions were detected that were unique to the Trinidad strains. Phylogenetic inference positioned the Trinidad consensus VioA and EstA protein sequences in a clearly distinct branch. Conclusions The findings showed that the primary sequence of VioAp and EstA/Bp were unique to the Trinidad strains and these molecular signatures were reflected in phylogenetic inference. Our results supported chemotaxis, possible elective inactivation of VioA gene expression and secreted lipase activity as survival mechanisms of the Trinidad strains in petrogenic conditions. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02346-4.
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Affiliation(s)
- Amanda C Ramdass
- Biochemistry Research Lab (Rm216), Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Sephra N Rampersad
- Biochemistry Research Lab (Rm216), Department of Life Sciences, Faculty of Science and Technology, The University of the West Indies, St. Augustine, Trinidad and Tobago.
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21
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Durán N, Nakazato G, Durán M, Berti IR, Castro GR, Stanisic D, Brocchi M, Fávaro WJ, Ferreira-Halder CV, Justo GZ, Tasic L. Multi-target drug with potential applications: violacein in the spotlight. World J Microbiol Biotechnol 2021; 37:151. [PMID: 34398340 DOI: 10.1007/s11274-021-03120-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 08/02/2021] [Indexed: 11/28/2022]
Abstract
The aim of the current review is to address updated research on a natural pigment called violacein, with emphasis on its production, biological activity and applications. New information about violacein's action mechanisms as antitumor agent and about its synergistic action in drug delivery systems has brought new alternatives for anticancer therapy. Thus, violacein is introduced as reliable drug capable of overcoming at least three cancer hallmarks, namely: proliferative signaling, cell death resistance and metastasis. In addition, antimicrobial effects on several microorganisms affecting humans and other animals turn violacein into an attractive drug to combat resistant pathogens. Emphasis is given to effects of violacein combined with different agents, such as antibiotics, anticancer agents and nanoparticles. Although violacein is well-known for many decades, it remains an attractive compound. Thus, research groups have been making continuous effort to help improving its production in recent years, which can surely enable its pharmaceutical and chemical application as multi-task compound, even in the cosmetics and food industries.
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Affiliation(s)
- Nelson Durán
- Laboratory of Urogenital Carcinogenesis and Immunotherapy, Department of Structural and Functional Biology, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil. .,Nanomedicine Research Unit (Nanomed), Center for Natural and Human Sciences (CCNH), Universidade Federal do ABC (UFABC), Santo André, SP, Brazil.
| | - Gerson Nakazato
- Laboratory of Basic and Applied Bacteriology, Department of Microbiology, Biology Sciences Center, Universidade Estadual de Londrina (UEL), Londrina, PR, Brazil
| | - Marcela Durán
- Laboratory of Urogenital Carcinogenesis and Immunotherapy, Department of Structural and Functional Biology, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil.,Nanomedicine Research Unit (Nanomed), Center for Natural and Human Sciences (CCNH), Universidade Federal do ABC (UFABC), Santo André, SP, Brazil
| | - Ignasio R Berti
- Nanobiomaterials Laboratory, Department of Chemistry, School of Sciences, Institute of Applied Biotechnology CINDEFI (UNLPCONICET, CCT La Plata),, Universidad Nacional de La Plata, La Plata, Argentina
| | - Guillermo R Castro
- Nanobiomaterials Laboratory, Department of Chemistry, School of Sciences, Institute of Applied Biotechnology CINDEFI (UNLPCONICET, CCT La Plata),, Universidad Nacional de La Plata, La Plata, Argentina
| | - Danijela Stanisic
- Biological Chemistry Laboratory, Institute of Chemistry, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Marcelo Brocchi
- Laboratory of Tropical Diseases, Department of Genetic, Evolution and Bioagents , Biology Institute, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Wagner J Fávaro
- Laboratory of Urogenital Carcinogenesis and Immunotherapy, Department of Structural and Functional Biology, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Carmen V Ferreira-Halder
- Departamento de Bioquímica e Biologia Tecidual, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Giselle Z Justo
- Departamento de Ciências Farmacêuticas (Campus Diadema) e Departamento de Bioquímica (Campus São Paulo), Universidade Federal de São Paulo (UNIFESP), 3 de Maio, 100, São Paulo, SP, 04044-020, Brazil.
| | - Ljubica Tasic
- Biological Chemistry Laboratory, Institute of Chemistry, Universidade Estadual de Campinas, Campinas, SP, Brazil
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22
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Ahmed SO, Zedan HH, Ibrahim YM. Quorum sensing inhibitory effect of bergamot oil and aspidosperma extract against Chromobacterium violaceum and Pseudomonas aeruginosa. Arch Microbiol 2021; 203:4663-4675. [PMID: 34175964 DOI: 10.1007/s00203-021-02455-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/21/2021] [Accepted: 06/21/2021] [Indexed: 10/21/2022]
Abstract
Quorum sensing (QS) represents a major target for reducing bacterial pathogenicity and antibiotic resistance. This study identifies bergamot and aspidosperma as new potential sources of anti-QS agents. We investigated the anti-QS activity of plant materials on both Chromobacterium violaceum and Pseudomonas aeruginosa. Initially, we determined the minimum inhibitory concentrations (MICs) of plant materials using a broth microdilution method. Subsequently, we tested the effect of sub-MIC concentrations on QS-regulated traits and virulence factors production in test bacteria. Results revealed that bergamot and aspidosperma inhibited the ability of C. violaceum to produce violacein. Other QS-controlled phenotypes of C. violaceum, namely chitinolytic activity, motility, and biofilm formation, were also reduced by both plant materials. Moreover, QS-linked traits of P. aeruginosa were also reduced. Bergamot inhibited swarming but not swimming motility, while aspidosperma diminished both motility types in P. aeruginosa. Both plant materials also demonstrated antibiofilm activity and inhibited the production of protease and pyocyanin in P. aeruginosa. Furthermore, we tested the anti-QS effect of plant materials on the transcriptional level using RT-qPCR. Bergamot dramatically downregulated the C. violaceum autoinducer synthase gene cviI and the vioB gene involved in violacein biosynthesis, confirming the phenotypic observation on its anti-QS activity. Aspidosperma also reduced the expression of cviI and vioB but less drastically than bergamot. In P. aeruginosa, downregulation in the transcripts of the QS genes lasI, lasR, rhlI, and rhlR was also achieved by bergamot and aspidosperma. Therefore, data in the present study suggest the usefulness of bergamot and aspidosperma as sources of antivirulence agents.
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Affiliation(s)
- Sarah Omar Ahmed
- Department of Microbiology, General Division of Basic Medical Sciences, Egyptian Drug Authority (EDA), Formerly National Organization for Drug Control and Research (NODCAR), Giza, 12611, Egypt
| | - Hamdallah Hafez Zedan
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Yasser Musa Ibrahim
- Department of Microbiology, General Division of Basic Medical Sciences, Egyptian Drug Authority (EDA), Formerly National Organization for Drug Control and Research (NODCAR), Giza, 12611, Egypt.
