1
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Roca A, Cabeo M, Enguidanos C, Martínez-Checa F, Sampedro I, Llamas I. Potential of the quorum-quenching and plant-growth promoting halotolerant Bacillus toyonensis AA1EC1 as biocontrol agent. Microb Biotechnol 2024; 17:e14420. [PMID: 38532596 DOI: 10.1111/1751-7915.14420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 03/28/2024] Open
Abstract
The use of fertilizers and pesticides to control plant diseases is widespread in intensive farming causing adverse effects together with the development of antimicrobial resistance pathogens. As the virulence of many Gram-negative phytopathogens is controlled by N-acyl-homoserine lactones (AHLs), the enzymatic disruption of this type of quorum-sensing (QS) signal molecules, mechanism known as quorum quenching (QQ), has been proposed as a promising alternative antivirulence therapy. In this study, a novel strain of Bacillus toyonensis isolated from the halophyte plant Arthrocaulon sp. exhibited numerous traits associated with plant growth promotion (PGP) and degraded a broad range of AHLs. Three lactonases and an acylase enzymes were identified in the bacterial genome and verified in vitro. The AHL-degrading activity of strain AA1EC1 significantly attenuated the virulence of relevant phytopathogens causing reduction of soft rot symptoms on potato and carrots. In vivo assays showed that strain AA1EC1 significantly increased plant length, stem width, root and aerial dry weights and total weight of tomato and protected plants against Pseudomonas syringae pv. tomato. To our knowledge, this is the first report to demonstrate PGP and QQ activities in the species B. toyonensis that make this strain as a promising phytostimulant and biocontrol agent.
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Affiliation(s)
- Amalia Roca
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
| | - Mónica Cabeo
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Carlos Enguidanos
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Fernando Martínez-Checa
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
| | - Inmaculada Sampedro
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
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2
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Sánchez P, Castro-Cegrí A, Sierra S, Garrido D, Llamas I, Sampedro I, Palma F. The synergy of halotolerant PGPB and mauran mitigates salt stress in tomato (Solanum lycopersicum) via osmoprotectants accumulation. Physiol Plant 2023; 175:e14111. [PMID: 38148230 DOI: 10.1111/ppl.14111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 12/28/2023]
Abstract
Salinity stress is one of the major abiotic factors limiting sustainable agriculture. Halotolerant plant growth-promoting bacteria (PGPB) increased salt stress tolerance in plants, but the mechanisms underlying the tolerance are poorly understood. This study investigated the PGP activity of four halotolerant bacteria under salinity stress and the tomato salt-tolerance mechanisms induced by the synergy of these bacteria with the exopolysaccharide (EPS) mauran. All PGPB tested in this study were able to offer a significant improvement of tomato plant biomass under salinity stress; Peribacillus castrilensis N3 being the most efficient one. Tomato plants treated with N3 and the EPS mauran showed greater tolerance to NaCl than the treatment in the absence of EPS and PGPB. The synergy of N3 with mauran confers salt stress tolerance in tomato plants by increasing sodium transporter genes' expression and osmoprotectant content, including soluble sugars, polyols, proline, GABA, phenols and the polyamine putrescine. These osmolytes together with the induction of sodium transporter genes increase the osmotic adjustment capacity to resist water loss and maintain ionic homeostasis. These findings suggest that the synergy of the halotolerant bacterium N3 and the EPS mauran could enhance tomato plant growth by mitigating salt stress and could have great potential as an inductor of salinity tolerance in the agriculture sector.
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Affiliation(s)
- Patricia Sánchez
- Department of Microbiology, Pharmacy Faculty, University of Granada, Spain
| | | | - Sandra Sierra
- Department of Plant Physiology, Science Faculty, University of Granada, Granada, Spain
| | - Dolores Garrido
- Department of Plant Physiology, Science Faculty, University of Granada, Granada, Spain
| | - Inmaculada Llamas
- Department of Microbiology, Pharmacy Faculty, University of Granada, Spain
- Biomedical Research Center (CIBM), Biotechnology Institute, Granada, Spain
| | - Inmaculada Sampedro
- Department of Microbiology, Pharmacy Faculty, University of Granada, Spain
- Biomedical Research Center (CIBM), Biotechnology Institute, Granada, Spain
| | - Francisco Palma
- Department of Plant Physiology, Science Faculty, University of Granada, Granada, Spain
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3
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Toral L, Rodríguez M, Martínez-Checa F, Montaño A, Cortés-Delgado A, Smolinska A, Llamas I, Sampedro I. Corrigendum: Identification of volatile organic compounds in extremophilic bacteria and their effective use in biocontrol of postharvest fungal phytopathogens. Front Microbiol 2023; 14:1267324. [PMID: 37637106 PMCID: PMC10450139 DOI: 10.3389/fmicb.2023.1267324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 07/28/2023] [Indexed: 08/29/2023] Open
Abstract
[This corrects the article DOI: 10.3389/fmicb.2021.773092.].
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Affiliation(s)
- Laura Toral
- Xtrem Biotech S.L., European Business Innovation Center, Avenida de la Innovación, Granada, Spain
| | - Miguel Rodríguez
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, Granada, Spain
- Biomedical Research Center (CIBM), Avenida del Conocimiento s/n, Granada, Spain
| | - Fernando Martínez-Checa
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, Granada, Spain
- Biomedical Research Center (CIBM), Avenida del Conocimiento s/n, Granada, Spain
| | - Alfredo Montaño
- Department of Food Biotechnology, Instituto de la Grasa, Sevilla, Spain
| | | | - Agnieszka Smolinska
- Department of Pharmacology and Toxicology, Maastricht University, Maastricht, Netherlands
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, Granada, Spain
- Biomedical Research Center (CIBM), Avenida del Conocimiento s/n, Granada, Spain
| | - Inmaculada Sampedro
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, Granada, Spain
- Biomedical Research Center (CIBM), Avenida del Conocimiento s/n, Granada, Spain
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4
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Rodríguez M, Reina JC, Sampedro I, Llamas I, Martínez-Checa F. Peribacillus castrilensis sp. nov.: A Plant-Growth-Promoting and Biocontrol Species Isolated From a River Otter in Castril, Granada, Southern Spain. Front Plant Sci 2022; 13:896728. [PMID: 35812926 PMCID: PMC9262404 DOI: 10.3389/fpls.2022.896728] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/23/2022] [Indexed: 06/15/2023]
Abstract
A strictly aerobic, chemoheterotrophic, endospore-forming, Gram-positive, rod-shaped bacterial strain N3T was isolated from the feces of a river otter in Castril (Granada, southern Spain). It is halotolerant, motile, and catalase-, oxidase-, ACC deaminase-, and C4- and C8-lipase-positive. It promotes tomato plant growth and can reduce virulence in Erwinia amylovora CECT 222T and Dickeya solani LMG 25993T through interference in their quorum-sensing systems, although other antagonistic mechanisms could also occur. A phylogenetic analysis of the 16S rRNA gene sequence as well as the phenotypic and phylogenomic analyses indicated that the strain N3T is a novel species of the genus Peribacillus, with the highest 16S rRNA sequence similar to that of Bacillus frigoritolerans DSM 8801T (99.93%) and Peribacillus simplex DSM 1321T (99.80%). Genomic digital DNA-DNA hybridization (dDDH) between the strain N3T and Bacillus frigoritolerans DSM 8801T and Peribacillus simplex was 12.8 and 69.1%, respectively, and the average nucleotide identity (ANIb) of strain N3T and Bacillus frigoritolerans DSM 8801T and Peribacillus simplex was 67.84 and 93.21%, respectively. The genomic G + C content was 40.3 mol%. Its main cellular fatty acids were anteiso-C15:0 and iso-C15:0. Using 16S rRNA phylogenetic and in silico phylogenomic analyses, together with the chemotaxonomic and phenotypic data, we demonstrated that the type strain N3T (=CECT 30509T = LMG 32505T) is a novel species of the genus Peribacillus and the name Peribacillus castrilensis sp. nov. is proposed.
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Affiliation(s)
- Miguel Rodríguez
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - José Carlos Reina
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Inmaculada Sampedro
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Biomedical Research Centre (CIBM), Institute of Biotechnology, University of Granada, Granada, Spain
| | - Fernando Martínez-Checa
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Biomedical Research Centre (CIBM), Institute of Biotechnology, University of Granada, Granada, Spain
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5
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Reina JC, Pérez P, Llamas I. Quorum Quenching Strains Isolated from the Microbiota of Sea Anemones and Holothurians Attenuate Vibriocorallilyticus Virulence Factors and Reduce Mortality in Artemiasalina. Microorganisms 2022; 10:microorganisms10030631. [PMID: 35336206 PMCID: PMC8950658 DOI: 10.3390/microorganisms10030631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/08/2022] [Accepted: 03/14/2022] [Indexed: 01/19/2023] Open
Abstract
Interference with quorum-sensing (QS) intercellular communication systems by the enzymatic disruption of N-acylhomoserine lactones (AHLs) in Gram-negative bacteria has become a promising strategy to fight bacterial infections. In this study, seven strains previously isolated from marine invertebrates and selected for their ability to degrade C6 and C10-HSL, were identified as Acinetobacter junii, Ruegeria atlantica, Microbulbifer echini, Reinheimera aquimaris, and Pseudomonas sihuiensis. AHL-degrading activity against a wide range of synthetic AHLs were identified by using an agar well diffusion assay and Agrobacterium tumefaciens NTL4 and Chromobacterium violaceum CV026 and VIR07 as biosensors. High-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis indicated that this activity was not due to an AHL lactonase. All the strains degraded Vibrio coralliilyticus AHLs in coculture experiments, while some strains reduced or abolished the production of virulence factors. In vivo assays showed that strains M3-111 and M3-127 reduced this pathogen’s virulence and increased the survival rate of Artemia salina up to 3-fold, indicating its potential use for biotechnological purposes. To our knowledge, this is the first study to describe AHL-degrading activities in some of these marine species. These findings highlight that the microbiota associated with marine invertebrates constitute an important underexplored source of biological valuable compounds.
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Affiliation(s)
- José Carlos Reina
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain; (J.C.R.); (P.P.)
| | - Pedro Pérez
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain; (J.C.R.); (P.P.)
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain; (J.C.R.); (P.P.)
- Biomedical Research Center (CIBM), Institute of Biotechnology, University of Granada, 18100 Granada, Spain
- Correspondence:
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6
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Toral L, Rodríguez M, Martínez-Checa F, Montaño A, Cortés-Delgado A, Smolinska A, Llamas I, Sampedro I. Identification of Volatile Organic Compounds in Extremophilic Bacteria and Their Effective Use in Biocontrol of Postharvest Fungal Phytopathogens. Front Microbiol 2021; 12:773092. [PMID: 34867910 PMCID: PMC8633403 DOI: 10.3389/fmicb.2021.773092] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/11/2021] [Indexed: 11/17/2022] Open
Abstract
Phytopathogenic fungal growth in postharvest fruits and vegetables is responsible for 20-25% of production losses. Volatile organic compounds (VOCs) have been gaining importance in the food industry as a safe and ecofriendly alternative to pesticides for combating these phytopathogenic fungi. In this study, we analysed the ability of some VOCs produced by strains of the genera Bacillus, Peribacillus, Pseudomonas, Psychrobacillus and Staphylococcus to inhibit the growth of Alternaria alternata, Botrytis cinerea, Fusarium oxysporum, Fusarium solani, Monilinia fructicola, Monilinia laxa and Sclerotinia sclerotiorum, in vitro and in vivo. We analysed bacterial VOCs by using GC/MS and 87 volatile compounds were identified, in particular acetoin, acetic acid, 2,3-butanediol, isopentanol, dimethyl disulphide and isopentyl isobutanoate. In vitro growth inhibition assays and in vivo experiments using cherry fruits showed that the best producers of VOCs, Bacillus atrophaeus L193, Bacillus velezensis XT1 and Psychrobacillus vulpis Z8, exhibited the highest antifungal activity against B. cinerea, M. fructicola and M. laxa, which highlights the potential of these strains to control postharvest diseases. Transmission electron microscopy micrographs of bacterial VOC-treated fungi clearly showed antifungal activity which led to an intense degeneration of cellular components of mycelium and cell death.