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23
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Ahearne A, Albataineh H, Dowd SE, Stevens DC. Assessment of Evolutionary Relationships for Prioritization of Myxobacteria for Natural Product Discovery. Microorganisms 2021; 9:microorganisms9071376. [PMID: 34202719 PMCID: PMC8307915 DOI: 10.3390/microorganisms9071376] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/03/2021] [Accepted: 06/21/2021] [Indexed: 02/06/2023] Open
Abstract
Discoveries of novel myxobacteria have started to unveil the potentially vast phylogenetic diversity within the family Myxococcaceae and have brought about an updated approach to myxobacterial classification. While traditional approaches focused on morphology, 16S gene sequences, and biochemistry, modern methods including comparative genomics have provided a more thorough assessment of myxobacterial taxonomy. Herein, we utilize long-read genome sequencing for two myxobacteria previously classified as Archangium primigenium and Chondrococcus macrosporus, as well as four environmental myxobacteria newly isolated for this study. Average nucleotide identity and digital DNA-DNA hybridization scores from comparative genomics suggest previously classified as A. primigenium to instead be a novel member of the genus Melittangium, C. macrosporus to be a potentially novel member of the genus Corallococcus with high similarity to Corallococcus exercitus, and the four isolated myxobacteria to include another novel Corallococcus species, a novel Pyxidicoccus species, a strain of Corallococcus exiguus, and a potentially novel Myxococcus species with high similarity to Myxococcus stipitatus. We assess the biosynthetic potential of each sequenced myxobacterium and suggest that genus-level conservation of biosynthetic pathways support our preliminary taxonomic assignment. Altogether, we suggest that long-read genome sequencing benefits the classification of myxobacteria and improves determination of biosynthetic potential for prioritization of natural product discovery.
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Affiliation(s)
- Andrew Ahearne
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA; (A.A.); (H.A.)
| | - Hanan Albataineh
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA; (A.A.); (H.A.)
| | - Scot E. Dowd
- MR DNA, Molecular Research LP, Shallowater, TX 79363, USA;
| | - D. Cole Stevens
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA; (A.A.); (H.A.)
- Correspondence: ; Tel.: +1-662-915-5730
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24
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Chamberlain CA, Hatch M, Garrett TJ. Extracellular Vesicle Analysis by Paper Spray Ionization Mass Spectrometry. Metabolites 2021; 11:metabo11050308. [PMID: 34065030 PMCID: PMC8151837 DOI: 10.3390/metabo11050308] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/23/2021] [Accepted: 05/06/2021] [Indexed: 12/29/2022] Open
Abstract
Paper spray ionization mass spectrometry (PSI-MS) is a direct MS analysis technique with several reported bacterial metabolomics applications. As with most MS-based bacterial studies, all currently reported PSI-MS bacterial analyses have focused on the chemical signatures of the cellular unit. One dimension of the bacterial metabolome that is often lost in such analyses is the exometabolome (extracellular metabolome), including secreted metabolites, lipids, and peptides. A key component of the bacterial exometabolome that is gaining increased attention in the microbiology and biomedical communities is extracellular vesicles (EVs). These excreted structures, produced by cells in all domains of life, contain a variety of biomolecules responsible for a wide array of cellular functions, thus representing a core component of the bacterial secreted metabolome. Although previously examined using other MS approaches, no reports currently exist for a PSI-MS analysis of bacterial EVs, nor EVs from any other organism (exosomes, ectosomes, etc.). PSI-MS holds unique analytical strengths over other commonly used MS platforms and could thus provide an advantageous approach to EV metabolomics. To address this, we report a novel application representing, to our knowledge, the first PSI-MS analysis of EVs from any organism (using the human gut resident Oxalobacter formigenes as the experimental model, a bacterium whose EVs were never previously investigated). In this report, we show how we isolated and purified EVs from bacterial culture supernatant by EV-specific affinity chromatography, confirmed and characterized these vesicles by nanoparticle tracking analysis, analyzed the EV isolate by PSI-MS, and identified a panel of EV-derived metabolites, lipids, and peptides. This work serves as a pioneering study in the field of MS-based EV analysis and provides a new, rapid, sensitive, and economical approach to EV metabolomics.
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Mion S, Carriot N, Lopez J, Plener L, Ortalo-Magné A, Chabrière E, Culioli G, Daudé D. Disrupting quorum sensing alters social interactions in Chromobacterium violaceum. NPJ Biofilms Microbiomes 2021; 7:40. [PMID: 33888726 PMCID: PMC8062528 DOI: 10.1038/s41522-021-00211-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 03/25/2021] [Indexed: 12/18/2022] Open
Abstract
Quorum sensing (QS) is a communication system used by bacteria to coordinate a wide panel of biological functions in a cell density-dependent manner. The Gram-negative Chromobacterium violaceum has previously been shown to use an acyl-homoserine lactone (AHL)-based QS to regulate various behaviors, including the production of proteases, hydrogen cyanide, or antimicrobial compounds such as violacein. By using combined metabolomic and proteomic approaches, we demonstrated that QS modulates the production of antimicrobial and toxic compounds in C. violaceum ATCC 12472. We provided the first evidence of anisomycin antibiotic production by this strain as well as evidence of its regulation by QS and identified new AHLs produced by C. violaceum ATCC 12472. Furthermore, we demonstrated that targeting AHLs with lactonase leads to major QS disruption yielding significant molecular and phenotypic changes. These modifications resulted in drastic changes in social interactions between C. violaceum and a Gram-positive bacterium (Bacillus cereus), a yeast (Saccharomyces cerevisiae), immune cells (murine macrophages), and an animal model (planarian Schmidtea mediterranea). These results underscored that AHL-based QS plays a key role in the capacity of C. violaceum to interact with micro- and macroorganisms and that quorum quenching can affect microbial population dynamics beyond AHL-producing bacteria and Gram-negative bacteria.
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Affiliation(s)
- Sonia Mion
- Aix Marseille University, Institut de Recherche pour le Développement, Assistance Publique - Hôpitaux de Marseille, Microbes Evolution Phylogeny and Infections, Institut Hospitalo-Universitaire-Méditerranée Infection, Marseille, France
| | | | | | | | | | - Eric Chabrière
- Aix Marseille University, Institut de Recherche pour le Développement, Assistance Publique - Hôpitaux de Marseille, Microbes Evolution Phylogeny and Infections, Institut Hospitalo-Universitaire-Méditerranée Infection, Marseille, France.
| | - Gérald Culioli
- Université de Toulon, MAPIEM, Toulon, France. .,Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale, UMR CNRS-IRD, Avignon Université, Aix-Marseille Université, Avignon, France.
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Park H, Park S, Yang YH, Choi KY. Microbial synthesis of violacein pigment and its potential applications. Crit Rev Biotechnol 2021; 41:879-901. [PMID: 33730942 DOI: 10.1080/07388551.2021.1892579] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Violacein is a pigment synthesized by Gram-negative bacteria such as Chromobacterium violaceum. It has garnered significant interest owing to its unique physiological and biological activities along with its synergistic effects with various antibiotics. In addition to C. violaceum, several microorganisms, including: Duganella sp., Pseudoalteromonas sp., Iodobacter sp., and Massilia sp., are known to produce violacein. Along with the identification of violacein-producing strains, the genetic regulation, quorum sensing mechanism, and sequence of the vio-operon involved in the biosynthesis of violacein have been elucidated. From an engineering perspective, the heterologous production of violacein using the genetically engineered Escherichia coli or Citrobacter freundii host has also been attempted. Genetic engineering of host cells involves the heterologous expression of genes involved in the vio operon and the optimization of metabolic pathways and gene regulation. Further, the crystallography of VioD and VioE was revealed, and mass production by enzyme engineering has been accelerated. In this review, we highlight the biologically assisted end-use applications of violacein (such as functional fabric development, nanoparticles, functional polymer composites, and sunscreen ingredients) and violacein activation mechanisms, production strains, and the results of mass production with engineered methods. The prospects for violacein research and engineering applications have also been discussed.
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Affiliation(s)
- HyunA Park
- Department of Environmental Engineering, College of Engineering, Ajou University, Suwon, South Korea
| | - SeoA Park
- Department of Environmental Engineering, College of Engineering, Ajou University, Suwon, South Korea
| | - Yung-Hun Yang
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul, South Korea
| | - Kwon-Young Choi
- Department of Environmental Engineering, College of Engineering, Ajou University, Suwon, South Korea.,Department of Environmental and Safety Engineering, College of Engineering, Ajou University, Suwon, South Korea
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Durán N, Fávaro WJ, Brocchi M, Justo GZ, Castro GR, Durán M, Nakazato G. Patents on Violacein: A Compound with Great Diversity of Biological Activities and Industrial Potential. Recent Pat Biotechnol 2020; 15:102-111. [PMID: 33349223 DOI: 10.2174/2213476x07666201221111655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/15/2020] [Accepted: 11/16/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND This review outlines to envisage the current impact of violacein-derivative materials in several technological areas through patents. METHODS A comprehensive examination up to day patent databases on violacein demonstrated the relevance of this pigment, as well as the pertinent topics related to its technological development in order to obtain adaptable new pharmaceuticals, cosmetics and new quality fiber materials, together with others applications of violacein in different areas. RESULTS At present time, there is no efficient and economical feasible technique for violacein preparation at industrial scale. Many attempts have been developed but none have achieved the big challenge of being effective and inexpensive process. However, some potential applications of violacein in fields like biomedicine make the pigment worth to continuous the investigations. Particularly, violacein patents covering from biosynthesis to different applications were reported recently. CONCLUSION As unique pigment, violacein has been used in distinct areas of specialties, such as in medical and industrial fields. Then, this review through patents provides an update on violacein innovations useful for researchers working in an expandable and interesting field of biotechnology with natural pigments.
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Affiliation(s)
- Nelson Durán
- Laboratory of Urogenital Carcinogenesis and Immunotherapy, Biology Institute, Department of Structural and Functional Biology, University of Campinas,Campinas, SP. Brazil
| | - Wagner J Fávaro
- Laboratory of Urogenital Carcinogenesis and Immunotherapy, Biology Institute, Department of Structural and Functional Biology, University of Campinas,Campinas, SP. Brazil
| | - Marcelo Brocchi
- Laboratory of Tropical Diseases, Institute of Biology, Department of Genetic, Evolution, Microbiology and Immunology. University of Campinas, Campinas, SP. Brazil
| | - Giselle Z Justo
- Department of Pharmaceutical Sciences and Department of Biochemistry, Federal University of São Paulo (UNIFESP). Brazil
| | - Guillermo R Castro
- Nanobiomaterials Laboratory, Institute of Applied Biotechnology CINDEFI (UNLP-CONICET, CCT La Plata), Department of Chemistry, School of Sciences, Universidad Nacional de La Plata, La Plata. Argentina
| | - Marcela Durán
- Laboratory of Urogenital Carcinogenesis and Immunotherapy, Biology Institute, Department of Structural and Functional Biology, University of Campinas,Campinas, SP. Brazil
| | - Gerson Nakazato
- Laboratory of Basic and Applied Bacteriology, Department of Microbiology, Biology Sciences Center, Londrina State University (UEL), Londrina. Brazil
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Ibrahim YM, Abouwarda AM, Omar FA. Effect of kitasamycin and nitrofurantoin at subinhibitory concentrations on quorum sensing regulated traits of Chromobacterium violaceum. Antonie van Leeuwenhoek 2020; 113:1601-1615. [PMID: 32889593 DOI: 10.1007/s10482-020-01467-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 08/25/2020] [Indexed: 12/12/2022]
Abstract
Quorum sensing (QS) is a mechanism of intercellular communication in bacteria that received substantial attention as alternate strategy for combating bacterial resistance and the development of new anti-infective agents. The present investigation reports on the assessment of using subinhibitory concentrations of antibiotics for the inhibition of QS-regulated phenotypes in Chromobacterium violaceum. Primarily, the minimum inhibitory concentrations of a series of antibiotics were determined by a microdilution method. Subsequently, the inhibitory effects of selected antibiotics on QS-regulated traits, namely violacein and chitinase production, biofilm formation and motility were evaluated using C. violaceum CV026 and C. violaceum ATCC 12472. Results revealed that kitasamycin and nitrofurantoin exhibited the highest quorum sensing inhibitory (QSI) activity. The amount of violacein produced by C. violaceum was significantly reduced in the presence of either kitasamycin or nitrofurantoin. Moreover, the chitinolytic activity, biofilm formation, and motility were also impaired in kitasamycin or nitrofurantoin-treated cultures. We further confirmed QSI effects at the molecular level using molecular docking and real-time quantitative polymerase chain reaction (RT-qPCR). Results of molecular docking suggested that both antibiotics can interact with CviR transcriptional regulator of C. violaceum. Furthermore, RT-qPCR revealed the suppressive effect of kitasamycin and nitrofurantoin on five genes under the control of the CviI/CviR system: cviI, cviR, vioB, vioC, and vioD. Giving that kitasamycin and nitrofurantoin are being safely used for decades, this study emphasizes their potential application as antivirulence agents to disarm resistant bacterial strains, making their removal an easier task for the immune system or for another antibacterial agent.
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Affiliation(s)
- Yasser Musa Ibrahim
- Department of Microbiology, General Division of Basic Medical Sciences, National Organization for Drug Control and Research (NODCAR), Giza, 12611, Egypt.
| | - Ahmed Megahed Abouwarda
- Department of Microbiology, General Division of Basic Medical Sciences, National Organization for Drug Control and Research (NODCAR), Giza, 12611, Egypt
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Modolon F, Barno AR, Villela HDM, Peixoto RS. Ecological and biotechnological importance of secondary metabolites produced by coral-associated bacteria. J Appl Microbiol 2020; 129:1441-1457. [PMID: 32627318 DOI: 10.1111/jam.14766] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/20/2020] [Accepted: 06/28/2020] [Indexed: 12/16/2022]
Abstract
Symbiotic relationships between corals and their associated micro-organisms are essential to maintain host homeostasis. Coral-associated bacteria (CAB) can have different beneficial roles in the coral metaorganism, such as metabolizing essential nutrients for the coral host and protecting the coral from pathogens. Many CAB exert these functions via secondary metabolites, which include antibacterial, antifouling, antitumour, antiparasitic and antiviral compounds. This review describes how analysis of CAB has led to the discovery of secondary metabolites with potential biotechnological applications. The most commonly found types of secondary metabolites, antimicrobial and antibiofilm compounds, are emphasized and described. Recently developed methods that can be applied to enhance the culturing of CAB from shallow-water reefs and the less-studied deep-sea coral reefs are also discussed. Last, we suggest how the combined use of meta-omics and innovative growth-diffusion techniques can vastly improve the discovery of novel compounds in coral environments.
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Affiliation(s)
- F Modolon
- Department of Microbiology, Paulo de Góes Microbiology Institute, Federal University of Rio De Janeiro, Rio de Janeiro, RJ, Brazil
| | - A R Barno
- Department of Microbiology, Paulo de Góes Microbiology Institute, Federal University of Rio De Janeiro, Rio de Janeiro, RJ, Brazil
| | - H D M Villela
- Department of Microbiology, Paulo de Góes Microbiology Institute, Federal University of Rio De Janeiro, Rio de Janeiro, RJ, Brazil
| | - R S Peixoto
- Department of Microbiology, Paulo de Góes Microbiology Institute, Federal University of Rio De Janeiro, Rio de Janeiro, RJ, Brazil.,IMAM-AquaRio - Rio de Janeiro Aquarium Research Center, Rio de Janeiro, RJ, Brazil
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Alem D, Marizcurrena JJ, Saravia V, Davyt D, Martinez-Lopez W, Castro-Sowinski S. Production and antiproliferative effect of violacein, a purple pigment produced by an Antarctic bacterial isolate. World J Microbiol Biotechnol 2020; 36:120. [DOI: 10.1007/s11274-020-02893-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 07/11/2020] [Indexed: 12/22/2022]
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Kruger A. Functional Redundancy of Batrachochytrium dendrobatidis Inhibition in Bacterial Communities Isolated from Lithobates clamitans Skin. MICROBIAL ECOLOGY 2020; 79:231-240. [PMID: 31165187 DOI: 10.1007/s00248-019-01387-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/29/2019] [Indexed: 06/09/2023]
Abstract
The cutaneous microbial community can influence the health of amphibians exposed to Batrachochytrium dendrobatidis (Bd), a fungal pathogen that has contributed to recent amphibian declines. Resistance to Bd in amphibian populations is correlated with the presence of anti-Bd cutaneous microbes, which confer disease resistance by inhibiting Bd growth. I aimed to determine if green frogs (Lithobates clamitans), an abundant and widely distributed species in New Jersey, harbored bacteria that inhibit Bd and whether the presence and identity of these microbes varied among sites. I used in vitro challenge assays to determine if bacteria isolated from green frog skin could inhibit or enhance the growth of Bd. I found that green frogs at all sites harbored anti-Bd bacteria. However, there were differences in Bd inhibition capabilities among bacterial isolates identified as the same operational taxonomic unit (OTU), lending support to the idea that phylogenetic relatedness does not always predict Bd inhibition status. Additionally, anti-Bd bacterial richness did not vary by site, but the composition of anti-Bd bacterial taxa was distinct at each site. This suggests that there is functional redundancy of Bd inhibition across unique communities of anti-Bd symbionts found on frogs at different sites. These findings highlight the need to better elucidate the structure-function relationship of microbiomes and their role in disease resistance.