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Affiliation(s)
- Laura Toral
- Xtrem Biotech S.L., European Business Innovation Center, Avenida de la Innovación, Granada, Spain
| | - Miguel Rodríguez
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, Granada, Spain
- Biomedical Research Center (CIBM), Avenida del Conocimiento s/n, Granada, Spain
| | - Fernando Martínez-Checa
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, Granada, Spain
- Biomedical Research Center (CIBM), Avenida del Conocimiento s/n, Granada, Spain
| | - Alfredo Montaño
- Department of Food Biotechnology, Instituto de la Grasa, Sevilla, Spain
| | | | - Agnieszka Smolinska
- Department of Pharmacology and Toxicology, Maastricht University, Maastricht, Netherlands
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, Granada, Spain
- Biomedical Research Center (CIBM), Avenida del Conocimiento s/n, Granada, Spain
| | - Inmaculada Sampedro
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, Granada, Spain
- Biomedical Research Center (CIBM), Avenida del Conocimiento s/n, Granada, Spain
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7
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Castro DJ, Gomez-Altuve A, Reina JC, Rodríguez M, Sampedro I, Llamas I, Martínez-Checa F. Roseovarius bejariae sp. nov., a moderately halophilic bacterium isolated from a hypersaline steep-sided river bed. Int J Syst Evol Microbiol 2020; 70:3194-3201. [DOI: 10.1099/ijsem.0.004154] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An aerobic, Gram-stain-negative ovoid, designated as strain A21T, was isolated using the dilution-to-extinction method from a soil sample taken from Rambla Salada, an athalassohaline habitat located in Murcia (south-eastern Spain). Strain A21T is non-motile, has a respiratory metabolism and grows at NaCl concentrations within the range 0.5–15 % (w/v) [optimum, 5 % (w/v)], at 5–35 °C (optimum, 28 °C) and at pH 6–8 (optimum, pH 7.0). This strain is positive for catalase activity, oxidase activity and nitrate reduction. The 16S rRNA gene sequence indicates that it belongs to the genus
Roseovarius
in the class
Alphaproteobacteria
. The most closely related species are Roseovarius pacificus and Roseovarius halotolerans to which the strain A21T shows 16S rRNA gene sequence similarity values of 98.06 and 97.7 %, respectively. The average nucleotide identity in blast and digital DNA–DNA hybridization values between strain A21T and
R. pacificus
LMG 24575T are 76.8 and 21 %, respectively. The DNA G+C content based on the genome is 61.28 mol%. The major fatty acids (>5 % of the total fatty acids) of strain A21T are C18 : 1 ω7c/C18 : 1 ω6c and C16 : 0. The only detected isoprenoid quinone in strain A21T is ubiquinone 10 (Q-10). The polar lipid profile contains phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and three unidentified polar lipids. Based on the phylogenetic, genotypic, phenotypic and chemotaxonomic data, the strain represents a novel species of the genus
Roseovarius
, for which the name Roseovarius bejariae sp. nov. is proposed. Strain A21T (=CECT 9817T=LMG 31311T) is the type strain.
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Affiliation(s)
- David J. Castro
- Xtrem Biotech S.L., European Business Innovation Center, Avenida de la Innovación, 1, 18016, Armilla, Granada, Spain
- Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100, Armilla, Granada, Spain
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain
| | - Andreina Gomez-Altuve
- Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100, Armilla, Granada, Spain
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain
| | - José Carlos Reina
- Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100, Armilla, Granada, Spain
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain
| | - Miguel Rodríguez
- Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100, Armilla, Granada, Spain
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain
| | - Inmaculada Sampedro
- Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100, Armilla, Granada, Spain
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain
| | - Inmaculada Llamas
- Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100, Armilla, Granada, Spain
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain
| | - Fernando Martínez-Checa
- Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100, Armilla, Granada, Spain
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain
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8
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Sampedro I, Pérez-Mendoza D, Toral L, Palacios E, Arriagada C, Llamas I. Effects of Halophyte Root Exudates and Their Components on Chemotaxis, Biofilm Formation and Colonization of the Halophilic Bacterium Halomonas Anticariensis FP35 T. Microorganisms 2020; 8:E575. [PMID: 32316222 PMCID: PMC7232322 DOI: 10.3390/microorganisms8040575] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 12/25/2022] Open
Abstract
Increase in soil salinity poses an enormous problem for agriculture and highlights the need for sustainable crop production solutions. Plant growth-promoting bacteria can be used to boost the growth of halophytes in saline soils. Salicornia is considered to be a promising salt-accumulating halophyte for capturing large amounts of carbon from the atmosphere. In addition, colonization and chemotaxis could play an important role in Salicornia-microbe interactions. In this study, the role of chemotaxis in the colonization of the halophilic siredophore-producing bacteria, Halomonas anticariensis FP35T, on Salicornia hispanica plants was investigated. The chemotactic response of FP35T to Salicornia root exudates showed optimum dependence at a salt concentration of 5 % NaCl (w/v). Oleanolic acid, the predominant compound in the exudates detected by HPLC and identified by UPLC-HRMS Q-TOF, acts as a chemoattractant. In vitro experiments demonstrated the enhanced positive effects of wild-type H. anticariensis strain FP35T on root length, shoot length, germination and the vigour index of S. hispanica. Furthermore, these positive effects partially depend on an active chemotaxis system, as the chemotaxis mutant H. anticariensis FP35 ΔcheA showed reduced plant growth promotion for all the parameters tested. Overall, our results suggest that chemotaxis responses to root exudates play an important role in interactions between Salicornia and halophilic bacteria, enhance their colonization and boost plant growth promotion. Preliminary results also indicate that root exudates have a positive impact on H. anticariensis FP35T biofilm formation under saline conditions, an effect which totally depends on the presence of the cheA gene.
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Affiliation(s)
- Inmaculada Sampedro
- Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain; (D.P.-M.); (E.P.); (I.L.)
- Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100 Armilla, Granada, Spain
| | - Daniel Pérez-Mendoza
- Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain; (D.P.-M.); (E.P.); (I.L.)
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín, Spanish National Research Council (CSIC), Profesor Albareda 1, 18008 Granada, Spain
| | - Laura Toral
- Xtrem Biotech S.L., European Business Innovation Center, Avenida de la Innovación, 1, 18016 Armilla, Granada, Spain;
| | - Esther Palacios
- Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain; (D.P.-M.); (E.P.); (I.L.)
- Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100 Armilla, Granada, Spain
| | - César Arriagada
- Department of Forestry Science, Bioremediation Laboratory, Faculty of Agricultural and Forestry Science, University of La Frontera, 01145 Temuco, Chile;
| | - Inmaculada Llamas
- Department of Microbiology, Pharmacy Faculty, Campus de Cartuja s/n, 18071 Granada, Spain; (D.P.-M.); (E.P.); (I.L.)
- Biomedical Research Center (CIBM), Biotechnology Institute, Avda del Conocimiento s/n, 18100 Armilla, Granada, Spain
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9
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Rodríguez M, Torres M, Blanco L, Béjar V, Sampedro I, Llamas I. Plant growth-promoting activity and quorum quenching-mediated biocontrol of bacterial phytopathogens by Pseudomonas segetis strain P6. Sci Rep 2020; 10:4121. [PMID: 32139754 PMCID: PMC7058018 DOI: 10.1038/s41598-020-61084-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 02/18/2020] [Indexed: 01/18/2023] Open
Abstract
Given the major threat of phytopathogenic bacteria to food production and ecosystem stability worldwide, novel alternatives to conventional chemicals-based agricultural practices are needed to combat these bacteria. The objective of this study is to evaluate the ability of Pseudomonas segetis strain P6, which was isolated from the Salicornia europaea rhizosphere, to act as a potential biocontrol agent given its plant growth-promoting (PGP) and quorum quenching (QQ) activities. Seed biopriming and in vivo assays of tomato plants inoculated with strain P6 resulted in an increase in seedling height and weight. We detected QQ activity, involving enzymatic degradation of signal molecules in quorum sensing communication systems, against a broad range of N-acylhomoserine lactones (AHLs). HPLC-MRM data and phylogenetic analysis indicated that the QQ enzyme was an acylase. The QQ activity of strain P6 reduced soft rot symptoms caused by Dickeya solani, Pectobacterium atrosepticum and P. carotovorum on potato and carrot. In vivo assays showed that the PGP and QQ activities of strain P6 protect tomato plants against Pseudomonas syringae pv. tomato, indicating that strain P6 could have biotechnological applications. To our knowledge, this is the first report to show PGP and QQ activities in an indigenous Pseudomonas strain from Salicornia plants.
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Affiliation(s)
- Miguel Rodríguez
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Marta Torres
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain.,Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain.,Institute for Integrative Biology of the Cell (I2BC), CEA/CNRS/University Paris-Sud, University Paris-Saclay, Gif-sur-Yvette, France
| | - Lydia Blanco
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Victoria Béjar
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain.,Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
| | - Inmaculada Sampedro
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain.
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain. .,Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain.
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10
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Rodríguez M, Reina JC, Béjar V, Llamas I. Psychrobacillus vulpis sp. nov., a new species isolated from faeces of a red fox in Spain. Int J Syst Evol Microbiol 2019; 70:882-888. [PMID: 31833832 DOI: 10.1099/ijsem.0.003840] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A facultative anaerobic, chemoheterotrophic, endospore-forming, Gram-stain-positive rod, designated as strain Z8T, was isolated from red fox (Vulpes vulpes) faeces sampled at Tablas de Daimiel National Park, Ciudad Real, Spain. Strain Z8T grew at 0-37 °C (optimum, 28 °C), in the presence of 0-5.5 % (w/v) NaCl (2.5 %, w/v) and at pH 6-10 (pH 7). The strain was motile and positive for catalase, oxidase, H2S and siderophore production, acid and alkaline phosphatases, and N-acetylglucosamine, adipic acid and malate assimilation. It hydrolysed starch, DNA, l-tyrosine, Tween 20, Tween 80 and lecithovitellin. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain Z8T is a member of the genus Psychrobacillus, showing high sequence similarity to Psychrobacillus lasiicapitis NEAU-3TGS17T (99.2 %) and Psychrobacillus soli NHI-2TT (99.1 %), and around 98 % to other known species of the genus Psychrobacillus. Digital DNA-DNA hybridization and average nucleotide identity values were lower than 24 and 79 %, respectively, with the most related species. In silico G+C content was 35.9 mol%. The major cellular fatty acids of strain Z8T were iso-C14 : 0, iso-C15 : 0 and anteiso-C15 : 0. The novel strain contained diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol as predominant polar lipids, and the main respiratory isoprenoid quinone was MK-8. Based on the 16S rRNA phylogenetic analysis, together with MLSA (recA, rpoB and gyrB), phylogenomic, chemotaxonomic and phenotypic results, we demonstrate that strain Z8T represents a novel species of the genus Psychrobacillus, for which the name Psychrobacillus vulpis sp. nov., is proposed. The type strain is Z8T (=CECT 9721T=LMG 31001T).
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Affiliation(s)
- Miguel Rodríguez
- Biomedical Research Center (CIBM), Biotechnology Institute, Parque Tecnológico Ciencias de la Salud (PTS), Avenida del Conocimiento s/n, 18100, Armilla, Granada, Spain.,Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario Cartuja s/n, 18071 Granada, Spain
| | - José Carlos Reina
- Biomedical Research Center (CIBM), Biotechnology Institute, Parque Tecnológico Ciencias de la Salud (PTS), Avenida del Conocimiento s/n, 18100, Armilla, Granada, Spain.,Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario Cartuja s/n, 18071 Granada, Spain
| | - Victoria Béjar
- Biomedical Research Center (CIBM), Biotechnology Institute, Parque Tecnológico Ciencias de la Salud (PTS), Avenida del Conocimiento s/n, 18100, Armilla, Granada, Spain.,Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario Cartuja s/n, 18071 Granada, Spain
| | - Inmaculada Llamas
- Biomedical Research Center (CIBM), Biotechnology Institute, Parque Tecnológico Ciencias de la Salud (PTS), Avenida del Conocimiento s/n, 18100, Armilla, Granada, Spain.,Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario Cartuja s/n, 18071 Granada, Spain
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Reina JC, Pérez-Victoria I, Martín J, Llamas I. A Quorum-Sensing Inhibitor Strain of Vibrio alginolyticus Blocks Qs-Controlled Phenotypes in Chromobacterium violaceum and Pseudomonas aeruginosa. Mar Drugs 2019; 17:md17090494. [PMID: 31450549 PMCID: PMC6780304 DOI: 10.3390/md17090494] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/14/2019] [Accepted: 08/22/2019] [Indexed: 12/11/2022] Open
Abstract
The cell density-dependent mechanism, quorum sensing (QS), regulates the expression of virulence factors. Its inhibition has been proposed as a promising new strategy to prevent bacterial pathogenicity. In this study, 827 strains from the microbiota of sea anemones and holothurians were screened for their ability to produce quorum-sensing inhibitor (QSI) compounds. The strain M3-10, identified as Vibrio alginolyticus by 16S rRNA gene sequencing, as well as ANIb and dDDH analyses, was selected for its high QSI activity. Bioassay-guided fractionation of the cell pellet extract from a fermentation broth of strain M3-10, followed by LC–MS and NMR analyses, revealed tyramine and N-acetyltyramine as the active compounds. The QS inhibitory activity of these molecules, which was confirmed using pure commercially available standards, was found to significantly inhibit Chromobacterium violaceum ATCC 12472 violacein production and virulence factors, such as pyoverdine production, as well as swarming and twitching motilities, produced by Pseudomonas aeruginosa PAO1. This constitutes the first study to screen QSI-producing strains in the microbiota of anemones and holothurians and provides an insight into the use of naturally produced QSI as a possible strategy to combat bacterial infections.
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Affiliation(s)
- José Carlos Reina
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario Cartuja s/n, 18071 Granada, Spain
| | - Ignacio Pérez-Victoria
- MEDINA Foundation, Andalusian Center of Excellence for Research into Innovative Medicines, Health Sciences Technological Park (PTS), Avda. del Conocimiento 34, 18016 Armilla, Granada, Spain.
| | - Jesús Martín
- MEDINA Foundation, Andalusian Center of Excellence for Research into Innovative Medicines, Health Sciences Technological Park (PTS), Avda. del Conocimiento 34, 18016 Armilla, Granada, Spain
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario Cartuja s/n, 18071 Granada, Spain.
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, 18100 Granada, Spain.
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Tena-Garitaonaindia M, Llamas I, Toral L, Sampedro I. Chemotaxis of halophilic bacterium Halomonas anticariensis FP35 towards the environmental pollutants phenol and naphthalene. Sci Total Environ 2019; 669:631-636. [PMID: 30889450 DOI: 10.1016/j.scitotenv.2019.02.444] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/27/2019] [Accepted: 02/27/2019] [Indexed: 06/09/2023]
Abstract
Chemotaxis can play an important role in bioremediation and substrate bioavailability. The bioremediation of hydrocarbons in saline environments can be carried out by technologies using halophilic bacteria. The aim of this study is to analyse chemotactic responses of the halophilic bacterium Halomonas anticariensis FP35T to environmental pollutants, as well as its catabolic potential for biotechnological use in bioremediation processes under saline conditions. Chemotaxis was detected and quantified using a modified Adler capillary assay. PCR amplification with degenerate primers for genes encoding ring-cleaving enzymes was used to characterize the catabolic versatility of FP35T. The results indicate that phenol (100-1,000 ppm) and naphthalene (100-500 ppm) are chemoattractants for H. anticariensis FP35T in a dose-dependent manner. These hydrocarbons were observed to act as chemoattractants for FP35T grown in a wide range of sea salt solutions (5-12.5% (w/v). However, the 7.5% (w/v) saline concentration was found to have the strongest chemotactic response. We also detected genes encoding ring-cleaving enzymes in the β-ketoadipate pathway for aromatic catabolism. These results suggest that H. anticariensis FP35T has the potential to catabolize aromatic compounds and to be used in bioremediation processes under saline conditions.
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Affiliation(s)
- M Tena-Garitaonaindia
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, 18071 Granada, Spain; Biomedical Research Center (CIBM), Institute of Biotechnology, Avenida del Conocimiento s/n, 18100 Armilla, Granada, Spain
| | - I Llamas
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, 18071 Granada, Spain; Biomedical Research Center (CIBM), Institute of Biotechnology, Avenida del Conocimiento s/n, 18100 Armilla, Granada, Spain
| | - L Toral
- Xtrem Biotech S.L., European Business Innovation Center, Avenida de la Innovación, 1, 18016 Armilla, Granada, Spain
| | - I Sampedro
- Department of Microbiology, Faculty of Pharmacy, Campus de Cartuja s/n, 18071 Granada, Spain; Biomedical Research Center (CIBM), Institute of Biotechnology, Avenida del Conocimiento s/n, 18100 Armilla, Granada, Spain.
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Reina JC, Torres M, Llamas I. Stenotrophomonas maltophilia AHL-Degrading Strains Isolated from Marine Invertebrate Microbiota Attenuate the Virulence of Pectobacterium carotovorum and Vibrio coralliilyticus. Mar Biotechnol (NY) 2019; 21:276-290. [PMID: 30762152 DOI: 10.1007/s10126-019-09879-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/21/2019] [Indexed: 06/09/2023]
Abstract
Many Gram-negative aquacultural and agricultural pathogens control virulence factor expression through a quorum-sensing (QS) mechanism involving the production of N-acylhomoserine (AHL) signalling molecules. Thus, the interruption of QS systems by the enzymatic degradation of signalling molecules, known as quorum quenching (QQ), has been proposed as a novel strategy to combat these infections. Given that the symbiotic bacteria of marine invertebrates are considered to be an important source of new bioactive molecules, this study explores the presence of AHL-degrading bacteria among 827 strains previously isolated from the microbiota of anemones and holothurians. Four of these strains (M3-1, M1-14, M3-13 and M9-54-2), belonging to the species Stenotrophomonas maltophilia, were selected on the basis of their ability to degrade a broad range of AHLs, and the enzymes involved in their activity were identified. Strain M9-54-2, which showed the strongest AHL-degrading activity, was selected for further study. High-performance liquid chromatography-mass-spectrometry confirmed that the QQ enzyme is not a lactonase. Strain M9-54-2 degraded AHL accumulation and reduced the production of enzymatic activity in Pectobacterium carotovorum CECT 225T and Vibrio coralliilyticus VibC-Oc-193 in in vitro co-cultivation experiments. The effect of AHL inactivation was confirmed by a reduction in potato tuber maceration and brine shrimp (Artemia salina) mortality caused by P. carotovorum and Vibrio coralliilyticus, respectively. This study strengthens the evidence of marine organisms as an underexplored and promising source of QQ enzymes, useful to prevent infections in aquaculture and agriculture. To our knowledge, this is the first time that anemones and holothurians have been studied for this purpose.
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Affiliation(s)
- José Carlos Reina
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071, Granada, Spain
| | - Marta Torres
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071, Granada, Spain
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, 18071, Granada, Spain
- Institute for Integrative Biology of the Cell, CEA, CNRS, University Paris-Sud, University Paris-Saclay, Gif sur Yvette, France
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071, Granada, Spain.
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, 18071, Granada, Spain.
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Torres M, Dessaux Y, Llamas I. Saline Environments as a Source of Potential Quorum Sensing Disruptors to Control Bacterial Infections: A Review. Mar Drugs 2019; 17:md17030191. [PMID: 30934619 PMCID: PMC6471967 DOI: 10.3390/md17030191] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/19/2019] [Accepted: 03/20/2019] [Indexed: 12/12/2022] Open
Abstract
Saline environments, such as marine and hypersaline habitats, are widely distributed around the world. They include sea waters, saline lakes, solar salterns, or hypersaline soils. The bacteria that live in these habitats produce and develop unique bioactive molecules and physiological pathways to cope with the stress conditions generated by these environments. They have been described to produce compounds with properties that differ from those found in non-saline habitats. In the last decades, the ability to disrupt quorum-sensing (QS) intercellular communication systems has been identified in many marine organisms, including bacteria. The two main mechanisms of QS interference, i.e., quorum sensing inhibition (QSI) and quorum quenching (QQ), appear to be a more frequent phenomenon in marine aquatic environments than in soils. However, data concerning bacteria from hypersaline habitats is scarce. Salt-tolerant QSI compounds and QQ enzymes may be of interest to interfere with QS-regulated bacterial functions, including virulence, in sectors such as aquaculture or agriculture where salinity is a serious environmental issue. This review provides a global overview of the main works related to QS interruption in saline environments as well as the derived biotechnological applications.
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Affiliation(s)
- Marta Torres
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain.
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, 18100 Granada, Spain.
- Institute for Integrative Biology of the Cell (I2BC), CEA/CNRS/University Paris-Sud, University Paris-Saclay, 91198 Gif-sur-Yvette, France.
| | - Yves Dessaux
- Institute for Integrative Biology of the Cell (I2BC), CEA/CNRS/University Paris-Sud, University Paris-Saclay, 91198 Gif-sur-Yvette, France.
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain.
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, 18100 Granada, Spain.
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Torres M, Hong KW, Chong TM, Reina JC, Chan KG, Dessaux Y, Llamas I. Genomic analyses of two Alteromonas stellipolaris strains reveal traits with potential biotechnological applications. Sci Rep 2019; 9:1215. [PMID: 30718637 PMCID: PMC6361997 DOI: 10.1038/s41598-018-37720-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/27/2018] [Indexed: 11/08/2022] Open
Abstract
The Alteromonas stellipolaris strains PQQ-42 and PQQ-44, previously isolated from a fish hatchery, have been selected on the basis of their strong quorum quenching (QQ) activity, as well as their ability to reduce Vibrio-induced mortality on the coral Oculina patagonica. In this study, the genome sequences of both strains were determined and analyzed in order to identify the mechanism responsible for QQ activity. Both PQQ-42 and PQQ-44 were found to degrade a wide range of N-acylhomoserine lactone (AHL) QS signals, possibly due to the presence of an aac gene which encodes an AHL amidohydrolase. In addition, the different colony morphologies exhibited by the strains could be related to the differences observed in genes encoding cell wall biosynthesis and exopolysaccharide (EPS) production. The PQQ-42 strain produces more EPS (0.36 g l-1) than the PQQ-44 strain (0.15 g l-1), whose chemical compositions also differ. Remarkably, PQQ-44 EPS contains large amounts of fucose, a sugar used in high-value biotechnological applications. Furthermore, the genome of strain PQQ-42 contained a large non-ribosomal peptide synthase (NRPS) cluster with a previously unknown genetic structure. The synthesis of enzymes and other bioactive compounds were also identified, indicating that PQQ-42 and PQQ-44 could have biotechnological applications.