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Affiliation(s)
- Ariel Kruger
- Graduate Program in Ecology and Evolution, Department of Ecology, Evolution, and Natural Resources, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ, 08901, USA.
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Ellis GA, Klein WP, Lasarte-Aragonés G, Thakur M, Walper SA, Medintz IL. Artificial Multienzyme Scaffolds: Pursuing in Vitro Substrate Channeling with an Overview of Current Progress. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02413] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Gregory A. Ellis
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - William P. Klein
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- National Research Council, Washington, D.C. 20001, United States
| | - Guillermo Lasarte-Aragonés
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- College of Science, George Mason University, Fairfax, Virginia 22030, United States
| | - Meghna Thakur
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
- College of Science, George Mason University, Fairfax, Virginia 22030, United States
| | - Scott A. Walper
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Igor L. Medintz
- Center for Bio/Molecular Science and Engineering, Code 6900, U.S. Naval Research Laboratory, Washington, D.C. 20375, United States
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The Bacterial Product Violacein Exerts an Immunostimulatory Effect Via TLR8. Sci Rep 2019; 9:13661. [PMID: 31541142 PMCID: PMC6754391 DOI: 10.1038/s41598-019-50038-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 07/19/2019] [Indexed: 12/28/2022] Open
Abstract
Violacein, an indole-derived, purple-colored natural pigment isolated from Chromobacterium violaceum has shown multiple biological activities. In this work, we studied the effect of violacein in different immune cell lines, namely THP-1, MonoMac 6, ANA-1, Raw 264.7 cells, as well as in human peripheral blood mononuclear cells (PBMCs). A stimulation of TNF-α production was observed in murine macrophages (ANA-1 and Raw 264.7), and in PBMCs, IL-6 and IL-1β secretion was detected. We obtained evidence of the molecular mechanism of activation by determining the mRNA expression pattern upon treatment with violacein in Raw 264.7 cells. Incubation with violacein caused activation of pathways related with an immune and inflammatory response. Our data utilizing TLR-transfected HEK-293 cells indicate that violacein activates the human TLR8 (hTLR8) receptor signaling pathway and not human TLR7 (hTLR7). Furthermore, we found that the immunostimulatory effect of violacein in PBMCs could be suppressed by the specific hTLR8 antagonist, CU-CPT9a. Finally, we studied the interaction of hTLR8 with violacein in silico and obtained evidence that violacein could bind to hTLR8 in a similar fashion to imidazoquinoline compounds. Therefore, our results indicate that violacein may have some potential in contributing to future immune therapy strategies.
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Isolation and characterization of violacein from an Antarctic Iodobacter: a non-pathogenic psychrotolerant microorganism. Extremophiles 2019; 24:43-52. [DOI: 10.1007/s00792-019-01111-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 06/17/2019] [Indexed: 10/26/2022]
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Deyell M, Ameta S, Nghe P. Large scale control and programming of gene expression using CRISPR. Semin Cell Dev Biol 2019; 96:124-132. [PMID: 31181342 DOI: 10.1016/j.semcdb.2019.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 05/14/2019] [Indexed: 12/22/2022]
Abstract
The control of gene expression in cells and organisms allows to unveil gene to function relationships and to reprogram biological responses. Several systems, such as Zinc fingers, TALE (Transcription activator-like effectors), and siRNAs (small-interfering RNAs), have been exploited to achieve this. However, recent advances in Clustered Regularly Interspaced Short Palindromic Repeats and Cas9 (CRISPR-Cas9) have overshadowed them due to high specificity, compatibility with many different organisms, and design flexibility. In this review we summarize state-of-the art for CRISPR-Cas9 technology for large scale gene perturbation studies, including single gene and multiple genes knock-out, knock-down, knock-up libraries, and their associated screening assays. We feature in particular the combination of these methods with single-cell transcriptomics approaches. Finally, we highlight the application of CRISPR-Cas9 systems in building synthetic circuits that can be interfaced with gene networks to control cellular states.
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Affiliation(s)
- Matthew Deyell
- Laboratoire de Biochimie, CNRS UMR8231, Chimie Biologie Innovation, PSL Research University, ESPCI Paris, 10 Rue Vauquelin, 75005, Paris, France
| | - Sandeep Ameta
- Laboratoire de Biochimie, CNRS UMR8231, Chimie Biologie Innovation, PSL Research University, ESPCI Paris, 10 Rue Vauquelin, 75005, Paris, France
| | - Philippe Nghe
- Laboratoire de Biochimie, CNRS UMR8231, Chimie Biologie Innovation, PSL Research University, ESPCI Paris, 10 Rue Vauquelin, 75005, Paris, France.
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Pauer H, Hardoim CCP, Teixeira FL, Miranda KR, Barbirato DDS, de Carvalho DP, Antunes LCM, Leitão ÁADC, Lobo LA, Domingues RMCP. Impact of violacein from Chromobacterium violaceum on the mammalian gut microbiome. PLoS One 2018; 13:e0203748. [PMID: 30212521 PMCID: PMC6136722 DOI: 10.1371/journal.pone.0203748] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 08/20/2018] [Indexed: 12/03/2022] Open
Abstract
Violacein is a violet pigment produced by Chromobacterium violaceum that possesses several functions such as antibacterial, antiviral, antifungal, and antioxidant activities. The search for potential compounds and therapies that may interfere with and modulate the gut microbial consortia without causing severe damage and increased resistance is important for the treatment of inflammatory, allergic, and metabolic diseases. The aim of the present work was to evaluate the ability of violacein to change microbial patterns in the mammalian gut by favoring certain groups over the others in order to be used as a therapy for diseases associated with changes in the intestinal microflora. To do this, we used male Wistar rats, and administered violacein orally, in low (50 μg/ml) and high (500 μg/ml) doses for a month. Initially, the changes in the microbial diversity were observed by DGGE analyses that showed that the violacein significantly affects the gut microbiota of the rats. Pyrosequencing of 16S rDNA was then employed using a 454 GS Titanium platform, and the results demonstrated that higher taxonomic richness was observed with the low violacein treatment group, followed by the control group and high violacein treatment group. Modulation of the microbiota at the class level was observed in the low violacein dose, where Bacilli and Clostridia (Firmicutes) were found as dominant. For the high violacein dose, Bacilli followed by Clostridia and Actinobacteria were present as the major components. Further analyses are crucial for a better understanding of how violacein affects the gut microbiome and whether this change would be beneficial to the host, providing a framework for the development of alternative treatment strategies for intestinal diseases using this compound.