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Affiliation(s)
- Marta Torres
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
- Institute for Integrative Biology of the Cell (I2BC), CEA/CNRS/University Paris-Sud, University Paris-Saclay, Gif-sur-Yvette, France
| | - Kar-Wai Hong
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Teik-Min Chong
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - José Carlos Reina
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Kok-Gan Chan
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
- International Genome Centre, Jiangsu University, Zhenjiang, China
| | - Yves Dessaux
- Institute for Integrative Biology of the Cell (I2BC), CEA/CNRS/University Paris-Sud, University Paris-Saclay, Gif-sur-Yvette, France.
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
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Oueriaghli N, Castro DJ, Llamas I, Béjar V, Martínez-Checa F. Study of Bacterial Community Composition and Correlation of Environmental Variables in Rambla Salada, a Hypersaline Environment in South-Eastern Spain. Front Microbiol 2018; 9:1377. [PMID: 29977233 PMCID: PMC6021518 DOI: 10.3389/fmicb.2018.01377] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 06/06/2018] [Indexed: 12/03/2022] Open
Abstract
We studied the bacterial community in Rambla Salada in three different sampling sites and in three different seasons and the effect of salinity, oxygen, and pH. All sites samples had high diversity and richness (Rr > 30). The diversity indexes and the analysis of dendrograms obtained by DGGE fingerprint after applying Pearson's and Dice's coefficient showed a strong influence of sampling season. The Pareto-Lorenz (PL) curves and Fo analysis indicated that the microbial communities were balanced and despite the changing environmental conditions, they can preserve their functionality. The main phyla detected by DGGE were Bacteroidetes (39.73%), Proteobacteria (28.43%), Firmicutes (8.23%), and Cyanobacteria (5.14%). The majority of the sequences corresponding to uncultured bacteria belonged to Bacteroidetes phylum. Within Proteobacteria, the main genera detected were Halothiobacillus and Roseovarius. The environmental factors which influenced the community in a higher degree were the salinity and oxygen. The bacteria belonging to Bacteroidetes and Proteobacteria were positively influenced by salinity. Nevertheless, bacteria related to Alpha- and Betaproteobacteria classes and phylum Firmicutes showed a positive correlation with oxygen and pH but negative with salinity. The phylum Cyanobacteria were less influenced by the environmental variables. The bacterial community composition of Rambla Salada was also studied by dilution-to-extinction technique. Using this method, 354 microorganisms were isolated. The 16S sequences of 61 isolates showed that the diversity was very different to those obtained by DGGE and with those obtained previously by using classic culture techniques. The taxa identified by dilution-to-extinction were Proteobacteria (81.92%), Firmicutes (11.30%), Actinobacteria (4.52%), and Bacteroidetes (2.26%) phyla with Gammaproteobacteria as predominant class (65.7%). The main genera were: Marinobacter (38.85%), Halomonas (20.2%), and Bacillus (11.2%). Nine of the 61 identified bacteria showed less than 97% sequence identity with validly described species and may well represent new taxa. The number of bacteria in different samples, locations, and seasons were calculated by CARD-FISH, ranging from 54.3 to 78.9% of the total prokaryotic population. In conclusion, the dilution-to-extinction technique could be a complementary method to classical culture based method, but neither gets to cultivate the major taxa detected by DGGE. The bacterial community was influenced significantly by the physico-chemical parameters (specially the salinity and oxygen), the location and the season of sampling.
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Affiliation(s)
- Nahid Oueriaghli
- Microbial Exopolysacharide Research Group, Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - David J. Castro
- Microbial Exopolysacharide Research Group, Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, University of Granada, Granada, Spain
| | - Inmaculada Llamas
- Microbial Exopolysacharide Research Group, Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, University of Granada, Granada, Spain
| | - Victoria Béjar
- Microbial Exopolysacharide Research Group, Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, University of Granada, Granada, Spain
| | - Fernando Martínez-Checa
- Microbial Exopolysacharide Research Group, Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, University of Granada, Granada, Spain
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Torres M, Reina JC, Fuentes-Monteverde JC, Fernández G, Rodríguez J, Jiménez C, Llamas I. AHL-lactonase expression in three marine emerging pathogenic Vibrio spp. reduces virulence and mortality in brine shrimp (Artemia salina) and Manila clam (Venerupis philippinarum). PLoS One 2018; 13:e0195176. [PMID: 29664914 PMCID: PMC5903640 DOI: 10.1371/journal.pone.0195176] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 03/16/2018] [Indexed: 11/19/2022] Open
Abstract
Bacterial infectious diseases produced by Vibrio are the main cause of economic losses in aquaculture. During recent years it has been shown that the expression of virulence genes in some Vibrio species is controlled by a population-density dependent gene-expression mechanism known as quorum sensing (QS), which is mediated by the diffusion of signal molecules such as N-acylhomoserine lactones (AHLs). QS disruption, especially the enzymatic degradation of signalling molecules, known as quorum quenching (QQ), is one of the novel therapeutic strategies for the treatment of bacterial infections. In this study, we present the detection of AHLs in 34 marine Vibrionaceae strains. Three aquaculture-related pathogenic Vibrio strains, V. mediterranei VibC-Oc-097, V. owensii VibC-Oc-106 and V. coralliilyticus VibC-Oc-193 were selected for further studies based on their virulence and high production of AHLs. This is the first report where the signal molecules have been characterized in these emerging marine pathogens and correlated to the expression of virulence factors. Moreover, the results of AHL inactivation in the three selected strains have been confirmed in vivo against brine shrimps (Artemia salina) and Manila clams (Venerupis philippinarum). This research contributes to the development of future therapies based on AHL disruption, the most promising alternatives for fighting infectious diseases in aquaculture.
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Affiliation(s)
- Marta Torres
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
| | - José Carlos Reina
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Juan Carlos Fuentes-Monteverde
- Department of Chemistry, Faculty of Sciences and Center for Advanced Scientific Research (CICA), University of A Coruña, A Coruña, Spain
| | - Gerardo Fernández
- Research Support Service (SAI), Central Services (ESCI) University of A Coruña, A Coruña, Spain
| | - Jaime Rodríguez
- Department of Chemistry, Faculty of Sciences and Center for Advanced Scientific Research (CICA), University of A Coruña, A Coruña, Spain
| | - Carlos Jiménez
- Department of Chemistry, Faculty of Sciences and Center for Advanced Scientific Research (CICA), University of A Coruña, A Coruña, Spain
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
- Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
- * E-mail:
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Castro DJ, Llamas I, Béjar V, Martínez-Checa F. Blastomonas quesadae sp. nov., isolated from a saline soil by dilution-to-extinction cultivation. Int J Syst Evol Microbiol 2017. [PMID: 28631592 DOI: 10.1099/ijsem.0.001902] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We isolated a Gram-stain-negative, aerobic bacterial strain, 912T, from a soil sample taken from Rambla Salada (Murcia), south-eastern Spain, by using the dilution-to-extinction method. Cells of the strain were motile with a polar flagellum, short rod-shaped, catalase- and oxidase-positive and grew at NaCl concentrations within the range 0-5 % (w/v) (optimum 3 %, w/v), at 4-32 °C (optimum 30 °C) and at pH 6-9 (optimum pH 7); bacteriochlorophyll a was produced. Analysis of the 16S rRNA gene sequence indicated that this strain belonged to the genus Blastomonas in the class Alphaproteobacteria. Its closest relatives were Blastomonas natatoria EY 4220T, Blastomonas ursincola KR-99T and Blastomonas aquatica PE 4-5T, to which the strain showed 16S rRNA gene sequence similarity values of 95.9, 95.8 and 95.1 %, respectively. The DNA G+C content was 63 mol%. The major fatty acids of strain 912T were C18 : 1ω7c/C18 : 1ω6c, C16 : 1ω7c/C16 : 1ω6c, C16 : 0 and C17 : 1ω6c. The predominant isoprenoid quinone was ubiquinone 10 (Q-10). The polar lipids contained diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid, phosphoglycolipid, one unidentified phospholipid and two unidentified polar lipids. Based on the phylogenetic, genotypic, phenotypic and chemotaxonomic data, the strain represents a novel species of the genus Blastomonas, for which the name Blastomonas quesadae sp. nov. is proposed. Strain 912T (=CECT 9186T=LMG 29921T) is the type strain.
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Affiliation(s)
- David J Castro
- Institute of Biotechnology, Centre for Biomedical Research, University of Granada, Spain.,Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Inmaculada Llamas
- Institute of Biotechnology, Centre for Biomedical Research, University of Granada, Spain.,Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Victoria Béjar
- Institute of Biotechnology, Centre for Biomedical Research, University of Granada, Spain.,Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Fernando Martínez-Checa
- Institute of Biotechnology, Centre for Biomedical Research, University of Granada, Spain.,Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
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Torres M, Uroz S, Salto R, Fauchery L, Quesada E, Llamas I. HqiA, a novel quorum-quenching enzyme which expands the AHL lactonase family. Sci Rep 2017; 7:943. [PMID: 28424524 PMCID: PMC5430456 DOI: 10.1038/s41598-017-01176-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 03/22/2017] [Indexed: 11/09/2022] Open
Abstract
The screening of a metagenomic library of 250,000 clones generated from a hypersaline soil (Spain) allowed us to identify a single positive clone which confers the ability to degrade N-acyl homoserine lactones (AHLs). The sequencing of the fosmid revealed a 42,318 bp environmental insert characterized by 46 ORFs. The subcloning of these ORFs demonstrated that a single gene (hqiA) allowed AHL degradation. Enzymatic analysis using purified HqiA and HPLC/MS revealed that this protein has lactonase activity on a broad range of AHLs. The introduction of hqiA in the plant pathogen Pectobacterium carotovorum efficiently interfered with both the synthesis of AHLs and quorum-sensing regulated functions, such as swarming motility and the production of maceration enzymes. Bioinformatic analyses highlighted that HqiA showed no sequence homology with the known prototypic AHL lactonases or acylases, thus expanding the AHL-degrading enzymes with a new family related to the cysteine hydrolase (CHase) group. The complete sequence analysis of the fosmid showed that 31 ORFs out of the 46 identified were related to Deltaproteobacteria, whilst many intercalated ORFs presented high homology with other taxa. In this sense, hqiA appeared to be assigned to the Hyphomonas genus (Alphaproteobacteria), suggesting that horizontal gene transfer had occurred.
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Affiliation(s)
- Marta Torres
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain.,Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
| | - Stéphane Uroz
- UMR 1136 INRA-Université de Lorraine Interactions Arbres-Microorganismes, Centre INRA de Nancy, Champenoux, France
| | - Rafael Salto
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Laure Fauchery
- UMR 1136 INRA-Université de Lorraine Interactions Arbres-Microorganismes, Centre INRA de Nancy, Champenoux, France
| | - Emilia Quesada
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain.,Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain. .,Institute of Biotechnology, Biomedical Research Center (CIBM), University of Granada, Granada, Spain.
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Torres M, Rubio-Portillo E, Antón J, Ramos-Esplá AA, Quesada E, Llamas I. Selection of the N-Acylhomoserine Lactone-Degrading Bacterium Alteromonas stellipolaris PQQ-42 and of Its Potential for Biocontrol in Aquaculture. Front Microbiol 2016; 7:646. [PMID: 27242684 PMCID: PMC4860449 DOI: 10.3389/fmicb.2016.00646] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/18/2016] [Indexed: 12/26/2022] Open
Abstract
The production of virulence factors by many pathogenic microorganisms depends on the intercellular communication system called quorum sensing, which involves the production and release of signal molecules known as autoinducers. Based on this, new-therapeutic strategies have emerged for the treatment of a variety of infections, such as the enzymatic degradation of signaling molecules, known as quorum quenching (QQ). In this study, we present the screening of QQ activity amongst 450 strains isolated from a bivalve hatchery in Granada (Spain), and the selection of the strain PQQ-42, which degrades a wide range of N-acylhomoserine lactones (AHLs). The selected strain, identified as Alteromonas stellipolaris, degraded the accumulation of AHLs and reduced the production of protease and chitinase and swimming motility of a Vibrio species in co-cultivation experiments in vitro. In the bio-control experiment, strain PQQ-42 significantly reduced the pathogenicity of Vibrio mediterranei VibC-Oc-097 upon the coral Oculina patagonica showing a lower degree of tissue damage (29.25 ± 14.63%) in its presence, compared to when the coral was infected with V. mediterranei VibC-Oc-097 alone (77.53 ± 13.22%). Our results suggest that this AHL-degrading bacterium may have biotechnological applications in aquaculture.