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Affiliation(s)
- Heidi Pauer
- Laboratório de Biologia de Anaeróbios, Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | - Cristiane Cassiolato Pires Hardoim
- Laboratório de Interação Hospedeiro-Microbiota, Instituto de Biociências, Universidade Estadual Paulista, Campus do Litoral Paulista, São Vicente, SP, Brazil
| | - Felipe Lopes Teixeira
- Laboratório de Biologia de Anaeróbios, Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Karla Rodrigues Miranda
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Campus Macaé, Macaé, RJ, Brazil
| | | | - Denise Pires de Carvalho
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro–Rio de Janeiro, Brazil
| | - Luis Caetano Martha Antunes
- Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Inovação em Doenças de Populações Negligenciadas, Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil
| | | | - Leandro Araujo Lobo
- Laboratório de Biologia de Anaeróbios, Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- * E-mail:
| | - Regina Maria Cavalcanti Pilotto Domingues
- Laboratório de Biologia de Anaeróbios, Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Immanuel SRC, Banerjee D, Rajankar MP, Raghunathan A. Integrated constraints based analysis of an engineered violacein pathway in Escherichia coli. Biosystems 2018; 171:10-19. [PMID: 30008425 DOI: 10.1016/j.biosystems.2018.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/05/2018] [Accepted: 06/15/2018] [Indexed: 12/20/2022]
Abstract
Strategies towards optimal violacein biosynthesis, a potential drug molecule, need systems level coordination of enzymatic activities of individual genes in a multigene operon vioABCDE. Constraints-based flux balance analysis of an extended iAF1260 model (iAF1260vio) with a reconstructed violacein module predicted growth and violacein yields in Escherichia coli accurately. Shadow price (SP) analysis identified tryptophan metabolism and NADPH as limiting. Increased tryptophan levels in Δpgi & ΔpheA were validated using in silico gene deletion analysis. Phenotypic phase plane (PhPP) analysis highlighted sensitivity between tryptophan and NADPH for violacein synthesis at molar growth yields. A synthetic VioABCDE operon (SYNO) sequence was designed to maximize Codon Adaptive Index (CAI: 0.9) and tune translation initiation rates (TIR: 2-50 fold higher) in E. coli. All pSYN E. coli transformants produced higher violacein, with a maximum six-fold increase in yields. The rational design E. coli: ΔpheA SYN: gave the highest violacein titers (33.8 mg/l). Such integrated approaches targeting multiple molecular hierarchies in the cell can be extended further to increase violacein yields.
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Affiliation(s)
| | - Deepanwita Banerjee
- Chemical Engineering Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India
| | - Mayooreshwar P Rajankar
- Chemical Engineering Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India
| | - Anu Raghunathan
- Chemical Engineering Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India.
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luxR Homolog-Linked Biosynthetic Gene Clusters in Proteobacteria. mSystems 2018; 3:mSystems00208-17. [PMID: 29600287 PMCID: PMC5872303 DOI: 10.1128/msystems.00208-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 02/23/2018] [Indexed: 02/06/2023] Open
Abstract
Bacteria biosynthesize specialized metabolites with a variety of ecological functions, including defense against other microbes. Genes that code for specialized metabolite biosynthetic enzymes are frequently clustered together. These BGCs are often regulated by a transcription factor encoded within the cluster itself. These pathway-specific regulators respond to a signal or indirectly through other means of environmental sensing. Many specialized metabolites are not produced under laboratory growth conditions, and one reason for this issue is that laboratory growth media lack environmental cues necessary for BGC expression. Here, we report a bioinformatics study that reveals that BGCs are frequently linked to genes coding for LuxR family QS-responsive transcription factors in the phylum Proteobacteria. The products of these luxR homolog-associated gene clusters may serve as a practical source of bioactive metabolites. Microbes are a major source of antibiotics, pharmaceuticals, and other bioactive compounds. The production of many specialized microbial metabolites is encoded in biosynthetic gene clusters (BGCs). A challenge associated with natural product discovery is that many BGCs are not expressed under laboratory growth conditions. Here we report a genome-mining approach to discover BGCs with luxR-type quorum sensing (QS) genes, which code for regulatory proteins that control gene expression. Our results show that BGCs linked to genes coding for LuxR-like proteins are widespread in Proteobacteria. In addition, we show that associations between luxR homolog genes and BGCs have evolved independently many times, with functionally diverse gene clusters. Overall, these clusters may provide a source of new natural products for which there is some understanding about how to elicit production. IMPORTANCE Bacteria biosynthesize specialized metabolites with a variety of ecological functions, including defense against other microbes. Genes that code for specialized metabolite biosynthetic enzymes are frequently clustered together. These BGCs are often regulated by a transcription factor encoded within the cluster itself. These pathway-specific regulators respond to a signal or indirectly through other means of environmental sensing. Many specialized metabolites are not produced under laboratory growth conditions, and one reason for this issue is that laboratory growth media lack environmental cues necessary for BGC expression. Here, we report a bioinformatics study that reveals that BGCs are frequently linked to genes coding for LuxR family QS-responsive transcription factors in the phylum Proteobacteria. The products of these luxR homolog-associated gene clusters may serve as a practical source of bioactive metabolites.
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Aruldass CA, Masalamany SRL, Venil CK, Ahmad WA. Antibacterial mode of action of violacein from Chromobacterium violaceum UTM5 against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:5164-5180. [PMID: 28361404 DOI: 10.1007/s11356-017-8855-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 03/17/2017] [Indexed: 06/07/2023]
Abstract
Violacein, violet pigment produced by Chromobacterium violaceum, has attracted much attention recently due to its pharmacological properties including antibacterial activity. The present study investigated possible antibacterial mode of action of violacein from C. violaceum UTM5 against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains. Violet fraction was obtained by cultivating C. violaceum UTM5 in liquid pineapple waste medium, extracted, and fractionated using ethyl acetate and vacuum liquid chromatography technique. Violacein was quantified as major compound in violet fraction using HPLC analysis. Violet fraction displayed bacteriostatic activity against S. aureus ATCC 29213 and methicillin-resistant S. aureus ATCC 43300 with minimum inhibitory concentration (MIC) of 3.9 μg/mL. Fluorescence dyes for membrane damage and scanning electron microscopic analysis confirmed the inhibitory effect by disruption on membrane integrity, morphological alternations, and rupture of the cell membranes of both strains. Transmission electron microscopic analysis showed membrane damage, mesosome formation, and leakage of intracellular constituents of both bacterial strains. Mode of action of violet fraction on the cell membrane integrity of both strains was shown by release of protein, K+, and extracellular adenosine 5'-triphosphate (ATP) with 110.5 μg/mL, 2.34 μg/mL, and 87.24 ng/μL, respectively, at 48 h of incubation. Violet fraction was toxic to human embryonic kidney (HEK293) and human fetal lung fibroblast (IMR90) cell lines with LC50 value of 0.998 ± 0.058 and 0.387 ± 0.002 μg/mL, respectively. Thus, violet fraction showed a strong antibacterial property by disrupting the membrane integrity of S. aureus and MRSA strains. This is the first report on the possible mode of antibacterial action of violet fraction from C. violaceum UTM5 on S. aureus and MRSA strains.
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Affiliation(s)
- Claira Arul Aruldass
- Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, UTM, 81310, Johor Bahru, Johor, Malaysia
| | | | | | - Wan Azlina Ahmad
- Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, UTM, 81310, Johor Bahru, Johor, Malaysia.
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Cyanide Production by Chromobacterium piscinae Shields It from Bdellovibrio bacteriovorus HD100 Predation. mBio 2017; 8:mBio.01370-17. [PMID: 29259082 PMCID: PMC5736907 DOI: 10.1128/mbio.01370-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Predation of Chromobacterium piscinae by Bdellovibrio bacteriovorus HD100 was inhibited in dilute nutrient broth (DNB) but not in HEPES. Experiments showed that the effector responsible was present in the medium, as cell-free supernatants retained the ability to inhibit predation, and that the effector was not toxic to B. bacteriovorus. Violacein, a bisindole secondary metabolite produced by C. piscinae, was not responsible. Further characterization of C. piscinae found that this species produces sufficient concentrations of cyanide (202 µM) when grown in DNB to inhibit the predatory activity of B. bacteriovorus, but that in HEPES, the cyanide concentrations were negligible (19 µM). The antagonistic role of cyanide was further confirmed, as the addition of hydroxocobalamin, which chelates cyanide, allowed predation to proceed. The activity of cyanide against B. bacteriovorus was found to be twofold, depending on the life cycle stage of this predator. For the attack-phase predatory cells, cyanide caused the cells to lose motility and tumble, while for intraperiplasmic predators, development and lysis of the prey cell were halted. These findings suggest that cyanogenesis in nature may be employed by the bacterial strains that produce this compound to prevent and reduce their predation by B. bacteriovorus. Bacterial predators actively attack, kill, and enter the periplasm of susceptible Gram-negative bacteria, where they consume the prey cell components. To date, the activity of B. bacteriovorus HD100 has been demonstrated against more than 100 human pathogens. As such, this strain and others are being considered as potential alternatives or supplements to conventional antibiotics. However, the production of secondary metabolites by prey bacteria is known to mitigate, and even abolish, predation by bacterivorous nematodes and protists. With the exception of indole, which was shown to inhibit predation, the effects of bacterial secondary metabolites on B. bacteriovorus and its activities have not been considered. Consequently, we undertook this study to better understand the mechanisms that bacterial strains employ to inhibit predation by B. bacteriovorus HD100. We report here that cyanogenic bacterial strains can inhibit predation and show that cyanide affects both attack-phase predators and those within prey, i.e., in the bdelloplast.
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Wong L, Engel J, Jin E, Holdridge B, Xu P. YaliBricks, a versatile genetic toolkit for streamlined and rapid pathway engineering in Yarrowia lipolytica. Metab Eng Commun 2017; 5:68-77. [PMID: 29188186 PMCID: PMC5699529 DOI: 10.1016/j.meteno.2017.09.001] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 09/22/2017] [Accepted: 09/25/2017] [Indexed: 11/16/2022] Open
Abstract
Effective metabolic engineering of microorganisms relies on balanced expression of both heterologous and endogenous genes to channel metabolic flux towards products of interest while achieving reasonable biomass buildup. To facilitate combinatorial pathway engineering and facile genetic operation, we engineered a set of modular cloning vectors compatible with BioBrick standards, called YaliBricks, to allow for rapid assembly of multigene pathways with customized genetic control elements (promoters, intronic sequences and terminators) in the oleaginous yeast Yarrowia lipolytica. We established a sensitive luciferase reporter and characterized a set of 12 native promoters to expand the oleaginous yeast genetic toolbox for transcriptional fine-tuning. We harnessed the intron alternative splicing mechanism and explored three unique gene configurations that allow us to encode genetic structural variations into metabolic function. We elucidated the role of how these genetic structural variations affect gene expression. To demonstrate the simplicity and effectiveness of streamlined genetic operations, we assembled the 12 kb five-gene violacein biosynthetic pathway in one week. We also expanded this set of vectors to accommodate self-cleavage ribozymes and efficiently deliver guide RNA (gRNA) for targeted genome-editing with a codon-optimized CRISPR-Cas9 nuclease. Taken together, the tools built in this study provide a standard procedure to streamline and accelerate metabolic pathway engineering and genetic circuits construction in Yarrowia lipolytica.
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Affiliation(s)
- Lynn Wong
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, United States
| | - Jake Engel
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, United States
| | - Erqing Jin
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, United States
- Department of Food Science and Engineering, Jinan University, 601 West Huangpu Road, Guangzhou 510632, China
| | - Benjamin Holdridge
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, United States
| | - Peng Xu
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, United States
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Domröse A, Weihmann R, Thies S, Jaeger KE, Drepper T, Loeschcke A. Rapid generation of recombinant Pseudomonas putida secondary metabolite producers using yTREX. Synth Syst Biotechnol 2017; 2:310-319. [PMID: 29552656 PMCID: PMC5851919 DOI: 10.1016/j.synbio.2017.11.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 10/03/2017] [Accepted: 11/03/2017] [Indexed: 11/18/2022] Open
Abstract
Microbial secondary metabolites represent a rich source of valuable compounds with a variety of applications in medicine or agriculture. Effective exploitation of this wealth of chemicals requires the functional expression of the respective biosynthetic genes in amenable heterologous hosts. We have previously established the TREX system which facilitates the transfer, integration and expression of biosynthetic gene clusters in various bacterial hosts. Here, we describe the yTREX system, a new tool adapted for one-step yeast recombinational cloning of gene clusters. We show that with yTREX, Pseudomonas putida secondary metabolite production strains can rapidly be constructed by random targeting of chromosomal promoters by Tn5 transposition. Feasibility of this approach was corroborated by prodigiosin production after yTREX cloning, transfer and expression of the respective biosynthesis genes from Serratia marcescens. Furthermore, the applicability of the system for effective pathway rerouting by gene cluster adaptation was demonstrated using the violacein biosynthesis gene cluster from Chromobacterium violaceum, producing pathway metabolites violacein, deoxyviolacein, prodeoxyviolacein, and deoxychromoviridans. Clones producing both prodigiosin and violaceins could be readily identified among clones obtained after random chromosomal integration by their strong color-phenotype. Finally, the addition of a promoter-less reporter gene enabled facile detection also of phenazine-producing clones after transfer of the respective phenazine-1-carboxylic acid biosynthesis genes from Pseudomonas aeruginosa. All compounds accumulated to substantial titers in the mg range. We thus corroborate here the suitability of P. putida for the biosynthesis of diverse natural products, and demonstrate that the yTREX system effectively enables the rapid generation of secondary metabolite producing bacteria by activation of heterologous gene clusters, applicable for natural compound discovery and combinatorial biosynthesis.
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Affiliation(s)
- Andreas Domröse
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, Jülich, Germany
| | - Robin Weihmann
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, Jülich, Germany
| | - Stephan Thies
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, Jülich, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, Jülich, Germany
- Institute of Bio- and Geosciences (IBG-1), Forschungszentrum Jülich, Jülich, Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, Jülich, Germany
| | - Anita Loeschcke
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, Jülich, Germany
- Corresponding author. Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany.Institute of Molecular Enzyme TechnologyHeinrich Heine University DüsseldorfForschungszentrum JülichJülichGermany
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Nicoletti G, Saler M, Pellegatta T, Tresoldi MM, Bonfanti V, Malovini A, Faga A, Riva F. Ex vivo regenerative effects of a spring water. Biomed Rep 2017; 7:508-514. [PMID: 29188053 PMCID: PMC5702968 DOI: 10.3892/br.2017.1002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/14/2017] [Indexed: 12/02/2022] Open
Abstract
Previous experiments by our group have indicated the regenerative effects of a spring water (Comano), which was possibly associated with the native non-pathogenic bacterial flora. The present study aimed to confirm these regenerative properties in a human ex vivo experimental model in the context of physiological wound healing. Human 6-mm punch skin biopsies harvested during plastic surgery sessions were injured in their central portion to induce skin loss and were cultured in either conventional medium (controls) or medium powder reconstituted with filtered Comano spring water (treated samples). At 24, 48 and 72 h the specimens were observed following staining with hematoxylin and eosin, Picrosirius Red, orcein and anti-proliferating cell nuclear antigen. Compared with the controls, the treated samples exhibited reduced overall cell infiltration, evidence of fibroblasts, stimulation of cell proliferation and collagen and elastic fiber regeneration. In the spring water, in addition to 12 resident non-pathogenic bacterial strains exhibiting favorable metabolic activities, more unknown non-pathogenic species are being identified by genomic analysis. In the present study, the efficacy of this ‘germ-free’, filtered spring water in wound regeneration was indicated. Thus, the Comano spring water microbiota should be acknowledged for its regenerative properties.