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Affiliation(s)
- Marta Torres
- Faculty of Pharmacy, Department of Microbiology, University of GranadaGranada, Spain; Biomedical Research Centre (CIBM), Institute of Biotechnology, University of GranadaGranada, Spain
| | - Esther Rubio-Portillo
- Department of Marine Science and Applied Biology, University of Alicante Alicante, Spain
| | - Josefa Antón
- Department of Physiology, Genetics and Microbiology, University of Alicante Alicante, Spain
| | - Alfonso A Ramos-Esplá
- Department of Marine Science and Applied Biology, University of Alicante Alicante, Spain
| | - Emilia Quesada
- Faculty of Pharmacy, Department of Microbiology, University of GranadaGranada, Spain; Biomedical Research Centre (CIBM), Institute of Biotechnology, University of GranadaGranada, Spain
| | - Inmaculada Llamas
- Faculty of Pharmacy, Department of Microbiology, University of GranadaGranada, Spain; Biomedical Research Centre (CIBM), Institute of Biotechnology, University of GranadaGranada, Spain
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León MJ, Sánchez-Porro C, de la Haba RR, Llamas I, Ventosa A. Corrigendum to “Larsenia salina gen. nov., sp. nov., a new member of the family Halomonadaceae based on multilocus sequence analysis” [Syst. Appl. Microbiol. 37 (October (7)) (2014) 480–487]. Syst Appl Microbiol 2015. [DOI: 10.1016/j.syapm.2014.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
In this study we analyzed the diversity of the halophilic bacteria community from Rambla Salada during the years 2006 and 2007. We collected a total of 364 strains, which were then identified by means of phenotypic tests and by the hypervariable V1–V3 region of the 16S rRNA sequences (around 500 bp). The ribosomal data showed that the isolates belonged to Proteobacteria (72.5%), Firmicutes (25.8%), Actinobacteria (1.4%), and Bacteroidetes (0.3%) phyla, with Gammaproteobacteria the predominant class. Halomonas was the most abundant genus (41.2% isolates) followed by Marinobacter (12.9% isolates) and Bacillus (12.6% isolates). In addition, 9 strains showed <97% sequence identity with validly described species and may well represent new taxa. The diversity of the bacterial community analyzed with the DOTUR package determined 139 operational taxonomic units at 3% genetic distance level. Rarefaction curves and diversity indexes demonstrated that our collection of isolates adequately represented all the bacterial community at Rambla Salada that can be grown under the conditions used in this work. We found that the sampling season influenced the composition of the bacterial community, and bacterial diversity was higher in 2007; this fact could be related to lower salinity at this sampling time.
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Affiliation(s)
- Rocío Luque
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario Cartuja s/n, 18071 Granada, Spain; Institute of Biotechnology, University of Granada, Granada, Spain
| | - Victoria Béjar
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario Cartuja s/n, 18071 Granada, Spain; Institute of Biotechnology, University of Granada, Granada, Spain
| | - Emilia Quesada
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario Cartuja s/n, 18071 Granada, Spain; Institute of Biotechnology, University of Granada, Granada, Spain
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario Cartuja s/n, 18071 Granada, Spain; Institute of Biotechnology, University of Granada, Granada, Spain
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Torres M, Romero M, Prado S, Dubert J, Tahrioui A, Otero A, Llamas I. N-acylhomoserine lactone-degrading bacteria isolated from hatchery bivalve larval cultures. Microbiol Res 2013; 168:547-54. [PMID: 23743010 DOI: 10.1016/j.micres.2013.04.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 04/26/2013] [Accepted: 04/27/2013] [Indexed: 10/26/2022]
Abstract
Quorum sensing (QS) systems, which depend on N-acylhomoserine lactone (AHL) signal molecules, mediate the production of virulence factors in many pathogenic microorganisms. One hundred and forty-six bacterial strains, isolated from a bivalve hatchery, were screened for their capacity to degrade five synthetic AHLs [N-butyryl-DL-homoserine lactone (C4-HSL), N-hexanoyl-DL-homoserine lactone (C6-HSL), N-octanoyl-DL-homoserine lactone (C8-HSL), N-decanoyl-DL-homoserine lactone (C10-HSL) and N-dodecanoyl-DL-homoserine lactone (C12-HSL)] using well diffusion agar-plate assays with three biosensors, Chromobacterium violaceum CV026, C. violaceum VIR07 and Agrobacterium tumefaciens NTL4 (pZLR4). The results of these assays led to our choosing four strains (PP2-67, PP2-459, PP2-644 and PP2-663) that were able to degrade all five synthetic AHLs, thus showing a wide spectrum of quorum quenching (QQ) activity. We subsequently confirmed and measured the QQ activity of the four strains by high-performance liquid chromatography plus mass-spectrometry analysis (HPLC-MS). One of the strains which showed the highest AHL-degrading activity, PP2-459, identified as being a member of the genus Thalassomonas was chosen for further study. Finally, using thin-layer chromatography (TLC), we went on to confirm this strain's capacity to degrade the AHLs produced by other non-pathogenic and pathogenic bacteria not taxonomically related.
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Affiliation(s)
- Marta Torres
- Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
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Tahrioui A, Quesada E, Llamas I. Genetic and phenotypic analysis of the GacS/GacA system in the moderate halophile Halomonas anticariensis. Microbiology (Reading) 2013; 159:462-474. [DOI: 10.1099/mic.0.061721-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
- Ali Tahrioui
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071 Granada, Spain
| | - Emilia Quesada
- Biotechnology Research Institute, Polígono Universitario de Fuentenueva, University of Granada, 18071 Granada, Spain
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071 Granada, Spain
| | - Inmaculada Llamas
- Biotechnology Research Institute, Polígono Universitario de Fuentenueva, University of Granada, 18071 Granada, Spain
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071 Granada, Spain
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Luque R, Béjar V, Quesada E, Martínez-Checa F, Llamas I. Halomonas ramblicola sp. nov., a moderately halophilic bacterium from Rambla Salada, a Mediterranean hypersaline rambla. Int J Syst Evol Microbiol 2012; 62:2903-2909. [DOI: 10.1099/ijs.0.039453-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A moderately halophilic bacterium (strain RS-16T) was isolated from saline soil in Rambla Salada, a Mediterranean hypersaline rambla in Murcia, south-east Spain. Cells of strain RS-16T were Gram-negative rods, oxidase-negative and motile by peritrichous flagella. Strain RS-16T required NaCl for growth, and grew between 1 % and 30 % (w/v) NaCl (optimum, 5–7.5 %), at temperatures of between 4 °C and 41 °C (optimum, 32–37 °C), and at pH values of between 5 and 10 (optimum, pH 7). Strain RS-16T was chemo-organotrophic and its metabolism was respiratory with oxygen and nitrate as terminal electron acceptors. It produced acids from d-glucose and myo-inositol, accumulated poly-β-hydroxyalkanoate granules and produced cream colonies on MY 7.5 % (w/v). The DNA G+C content of strain RS-16T was 56.2 mol%. A comparison of 16S rRNA gene sequences confirmed the relationship of strain RS-16T to species of the genus
Halomonas
. The most phylogenetically related species was
Halomonas cerina
SP4T (97.4 %16S rRNA gene sequence similarity). In DNA–DNA hybridization assays strain RS-16T showed DNA–DNA relatedness values of 62.7±3.09 %, 64.5±1.97 % and 64.7±1.74 % to
Halomonas cerina
CECT 7282T,
Halomonas cerina
CECT 7284 and
Halomonas cerina
CECT 7283, respectively. The major fatty acids of strain RS-16T were C18 : 1ω7c and C16 : 0, and the predominant respiratory lipoquinone was ubiquinone, with nine isoprene units (Q-9). On the basis of these data, strain RS-16T is considered to represent a novel species of the genus
Halomonas
, for which the name Halomonas ramblicola sp. nov. is proposed. The type strain is RS-16T ( = CECT 7896T = LMG 26647T).
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Affiliation(s)
- Rocío Luque
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Victoria Béjar
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Emilia Quesada
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Fernando Martínez-Checa
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Inmaculada Llamas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
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Llamas I, Amjres H, Mata JA, Quesada E, Béjar V. The potential biotechnological applications of the exopolysaccharide produced by the halophilic bacterium Halomonas almeriensis. Molecules 2012; 17:7103-20. [PMID: 22692238 PMCID: PMC6268429 DOI: 10.3390/molecules17067103] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 05/31/2012] [Accepted: 06/05/2012] [Indexed: 11/16/2022] Open
Abstract
We have studied the extracellular polysaccharide (EPS) produced by the type strain, M8(T), of the halophilic bacterium Halomonas almeriensis, to ascertain whether it might have any biotechnological applications. All the cultural parameters tested influenced both bacterial growth and polysaccharide production. EPS production was mainly growth-associated and under optimum environmental and nutritional conditions M8(T) excreted about 1.7 g of EPS per litre of culture medium (about 0.4 g of EPS per gram of dry cell weight). Analysis by anion-exchange chromatography and high-performance size-exclusion chromatography indicated that the exopolysaccharide was composed of two fractions, one of 6.3 × 10(6) and another of 1.5 × 10(4) Daltons. The monosaccharide composition of the high-molecular-weight fraction was mannose (72% w/w), glucose (27.5% w/w) and rhamnose (0.5% w/w). The low-molecular-weight fraction contained mannose (70% w/w) and glucose (30% w/w). The EPS has a substantial protein fraction (1.1% w/w) and was capable of emulsifying several hydrophobic substrates, a capacity presumably related to its protein content. The EPS produced solutions of low viscosity with pseudoplastic behaviour. It also had a high capacity for binding some cations. It contained considerable quantities of sulphates (1.4% w/w), an unusual feature in bacterial polysaccharides. All these characteristics render it potentially useful as a biological agent, bio-detoxifier and emulsifier.
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Affiliation(s)
- Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain.
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Luque R, González-Domenech CM, Llamas I, Quesada E, Béjar V. Diversity of culturable halophilic archaea isolated from Rambla Salada, Murcia (Spain). Extremophiles 2012; 16:205-13. [PMID: 22219037 DOI: 10.1007/s00792-011-0420-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 12/13/2011] [Indexed: 11/26/2022]
Abstract
We have studied the diversity of culturable halophilic Archaea at Rambla Salada, Murcia (south-eastern Spain). We made 8 samplings at different places in this habitat during the years 2006 and 2007 and isolated a total of 49 strains, which were identified by means of phenotypic tests and the hypervariable V1-V3 region of the 16S rRNA gene sequences (around 500 bp). The ribosomal data showed that the isolates belonged to 12 genera within the Halobacteriaceae family, with Haloferax and Natrinema being the most abundant. Five strains showed less than 97% sequence identity with validly described species and may well represent new taxa. All the strains grew best with around 25% w/v salts, required high concentrations of NaCl and magnesium and produced red to pink colonies. They were facultative anaerobes with both respiratory and fermentative metabolisms. The diversity of the archaeal community was analysed with the MOTHUR package. We identified 14 OTUs at the 3% genetic distance level and found quite high diversity. Rarefaction curves of richness estimators and diversity indices demonstrated that our collection of isolates represented the archaeal community at Rambla Salada that can be isolated under the conditions used in this work. This is the first report to be published on the culturable archaea at Rambla Salada, an area of considerable ecological interest.
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Affiliation(s)
- R Luque
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Granada, Spain
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Tahrioui A, Quesada E, Llamas I. The hanR/hanI quorum-sensing system of Halomonas anticariensis, a moderately halophilic bacterium. Microbiology (Reading) 2011; 157:3378-3387. [DOI: 10.1099/mic.0.052167-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Quorum sensing is a cell density-dependent gene expression mechanism found in many Gram-negative bacteria which involves the production of signal molecules such as N-acylhomoserine lactones (AHLs). One significant group of micro-organisms in which quorum sensing has not been previously studied, however, are the moderate halophiles. We describe here the results of our studies of the quorum-sensing system in Halomonas anticariensis FP35T, which is composed of luxR/luxI homologues: hanR (the putative transcriptional regulator gene) and hanI (the autoinducer synthase gene). To understand how the hanR/hanI system is organized and regulated we conducted RT-PCR and quantitative real-time PCR assays. Transcriptional analysis indicated that the hanR and hanI genes are on the same transcript and that their transcription is growth phase-dependent. HanI seems to be the only autoinducer synthase responsible for the synthesis of AHLs by the bacterium, since the inactivation of hanI resulted in the complete loss of its AHLs. We also found that the hanI gene appears to be transcribed from its own promoter and that its expression does not depend upon HanR. This finding was supported by the fact that the FP35hanR mutant showed AHL-producing activity and hanI expression similar to that of the wild-type strain, the latter being measured by RT-PCR. Moreover, hanR is expressed from its own promoter and appears to be independent of the AHL signalling molecules produced by HanI.
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Affiliation(s)
- Ali Tahrioui
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Emilia Quesada
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Inmaculada Llamas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
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Amjres H, Béjar V, Quesada E, Abrini J, Llamas I. Halomonas rifensis sp. nov., an exopolysaccharide-producing, halophilic bacterium isolated from a solar saltern. Int J Syst Evol Microbiol 2011; 61:2600-2605. [DOI: 10.1099/ijs.0.027268-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
A polyphasic taxonomic study was conducted on strain HK31T, a moderately halophilic bacterium isolated from a solar saltern in Chefchaouen, Morocco. The strain was a Gram-reaction-negative, oxidase-positive rod, which was motile by means of peritrichous flagella. The strain required NaCl for growth and grew in salt concentrations (mixture of sea salts) of 0.5–20 % (w/v) (optimum 5–7.5 %, w/v), at 25–45 °C (optimum 32 °C) and at pH 5–10 (optimum pH 6–9). Strain HK31T did not produce acids from sugars and its metabolism was respiratory, using oxygen as terminal electron acceptor. The strain was positive for the accumulation of poly-β-hydroxyalkanoate granules and formed mucoid colonies due to the excretion of an exopolysaccharide. The DNA G+C content was 61.5 mol%. 16S rRNA gene sequence analysis indicated that it belonged to the genus Halomonas in the class Gammaproteobacteria. The most phylogenetically related species was Halomonas anticariensis, with which strain HK31T showed a 16S rRNA gene sequence similarity of 96.48 %. Its major fatty acids were C18 : 1ω7c, C16 : 0, C19 : 0 cyclo ω8c , C16 : 1ω7c/iso-C15 : 0 2-OH and C12 : 0 3-OH and the predominant respiratory lipoquinone was ubiquinone with nine isoprene units (Q-9). Based on the evidence provided in this study, strain HK31T ( = CECT 7698T = LMG 25695T) represents a novel species of the genus Halomonas, for which the name Halomonas rifensis is proposed.
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Affiliation(s)
- Hakima Amjres
- Biotechnology and Applied Microbiology Research Group, Department of Biology, Faculty of Sciences, University Abdelmalek Essâadi, BP2121, 93002 Tetouan, Morocco
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Victoria Béjar
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Emilia Quesada
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Jamal Abrini
- Biotechnology and Applied Microbiology Research Group, Department of Biology, Faculty of Sciences, University Abdelmalek Essâadi, BP2121, 93002 Tetouan, Morocco
| | - Inmaculada Llamas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
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Llamas I, Béjar V, Martínez-Checa F, Martínez-Cánovas MJ, Molina I, Quesada E. Halomonas stenophila sp. nov., a halophilic bacterium that produces sulphate exopolysaccharides with biological activity. Int J Syst Evol Microbiol 2011; 61:2508-2514. [DOI: 10.1099/ijs.0.026369-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have undertaken a polyphasic taxonomic study of two halophilic, Gram-negative bacterial strains, N12T and B-100, that produce sulphated exopolysaccharides with biological activity. They were isolated from two different saline soil samples. Both strains grow at NaCl concentrations within the range 3–15 % (w/v) [optimum 5–10 % (w/v)], at 15–37 °C (optimum 20–32 °C) and at pH 6–8 (optimum pH 7–8). Their 16S rRNA gene sequences indicate that they belong to the genus Halomonas in the class Gammaproteobacteria. Their closest relative is Halomonas nitroreducens, to which our strains show maximum 16S rRNA gene sequence similarity values of 98.7 % (N12T) and 98.3 % (B-100). Their DNA G+C contents are 61.9 and 63.8 mol%, respectively. The results of DNA–DNA hybridizations showed 43.9 % relatedness between strain N12T and H. nitroreducens CECT 7281T, 30.5 % between N12T and Halomonas ventosae CECT 5797T, 39.2 % between N12T and Halomonas fontilapidosi CECT 7341T, 46.3 % between N12T and Halomonas maura CECT 5298T, 52.9 % between N12T and Halomonas saccharevitans LMG 23976T, 51.3 % between N12T and Halomonas koreensis JCM 12237T and 100 % between strains N12T and B-100. The major fatty acids of strain N12T are C12 : 0 3-OH (5.42 %), C15 : 0 iso 2-OH/C16 : 1ω7c (17.37 %), C16 : 0 (21.62 %) and C18 : 1ω7c (49.19 %). The proposed name for the novel species is Halomonas stenophila sp. nov. Strain N12T ( = CECT 7744T = LMG 25812T) is the type strain.
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Affiliation(s)
- Inmaculada Llamas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Victoria Béjar
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Fernando Martínez-Checa
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - María José Martínez-Cánovas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Ignacio Molina
- Institute of Biopathology and Regenerative Medicine, Centre for Biomedical Research, University of Granada, Spain
| | - Emilia Quesada
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
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Ruiz-Ruiz C, Srivastava GK, Carranza D, Mata JA, Llamas I, Santamaría M, Quesada E, Molina IJ. An exopolysaccharide produced by the novel halophilic bacterium Halomonas stenophila strain B100 selectively induces apoptosis in human T leukaemia cells. Appl Microbiol Biotechnol 2010; 89:345-55. [PMID: 20890756 DOI: 10.1007/s00253-010-2886-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 09/14/2010] [Accepted: 09/15/2010] [Indexed: 11/26/2022]
Abstract
Microbial exopolysaccharides (EPSs) are highly heterogeneous polymers produced by fungi and bacteria and have recently been attracting considerable attention from biotechnologists because of their potential applications in many fields, including biomedicine. We have screened the antitumoural activity of a panel of sulphated EPSs produced by a newly discovered species of halophilic bacteria. We found that the novel halophilic bacterium Halomonas stenophila strain B100 produced a heteropolysaccharide that, when oversulphated, exerted antitumoural activity on T cell lines deriving from acute lymphoblastic leukaemia (ALL). Only tumour cells were susceptible to apoptosis induced by the sulphated EPS (B100S), whilst primary T cells were resistant. Moreover, freshly isolated primary cells from the blood of patients with ALL were also susceptible to B100S-induced apoptosis. The newly discovered B100S is therefore the first bacterial EPS that has been demonstrated to exert a potent and selective pro-apoptotic effect on T leukaemia cells, and thus, we propose that the search for new antineoplastic drugs should include the screening of other bacterial EPSs, particularly those isolated from halophiles.
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Affiliation(s)
- Carmen Ruiz-Ruiz
- Institute of Biopathology and Regenerative Medicine, Centre for Biomedical Research, University of Granada Health-Sciences Technology Park, Avda. del Conocimiento s/n, 18100, Armilla-Granada, Spain
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Mata J, Bjar V, Bressollier P, Tallon R, Urdaci M, Quesada E, Llamas I. Characterization of exopolysaccharides produced by three moderately halophilic bacteria belonging to the family Alteromonadaceae. J Appl Microbiol 2008; 105:521-8. [DOI: 10.1111/j.1365-2672.2008.03789.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Mata JA, Béjar V, Llamas I, Arias S, Bressollier P, Tallon R, Urdaci MC, Quesada E. Exopolysaccharides produced by the recently described halophilic bacteria Halomonas ventosae and Halomonas anticariensis. Res Microbiol 2006; 157:827-35. [PMID: 17005380 DOI: 10.1016/j.resmic.2006.06.004] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 06/06/2006] [Accepted: 06/19/2006] [Indexed: 12/01/2022]
Abstract
We studied exopolysaccharides (EPSs) produced by Halomonas ventosae and Halomonas anticariensis, two novel species of halophilic bacteria. Under optimum environmental and nutritional conditions, H. ventosae strains Al12(T) and Al16 excreted 28.35 mg and 28.95 mg of EPS per 100 ml of culture medium (34.55 and 38.6 mg of EPS per gram of dry cell weight) respectively. The molecular masses of the polymers were about 50 kDa and their main components were glucose, mannose and galactose. They had high protein fractions and showed emulsifying activity on several hydrophobic substrates. Under optimum environmental and nutritional conditions, H. anticariensis strains FP35(T) and FP36 excreted about 29.65 and 49.95 mg of EPS per 100 ml of culture medium (43.6 and 50.95 mg of EPS per gram of dry cell weight) respectively. The molecular masses of the polymers were about 20 and 46 kDa respectively and were composed mainly of glucose, mannose and galacturonic acid. All EPSs produced solutions of low viscosity and pseudoplastic behaviour. They also had a high capacity for binding cations and incorporated considerable quantities of sulphates, which is highly unusual in bacterial polysaccharides. All strains assayed formed biofilms both in polystyrene wells and borosilicate test tubes.
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Affiliation(s)
- Juan Antonio Mata
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
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Llamas I, del Moral A, Martínez-Checa F, Arco Y, Arias S, Quesada E. Halomonas maura is a physiologically versatile bacterium of both ecological and biotechnological interest. Antonie Van Leeuwenhoek 2006; 89:395-403. [PMID: 16622791 DOI: 10.1007/s10482-005-9043-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/21/2005] [Indexed: 11/27/2022]
Abstract
Halomonas maura is a bacterium of great metabolic versatility. We summarise in this work some of the properties that make it a very interesting microorganism both from an ecological and biotechnological point of view. It plays an active role in the nitrogen cycle, is capable of anaerobic respiration in the presence of nitrate and has recently been identified as a diazotrophic bacterium. Of equal interest is mauran, the exopolysaccharide produced by H. maura, which contributes to the formation of biofilms and thus affords the bacterium advantages in the colonisation of its saline niches. Mauran is highly viscous, shows thixotropic and pseudoplastic behaviour, has the capacity to capture heavy metals and exerts a certain immunomodulator effect in medicine. All these attributes have prompted us to make further investigations into its molecular characteristics. To date we have described 15 open reading frames (ORF's) related to exopolysaccharide production, nitrogen fixation and nitrate reductase activity among others.