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Affiliation(s)
- Giovanni Nicoletti
- Plastic and Reconstructive Surgery, Department of Clinical-Surgical Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy.,Advanced Technologies for Regenerative Medicine and Inductive Surgery Research Center, University of Pavia, 27100 Pavia, Italy.,Plastic and Reconstructive Surgery Unit, Salvatore Maugeri Research and Care Institute, 27100 Pavia, Italy
| | - Marco Saler
- Plastic and Reconstructive Surgery, Department of Clinical-Surgical Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy
| | - Tommaso Pellegatta
- Plastic and Reconstructive Surgery, Department of Clinical-Surgical Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy
| | - Marco Mario Tresoldi
- Plastic and Reconstructive Surgery, Department of Clinical-Surgical Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy.,Plastic and Reconstructive Surgery Unit, Salvatore Maugeri Research and Care Institute, 27100 Pavia, Italy
| | - Viola Bonfanti
- Plastic and Reconstructive Surgery, Department of Clinical-Surgical Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy
| | - Alberto Malovini
- Laboratory of Informatics and Systems Engineering for Clinical Research, Istituti Clinici Scientifici Maugeri, 27100 Pavia, Italy
| | - Angela Faga
- Plastic and Reconstructive Surgery, Department of Clinical-Surgical Diagnostic and Pediatric Sciences, University of Pavia, 27100 Pavia, Italy.,Advanced Technologies for Regenerative Medicine and Inductive Surgery Research Center, University of Pavia, 27100 Pavia, Italy.,Plastic and Reconstructive Surgery Unit, Salvatore Maugeri Research and Care Institute, 27100 Pavia, Italy
| | - Federica Riva
- Advanced Technologies for Regenerative Medicine and Inductive Surgery Research Center, University of Pavia, 27100 Pavia, Italy.,Department of Public Health, Experimental and Forensic Medicine, Histology and Embryology Unit, University of Pavia, 27100 Pavia, Italy
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Antimicrobial Effects of Violacein against Planktonic Cells and Biofilms of Staphylococcus aureus. Molecules 2017; 22:molecules22101534. [PMID: 28946655 PMCID: PMC6151432 DOI: 10.3390/molecules22101534] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 09/07/2017] [Accepted: 09/09/2017] [Indexed: 11/16/2022] Open
Abstract
Violacein is an indole compound, produced by Chromobacterium violaceum, a bacteria present in tropical and subtropical areas. Among its numerous biological activities, its antimicrobial potential stands out. This study aims to determine the antimicrobial activity of VIO on S. aureus in planktonic culture and biofilms. VIO showed excellent antimicrobial activity in inhibiting and killing S. aureus in planktonic cultures and biofilm formation. The minimum bactericidal concentration (5 μg/mL) of VIO caused the death of S. aureus after 3-4 h of exposure and the minimum inhibitory concentration (1.25 μg/mL) of VIO inhibited bacterial growth within the first 8 h of contact. Biofilm formation was also strongly inhibited by VIO (1.25 μg/mL), in contrast to the higher resistance verified for S. aureus in mature biofilm (40 μg/mL). The high bacterial metabolic activity favored VIO activity; however, the good activity observed during phases of reduced metabolism indicates that VIO action involves more than one mechanism. Thus, VIO is a promising molecule for the development of an antimicrobial drug for the eradication of S. aureus infections.
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Timmermans ML, Paudel YP, Ross AC. Investigating the Biosynthesis of Natural Products from Marine Proteobacteria: A Survey of Molecules and Strategies. Mar Drugs 2017; 15:E235. [PMID: 28762997 PMCID: PMC5577590 DOI: 10.3390/md15080235] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/21/2017] [Accepted: 07/24/2017] [Indexed: 02/07/2023] Open
Abstract
The phylum proteobacteria contains a wide array of Gram-negative marine bacteria. With recent advances in genomic sequencing, genome analysis, and analytical chemistry techniques, a whole host of information is being revealed about the primary and secondary metabolism of marine proteobacteria. This has led to the discovery of a growing number of medically relevant natural products, including novel leads for the treatment of multidrug-resistant Staphylococcus aureus (MRSA) and cancer. Of equal interest, marine proteobacteria produce natural products whose structure and biosynthetic mechanisms differ from those of their terrestrial and actinobacterial counterparts. Notable features of secondary metabolites produced by marine proteobacteria include halogenation, sulfur-containing heterocycles, non-ribosomal peptides, and polyketides with unusual biosynthetic logic. As advances are made in the technology associated with functional genomics, such as computational sequence analysis, targeted DNA manipulation, and heterologous expression, it has become easier to probe the mechanisms for natural product biosynthesis. This review will focus on genomics driven approaches to understanding the biosynthetic mechanisms for natural products produced by marine proteobacteria.
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Affiliation(s)
| | - Yagya P Paudel
- Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada.
| | - Avena C Ross
- Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada.
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Wu YH, Cheng H, Xu L, Jin XB, Wang CS, Xu XW. Physiological and genomic features of a novel violacein-producing bacterium isolated from surface seawater. PLoS One 2017. [PMID: 28640915 PMCID: PMC5481030 DOI: 10.1371/journal.pone.0179997] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Strains JW1T and JW3, isolated from surface seawater of the Arabian Sea, were subjected to polyphasic taxonomic analysis. Cells of both strains were Gram-stain-negative, aerobic, and rod-shaped. They formed violet pigment and produced violacein. On the basis of 16S rRNA gene sequence analysis, strains JW1T and JW3 showed high 16S rRNA gene sequence similarity with Pseudoalteromonas byunsanensis JCM12483T (98.2%), P. shioyasakiensis SE3T (97.8%), P. arabiensis JCM 17292T (97.3%), and P. gelatinilytica NH153T (97.1%). The 16S rRNA gene sequence similarity between JW1T and JW3 was 100%. Phylogenetic analyses revealed that both strains fell within the cluster of the genus Pseudoalteromonas and represented an independent lineage. The average nucleotide identity and in silico DNA-DNA hybridization values between JW1T and type strains of the closely related Pseudoalteromonas species were 70.9–83.3% and 20.0–26.4%, respectively. The sole respiratory quinone in both strains is ubiquinone 8 (Q-8). The principal fatty acids are summed feature 3 (C16:1ω7c and/or iso-C15:0 2OH), C18:1ω7c, and C16:0. The major polar lipids are phosphatidylethanolamine, phosphatidylglycerol, one unidentified glycolipid, one unidentified aminolipid, and one unidentified phospholipid. The DNA G+C content was 43.3 mol%. Differential phylogenetic distinctiveness, chemotaxonomic differences, and phenotypic properties indicated that strains JW1T and JW3 could be differentiated from the Pseudoalteromonas species with validly published names. Therefore, it is proposed that strains JW1T and JW3 represent a novel species of the genus Pseudoalteromonas, for which the name Pseudoalteromonas amylolytica sp. nov. (type strain, JW1T = CGMCC 1.15681T = KCTC 52406T = MCCC 1K02162T) is proposed.