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Affiliation(s)
- Inmaculada Llamas
- Department of Microbiology, University of Granada, Campus Universitario de Cartuja s/n, 18071, Granada, Spain
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Argandoña M, Martínez-Checa F, Llamas I, Arco Y, Quesada E, del Moral A. A membrane-bound nitrate reductase encoded by the narGHJI operon is responsible for anaerobic respiration in Halomonas maura. Extremophiles 2006; 10:411-9. [PMID: 16612553 DOI: 10.1007/s00792-006-0515-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Accepted: 01/11/2006] [Indexed: 10/24/2022]
Abstract
The halophilic bacterium Halomonas maura is capable of anaerobic respiration on nitrates. By insertional mutagenesis with the minitransposon Tn-5 we obtained the mutant Tc62, which was incapable of anaerobic respiration on nitrates. An analysis of the regions adjacent to the transposon allowed us to characterize the membrane-bound anaerobic-respiratory nitrate reductase narGHJI gene cluster in H. maura. We identified consensus sequences for fumarate and nitrate reductase regulator (FNR)-like protein-binding sites in the promoter regions of the nar genes and consensus sequences corresponding to the NarL binding sites upstream of the nar genes. RT-PCR analysis showed that the narGHJI operon was expressed in response to anaerobic conditions when nitrate was available as electron acceptor. This membrane-bound nitrate reductase is the only enzyme responsible for anaerobic respiration on nitrate in H. maura. In this article we discuss the possible relationship between this enzyme and a dissimilatory nitrate-reduction-to-ammonia process (DNRA) in H. maura and its role in the colonization of the rhizosphere.
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Affiliation(s)
- Montserrat Argandoña
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja s/n, 18071 Granada, Spain
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Llamas I, Moral A, Béjar V, Girón MD, Salto R, Quesada E. Plasmids from Halomonas eurihalina, a microorganism which produces an exopolysaccharide of biotechnological interest. FEMS Microbiol Lett 2006. [DOI: 10.1111/j.1574-6968.1997.tb12736.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Martínez-Checa F, Béjar V, Martínez-Cánovas MJ, Llamas I, Quesada E. Halomonas almeriensis sp. nov., a moderately halophilic, exopolysaccharide-producing bacterium from Cabo de Gata, Almería, south-east Spain. Int J Syst Evol Microbiol 2005; 55:2007-2011. [PMID: 16166703 DOI: 10.1099/ijs.0.63676-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Halomonas almeriensis sp. nov. is a Gram-negative non-motile rod that was isolated from a saltern in the Cabo de Gata-Níjar wildlife reserve in Almería, south-east Spain. It is moderately halophilic, capable of growth at concentrations of 5-25% w/v sea-salt mixture, the optimum being 7.5% w/v. It is chemo-organotrophic and strictly aerobic, produces catalase but not oxidase, does not produce acid from any sugar and does not synthesize hydrolytic enzymes. The most notable difference between this micro-organism and other Halomonas species is that it is very fastidious in its use of a carbon source. It forms mucoid colonies due to the production of an exopolysaccharide. Its G+C content is 63.5 mol%. A comparison of 16S rRNA gene sequences confirmed its relationship to Halomonas species. The most closely related species is Halomonas halmophila with 95.8% similarity between their 16S rRNA gene sequences. DNA-DNA hybridization with H. halmophila is 10.1%. Its major fatty acids are 18:1omega7c, 16:0, 16:1omega7c/15:0 iso 2-OH, 12:0 3-OH, 12:0, 11-methyl 18:1omega7c and 10:0. The proposed name is Halomonas almeriensis sp. nov., with strain M8(T) (=CECT 7050(T)=LMG 22904(T)) as the type strain.
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Affiliation(s)
- Fernando Martínez-Checa
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja s/n, University of Granada, 18071 Granada, Spain
| | - Victoria Béjar
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja s/n, University of Granada, 18071 Granada, Spain
| | - M José Martínez-Cánovas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja s/n, University of Granada, 18071 Granada, Spain
| | - Inmaculada Llamas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja s/n, University of Granada, 18071 Granada, Spain
| | - Emilia Quesada
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja s/n, University of Granada, 18071 Granada, Spain
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Martínez-Checa F, Quesada E, Martínez-Cánovas MJ, Llamas I, Béjar V. Palleronia marisminoris gen. nov., sp. nov., a moderately halophilic, exopolysaccharide-producing bacterium belonging to the ‘Alphaproteobacteria’, isolated from a saline soil. Int J Syst Evol Microbiol 2005; 55:2525-2530. [PMID: 16280521 DOI: 10.1099/ijs.0.63906-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Strain B33T is a moderately halophilic, exopolysaccharide-producing, Gram-negative, non-motile rod isolated from a hypersaline soil bordering a saline saltern on the Mediterranean seaboard in Murcia (Spain). The bacterium is chemoheterotrophic and strictly aerobic. It contains a pink pigment but does not synthesize bacteriochlorophyll a. It requires 0·66 M Na+, 0·1 M Mg2+ and 0·1 M K+ for optimum growth. It does not produce acid from carbohydrates. It cannot grow with carbohydrates, organic acids, sugars, alcohols or amino acids as sole sources of carbon and energy. Its major fatty-acids are 18 : 1ω7c (68·9 %) and 19 : 0 cyclo ω8c (12·8 %). The sole respiratory lipoquinone found in strain B33T is ubiquinone-10. The DNA G+C content is 64·2 mol%. 16S rRNA gene sequence comparisons show that the isolate is a member of the Roseobacter clade within the class ‘Alphaproteobacteria’. The similarity values with Roseivivax halodurans and Roseivivax halotolerans are 88·2 and 88·0 % respectively and 92·2 % with Salipiger mucosus. DNA–DNA hybridization values with these species are <30 %. In the light of the polyphasic evidence gathered in this study it is proposed that the isolate be classified as a novel genus and species with the name Palleronia marisminoris gen. nov., sp. nov. The proposed type strain is strain B33T (=CECT 7066T=LMG 22959T).
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MESH Headings
- Bacteriochlorophyll A/analysis
- Base Composition
- DNA, Bacterial/chemistry
- DNA, Bacterial/isolation & purification
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/isolation & purification
- Fatty Acids/analysis
- Molecular Sequence Data
- Polysaccharides, Bacterial/biosynthesis
- Potassium/metabolism
- Quinones/analysis
- RNA, Ribosomal, 16S/analysis
- RNA, Ribosomal, 16S/genetics
- Rhodobacteraceae/classification
- Rhodobacteraceae/isolation & purification
- Rhodobacteraceae/physiology
- Rhodobacteraceae/ultrastructure
- Saline Solution, Hypertonic/pharmacology
- Sequence Analysis, DNA
- Sodium/metabolism
- Soil Microbiology
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Affiliation(s)
- Fernando Martínez-Checa
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - Emilia Quesada
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - M José Martínez-Cánovas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - Inmaculada Llamas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - Victoria Béjar
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
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Martínez-Checa F, Béjar V, Llamas I, Del Moral A, Quesada E. Alteromonas hispanica sp. nov., a polyunsaturated-fatty-acid-producing, halophilic bacterium isolated from Fuente de Piedra, southern Spain. Int J Syst Evol Microbiol 2005; 55:2385-2390. [PMID: 16280501 DOI: 10.1099/ijs.0.63809-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Strain F-32T, which produces exopolysaccharides and contains polyunsaturated fatty acids, was isolated from a hypersaline water sample collected from Fuente de Piedra (southern Spain). Phylogenetic analyses indicated conclusively that the strain in question belonged to the genus Alteromonas. Phenotypic tests showed that it could be assigned to the genus Alteromonas although it had a number of distinctive characteristics: it is moderately halophilic, growing best with 7·5–10 % w/v NaCl; it grows at 4 °C and produces H2S; it does not grow with d-cellobiose, d-fructose, d-galactose, d-glucose or lactose as sole sources of carbon and energy; and its fatty-acid profile is typical of Alteromonas but it also contains a large amount of an unusual acid with three double bonds [18 : 3ω6c (6, 9, 12); 5·01 %, w/v]. The major isoprenoid quinone is Q8. The DNA G+C content is 46·3 mol%. The phylogenetic, phenotypic and genetic properties of strain F-32T place it within a novel species, for which the name Alteromonas hispanica sp. nov. is proposed. The type strain is F-32T (=CECT 7067T=LMG 22958T).
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Affiliation(s)
- Fernando Martínez-Checa
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Victoria Béjar
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Inmaculada Llamas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Ana Del Moral
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Emilia Quesada
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
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Arco Y, Llamas I, Martínez-Checa F, Argandoña M, Quesada E, Moral AD. epsABCJ genes are involved in the biosynthesis of the exopolysaccharide mauran produced by Halomonas maura. Microbiology (Reading) 2005; 151:2841-2851. [PMID: 16151197 DOI: 10.1099/mic.0.27981-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The moderately halophilic strainHalomonas mauraS-30 produces a high-molecular-mass acidic polymer (4·7×106 Da) composed of repeating units of mannose, galactose, glucose and glucuronic acid. This exopolysaccharide (EPS), known as mauran, has interesting functional properties that make it suitable for use in many industrial fields. Analysis of the flanking regions of a mini-Tn5insertion site in an EPS-deficient mutant ofH. maura, strain TK71, led to the identification of five ORFs (epsABCDJ), which form part of a gene cluster (eps) with the same structural organization as others involved in the biosynthesis of group 1 capsules and some EPSs. Conserved genetic features were found such as JUMPstart andopselements, which are characteristically located preceding the gene clusters for bacterial polysaccharides. On the basis of their amino-acid-sequence homologies, their putative hydropathy profiles and the effect of their mutations, it is predicted that EpsA (an exporter-protein homologue belonging to the OMA family) and EpsC (a chain-length-regulator homologue belonging to the PCP family) play a role in the assembly, polymerization and translocation of mauran. The possibility that mauran might be synthesized via a Wzy-like biosynthesis system, just as it is for many other polysaccharides, is also discussed. This hypothesis is supported by the fact that EpsJ is homologous with some members of the PST-exporter-protein family, which seems to function together with each OMA–PCP pair in polysaccharide transport in Gram-negative bacteria, transferring the assembled lipid-linked repeating units from the cytoplasmic membrane to the periplasmic space. Maximum induction of theepsgenes is reached during stationary phase in the presence of 5 % (w/v) marine salts.
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Affiliation(s)
- Yolanda Arco
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071, Granada, Spain
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071, Granada, Spain
| | - Fernando Martínez-Checa
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071, Granada, Spain
| | - Montserrat Argandoña
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071, Granada, Spain
| | - Emilia Quesada
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071, Granada, Spain
| | - Ana Del Moral
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071, Granada, Spain
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Llamas I, Quesada E, Martínez-Cánovas MJ, Gronquist M, Eberhard A, González JE. Quorum sensing in halophilic bacteria: detection of N-acyl-homoserine lactones in the exopolysaccharide-producing species of Halomonas. Extremophiles 2005; 9:333-41. [PMID: 15909077 DOI: 10.1007/s00792-005-0448-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2004] [Accepted: 03/11/2005] [Indexed: 01/24/2023]
Abstract
Some members of the moderately halophilic genus Halomonas, such as H. eurihalina, H. maura, H. ventosae and H. anticariensis, produce exopolysaccharides with applications in many industrial fields. We report here that these four species also produce autoinducer molecules that are involved in the cell-to-cell signaling process known as quorum sensing. By using the N-acyl homoserine lactone (AHL) indicator strains Agrobacterium tumefaciens NTL4 (pZRL4) and Chromobacterium violaceum CV026, we discovered that all the Halomonas strains examined synthesize detectable AHL signal molecules. The synthesis of these compounds was growth-phase dependent and maximal activity was reached during the late exponential to stationary phases. One of these AHLs seems to be synthesized only in the stationary phase. Some of the AHLs produced by H. anticariens FP35(T) were identified by gas chromatography/mass spectrometry and electrospray ionization tandem mass spectrometry as N-butanoyl homoserine lactone (C(4)-HL), N-hexanoyl homoserine lactone (C(6)-HL), N-octanoyl homoserine lactone (C(8)-HL) and N-dodecanoyl homoserine lactone (C(12)-HL). This study suggests that quorum sensing may also play an important role in extreme environments.