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Affiliation(s)
- Yue-Hong Wu
- Key Laboratory of Marine Ecosystem and Biogeochemistry, Second Institute of Oceanography, State Oceanic Administration, Hangzhou, P. R. China
| | - Hong Cheng
- Key Laboratory of Marine Ecosystem and Biogeochemistry, Second Institute of Oceanography, State Oceanic Administration, Hangzhou, P. R. China
| | - Lin Xu
- Key Laboratory of Marine Ecosystem and Biogeochemistry, Second Institute of Oceanography, State Oceanic Administration, Hangzhou, P. R. China
| | - Xiong-Bin Jin
- Key Laboratory of Marine Ecosystem and Biogeochemistry, Second Institute of Oceanography, State Oceanic Administration, Hangzhou, P. R. China
| | - Chun-Sheng Wang
- Key Laboratory of Marine Ecosystem and Biogeochemistry, Second Institute of Oceanography, State Oceanic Administration, Hangzhou, P. R. China
| | - Xue-Wei Xu
- Key Laboratory of Marine Ecosystem and Biogeochemistry, Second Institute of Oceanography, State Oceanic Administration, Hangzhou, P. R. China
- * E-mail:
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Wang Y, Heermann R, Jung K. CipA and CipB as Scaffolds To Organize Proteins into Crystalline Inclusions. ACS Synth Biol 2017; 6:826-836. [PMID: 28186716 DOI: 10.1021/acssynbio.6b00323] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Natural and synthetic scaffolds support enzyme organization in complexes, and they regulate their function and activity. Here we report that CipA and CipB, two small proteins that form protein crystalline inclusions (PCIs) in the cytoplasm of Photorhabdus luminescens, can be utilized as scaffolds to efficiently incorporate exogenous proteins into PCIs. We demonstrate that Cip-tagged GFP is assembled into fluorescent PCIs in P. luminescens and that in Escherichia coli Cip scaffolds can organize GFP or/and LacZ into bioactive PCIs, which could easily be isolated for in vitro catalysis. To explore its in vivo application further, we used CipA to bring together multiple enzymes (Vio enzymes) of the violacein biosynthetic pathway. The resulting complexes were found to produce significantly higher yields of violacein and fewer byproducts than did Vio enzymes in solution. Hence, Cip scaffolds should be widely applicable to biotechnological processes both in vitro and in vivo.
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Affiliation(s)
- Yang Wang
- Munich Center for Integrated Protein
Science (CIPSM) at the Department of Microbiology, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany
| | - Ralf Heermann
- Munich Center for Integrated Protein
Science (CIPSM) at the Department of Microbiology, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany
| | - Kirsten Jung
- Munich Center for Integrated Protein
Science (CIPSM) at the Department of Microbiology, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany
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Banerjee D, Parmar D, Bhattacharya N, Ghanate AD, Panchagnula V, Raghunathan A. A scalable metabolite supplementation strategy against antibiotic resistant pathogen Chromobacterium violaceum induced by NAD +/NADH + imbalance. BMC SYSTEMS BIOLOGY 2017; 11:51. [PMID: 28446174 PMCID: PMC5405553 DOI: 10.1186/s12918-017-0427-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/21/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND The leading edge of the global problem of antibiotic resistance necessitates novel therapeutic strategies. This study develops a novel systems biology driven approach for killing antibiotic resistant pathogens using benign metabolites. RESULTS Controlled laboratory evolutions established chloramphenicol and streptomycin resistant pathogens of Chromobacterium. These resistant pathogens showed higher growth rates and required higher lethal doses of antibiotic. Growth and viability testing identified malate, maleate, succinate, pyruvate and oxoadipate as resensitising agents for antibiotic therapy. Resistant genes were catalogued through whole genome sequencing. Intracellular metabolomic profiling identified violacein as a potential biomarker for resistance. The temporal variance of metabolites captured the linearized dynamics around the steady state and correlated to growth rate. A constraints-based flux balance model of the core metabolism was used to predict the metabolic basis of antibiotic susceptibility and resistance. CONCLUSIONS The model predicts electron imbalance and skewed NAD/NADH ratios as a result of antibiotics - chloramphenicol and streptomycin. The resistant pathogen rewired its metabolic networks to compensate for disruption of redox homeostasis. We foresee the utility of such scalable workflows in identifying metabolites for clinical isolates as inevitable solutions to mitigate antibiotic resistance.
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Affiliation(s)
- Deepanwita Banerjee
- Chemical Engineering Division, CSIR-National Chemical Laboratory, Pune, India
| | | | | | - Avinash D. Ghanate
- Chemical Engineering Division, CSIR-National Chemical Laboratory, Pune, India
| | | | - Anu Raghunathan
- Chemical Engineering Division, CSIR-National Chemical Laboratory, Pune, India
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Dang HT, Komatsu S, Masuda H, Enomoto K. Characterization of LuxI and LuxR Protein Homologs of N-Acylhomoserine Lactone-Dependent Quorum Sensing System in Pseudoalteromonas sp. 520P1. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2017; 19:1-10. [PMID: 28083715 DOI: 10.1007/s10126-016-9726-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 12/08/2016] [Indexed: 06/06/2023]
Abstract
Pseudoalteromonas sp. 520P1 (hereafter referred to as strain 520P1) produces N-acylhomoserine lactones (AHLs), which serve as signaling molecules in Gram-negative bacterial quorum sensing. In a previous genomic analysis of the 5.25-Mb genome of strain 520P1, we detected the presence of at least one homolog of the AHL synthase gene (luxI) and five homologs of the transcriptional regulator protein gene (luxR). The LuxI homolog of strain 520P1 (PalI) contained the conserved amino acid motifs shared by all the LuxI family proteins of the different species examined here. The palI gene expressed in Escherichia coli produced two types of AHLs. In the thin-layer chromatography analysis, these AHLs showed identical mobility to the AHLs produced by strain 520P1. The five LuxR homologs of strain 520P1 (PalR1-PalR5) shared only 17-34% amino acid sequence identity, although higher identities were observed in the C-terminal DNA-binding domain. Among the five PalRs, only PalR5 displayed close homology with LuxR family proteins from other Pseudoalteromonas strains. Notably, the palR3 and palI genes were located close together and only 1021 bases apart in the genome. No cognate luxI homolog associated with the four other palR genes was detected. These characteristics of PalI and the PalRs suggest that AHL autoinducers generated by the PalI enzyme might regulate cellular metabolism in cooperation with five transcriptional regulator PalRs, each of which is presumed to play a distinctive role in bacterial signaling.
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Affiliation(s)
- Hoang Tran Dang
- School of Environmental Science and Engineering, Kochi University of Technology, 185 Miyanokuchi, Tosayamada, Kami, Kochi, 782-8502, Japan
| | - Shinya Komatsu
- School of Environmental Science and Engineering, Kochi University of Technology, 185 Miyanokuchi, Tosayamada, Kami, Kochi, 782-8502, Japan
| | - Hideyuki Masuda
- School of Environmental Science and Engineering, Kochi University of Technology, 185 Miyanokuchi, Tosayamada, Kami, Kochi, 782-8502, Japan
| | - Keiichi Enomoto
- School of Environmental Science and Engineering, Kochi University of Technology, 185 Miyanokuchi, Tosayamada, Kami, Kochi, 782-8502, Japan.
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Arif S, Batool A, Khalid N, Ahmed I, Janjua HA. Comparative analysis of stability and biological activities of violacein and starch capped silver nanoparticles. RSC Adv 2017; 7:4468-4478. [DOI: 10.1039/c6ra25806a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024] Open
Abstract
This study highlights the synthesis of starch and violacein capped AgNPs through reducing agents. The violacein capped AgNPs are more stable than starch capped AgNPs and have more potent antimicrobial activities in comparison to starch capped AgNPs.
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Affiliation(s)
- Sania Arif
- Department of Industrial Biotechnology
- Atta-ur-Rahman School of Applied Biosciences
- National University of Science and Technology (NUST)
- Islamabad
- Pakistan
| | - Aamina Batool
- School of Chemical and Material Engineering
- National University of Science and Technology (NUST)
- Islamabad
- Pakistan
| | - Nauman Khalid
- School of Food and Agricultural Sciences
- University of Management and Technology
- Lahore 54000
- Pakistan
- Centre for Chemistry and Biotechnology
| | - Iftikhar Ahmed
- Institute of Microbial Culture Collection of Pakistan (IMCCP)
- National Agricultural Research Centre (NARC)
- Islamabad-45500
- Pakistan
| | - Hussnain Ahmed Janjua
- Department of Industrial Biotechnology
- Atta-ur-Rahman School of Applied Biosciences
- National University of Science and Technology (NUST)
- Islamabad
- Pakistan
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