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Affiliation(s)
- Inmaculada Llamas
- Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083-0688, USA
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Ruiz-García C, Quesada E, Martínez-Checa F, Llamas I, Urdaci MC, Béjar V. Bacillus axarquiensis sp. nov. and Bacillus malacitensis sp. nov., isolated from river-mouth sediments in southern Spain. Int J Syst Evol Microbiol 2005; 55:1279-1285. [PMID: 15879268 DOI: 10.1099/ijs.0.63567-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two Gram-positive, rod-shaped, endospore-forming bacteria (strains CR-119T and CR-95T) were isolated from brackish sediments in the mouth of the river Vélez in Málaga, southern Spain, and subjected to a polyphasic taxonomic study. Phenotypic tests showed that these strains were related to other Bacillus species at a similarity level of less than 87·6 %. Both strains are halotolerant, aerobic, chemoheterotrophic, motile with peritrichous flagella and biosurfactant producers. Their endospores are oval, subterminal and non-deforming structures. The predominant menaquinone in both strains is MK-7. The fatty-acid profiles of both strains contain large quantities of branched and saturated fatty acids. The major fatty acids (%) are 15 : 0 anteiso (32·4), 15 : 0 iso (16·8), 17 : 0 iso (13·4), 16 : 0 (11·5) and 17 : 0 anteiso (10·2) in strain CR-119T and 15 : 0 anteiso (37·5), 17 : 0 iso (16·0) and 17 : 0 anteiso (15·8) in strain CR-95T. The G+C contents of strains CR-119T and CR-95T are 41·0 and 42·5 mol%, respectively. RAPD analysis confirmed the low degree of similarity between the two strains and also amongst other Bacillus species. 16S rRNA gene analysis of strain CR-119T showed the highest sequence similarity to be 97·4 %, with Bacillus mojavensis and Bacillus subtilis subsp. spizizenii. In the case of strain CR-95T, the maximum similarity value was 99·5 %, with B. mojavensis. DNA–DNA hybridization of strains CR-119T and CR-95T with the above species produced values lower than 46·9 %. Therefore, on the basis of phenotypic characteristics, phylogenetic data and genomic distinctiveness, we conclude that these Bacillus strains merit classification as novel species, for which we propose the names Bacillus axarquiensis sp. nov. (type strain CR-119T=CECT 5688T=LMG 22476T) and Bacillus malacitensis sp. nov. (type strain CR-95T=CECT 5687T=LMG 22477T).
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MESH Headings
- Aerobiosis
- Bacillus/classification
- Bacillus/cytology
- Bacillus/isolation & purification
- Bacillus/physiology
- Bacterial Typing Techniques
- Base Composition
- DNA Fingerprinting
- DNA, Bacterial/chemistry
- DNA, Bacterial/isolation & purification
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/isolation & purification
- Fatty Acids/analysis
- Fatty Acids/isolation & purification
- Flagella/physiology
- Fresh Water/microbiology
- Genes, rRNA
- Gentian Violet
- Geologic Sediments/microbiology
- Growth Inhibitors/pharmacology
- Molecular Sequence Data
- Movement
- Nucleic Acid Hybridization
- Organic Chemicals/metabolism
- Phenazines
- Phylogeny
- RNA, Bacterial/genetics
- RNA, Ribosomal, 16S/genetics
- Random Amplified Polymorphic DNA Technique
- Sequence Analysis, DNA
- Sodium Chloride/pharmacology
- Spain
- Spores, Bacterial
- Surface-Active Agents/metabolism
- Vitamin K 2/analysis
- Vitamin K 2/isolation & purification
- Water Microbiology
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Affiliation(s)
- Cristina Ruiz-García
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Emilia Quesada
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Fernando Martínez-Checa
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Inmaculada Llamas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
| | - Maria C Urdaci
- Department of Microbiology and Applied Biochemistry, ENITA-Université de Bordeaux, Cours du Général de Gaulle, BP 201, 33175 Gradignan, France
| | - Victoria Béjar
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Cartuja Campus, University of Granada, 18071 Granada, Spain
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Argandoña M, Fernández-Carazo R, Llamas I, Martínez-Checa F, Caba JM, Quesada E, del Moral A. The moderately halophilic bacterium Halomonas maura is a free-living diazotroph. FEMS Microbiol Lett 2005; 244:69-74. [PMID: 15727823 DOI: 10.1016/j.femsle.2005.01.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Revised: 12/22/2004] [Accepted: 01/12/2005] [Indexed: 11/21/2022] Open
Abstract
Halomonas maura is a moderately halophilic bacterium which lives in saline soils and synthesises an exopolysaccharide known as mauran. Strain S-31T grew in a nitrogen-free medium under an N2 atmosphere; the acetylene reduction assay proved positive under specific conditions. We identified the nifH gene in this strain by using degenerate oligonucleotides designed from highly preserved gene sequences obtained from the alignment of a large number of nifH sequences from different microorganisms. Our results lead us to conclude that H. maura is capable of fixing nitrogen under microaerobic conditions.
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Affiliation(s)
- Montserrat Argandoña
- Departamento de Microbiología, Facultad de Farmacia, Campus Universitario de Cartuja s/n., 18071 Granada, Spain
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Ruiz-García C, Béjar V, Martínez-Checa F, Llamas I, Quesada E. Bacillus velezensis sp. nov., a surfactant-producing bacterium isolated from the river Vélez in Málaga, southern Spain. Int J Syst Evol Microbiol 2005; 55:191-195. [PMID: 15653875 DOI: 10.1099/ijs.0.63310-0] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two Gram-positive, endospore-forming bacterial strains, CR-502T and CR-14b, which produce surfactant molecules are described. Phenotypic tests and phylogenetic analyses showed these strains to be members of the genus Bacillus and related to the species Bacillus atrophaeus, Bacillus mojavensis, Bacillus subtilis, Bacillus vallismortis and Bacillus amyloliquefaciens, although they differ from these species in a number of phenotypic characteristics. DNA-DNA hybridization confirmed that they show less than 20 % hybridization with the above-mentioned species and therefore represent a novel species of Bacillus. The DNA G+C content is 46.4 mol% in strain CR-502T and 46.1 mol% in strain CR-14b. The main fatty acids in strain CR-502T are 15 : 0 anteiso (32.70 %), 15 : 0 iso (29.86 %) and 16 : 0 (13.41 %). The main quinone in strain CR-502T is MK-7 (96.6 %). In the light of the polyphasic evidence gathered in this study, it is proposed that these strains be classified as a novel species of the genus Bacillus, with the name Bacillus velezensis sp. nov. The type strain (CR-502T=CECT 5686T=LMG 22478T) was isolated from a brackish water sample taken from the river Vélez at Torredelmar in Málaga, southern Spain.
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Affiliation(s)
- Cristina Ruiz-García
- Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - Victoria Béjar
- Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - Fernando Martínez-Checa
- Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - Emilia Quesada
- Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
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Llamas I, Keshavan N, González JE. Use of Sinorhizobium meliloti as an indicator for specific detection of long-chain N-acyl homoserine lactones. Appl Environ Microbiol 2004; 70:3715-23. [PMID: 15184178 PMCID: PMC427785 DOI: 10.1128/aem.70.6.3715-3723.2004] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Population-density-dependent gene expression in gram-negative bacteria involves the production of signal molecules characterized as N-acyl homoserine lactones (AHLs). The synthesis of AHLs by numerous microorganisms has been identified by using biosensor strains based on the Agrobacterium tumefaciens and Chromobacterium violaceum quorum-sensing systems. The symbiotic nitrogen-fixing bacterium Sinorhizobium meliloti is rapidly becoming a model organism for the study of quorum sensing. This organism harbors at least three different quorum-sensing systems (Sin, Mel, and Tra), which play a role in its symbiotic relationship with its host plant, alfalfa. The Sin system is distinguished among them for the production of long-chain AHLs, including C(18)-HL, the longest AHL reported so far. In this work, we show that construction of a sinI::lacZ transcriptional fusion results in a strain that detects long-chain AHLs with exquisite sensitivity. Overexpression of the SinR regulator protein from a vector promoter increases its sensitivity without loss of specificity. We also show that the resulting indicator strain can recognize long-chain AHLs produced by unrelated bacteria such as Paracoccus denitrificans and Rhodobacter capsulatus. This S. meliloti indicator strain should serve as a tool for the specific detection of long-chain AHLs in new systems.
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Affiliation(s)
- Inmaculada Llamas
- Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, TX 75083-0688, USA
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Martínez-Cánovas MJ, Quesada E, Llamas I, Béjar V. Halomonas ventosae sp. nov., a moderately halophilic, denitrifying, exopolysaccharide-producing bacterium. Int J Syst Evol Microbiol 2004; 54:733-737. [PMID: 15143016 DOI: 10.1099/ijs.0.02942-0] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Halomonas ventosae sp, nov. includes three moderately halophilic, exopolysaccharide-producing strains isolated from saline soils in Jaén (south-eastern Spain). These strains can grow anaerobically using either nitrate or nitrite as terminal electron acceptor and hydrolyse both tyrosine and phenylalanine. Their G+C content varies between 72·6 and 74·3 mol%. The affiliation of the isolates with the genus Halomonas was confirmed by 16S rRNA gene sequence comparison. DNA–DNA hybridization shows 70·4–82·7 % relatedness among the three strains. Nevertheless, their relatedness is less than 43 % compared to related reference strains. The proposed type strain for Halomonas ventosae is strain Al12T (=CECT 5797T=DSM 15911T). It grows best at 8 % (w/v) sea salts and requires the presence of Na+. Its major fatty acids are 18 : 1 ω7c, 16 : 0, 16 : 1 ω7c, and 15 : 0 iso 2-OH. The predominant respiratory lipoquinone found in strain Al12T is ubiquinone with nine isoprene units (Q-9).
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Affiliation(s)
- M José Martínez-Cánovas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - Emilia Quesada
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - Inmaculada Llamas
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
| | - Victoria Béjar
- Microbial Exopolysaccharide Research Group, Department of Microbiology, Faculty of Pharmacy, Campus Universitario de Cartuja, University of Granada, 18071 Granada, Spain
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Abstract
We have discovered that many Halomonas species harbour large extrachromosomal DNA elements. Using currently available protocols it is technically very difficult to identify large plasmids in bacteria, and even more so when they are coated in mucous polysaccharide. We used culture conditions suitable for both halophilic and halophilic exopolysaccharide-producing bacteria and applied a modified gel electrophoresis method to locate and visualise the megaplasmids. Almost all the species of Halomonas studied harbour two plasmids of about 70 kb and 600 kb and some species carry other smaller extrachromosomal DNA elements. The common presence of these megaplasmids may well be related to the survival strategies of the bacteria in their special surroundings.
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Affiliation(s)
- Montserrat Argandoña
- Departamento de Microbiologi;a, Facultad de Farmacia, Campus Universitario de Cartuja s/n, 18071, Granada, Spain.
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Llamas I, Suárez A, Quesada E, Béjar V, del Moral A. Identification and characterization of the carAB genes responsible for encoding carbamoylphosphate synthetase in Halomonas eurihalina. Extremophiles 2003; 7:205-11. [PMID: 12768451 DOI: 10.1007/s00792-002-0311-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2002] [Accepted: 12/02/2002] [Indexed: 10/28/2022]
Abstract
Halomonas eurihalina is a moderately halophilic bacterium which produces exopolysaccharides potentially of great use in many fields of industry and ecology. Strain F2-7 of H. eurihalina synthesizes an anionic exopolysaccharide known as polymer V2-7, which not only has emulsifying activity but also becomes viscous under acidic conditions, and therefore we consider it worthwhile making a detailed study of the genetics of this strain. By insertional mutagenesis using the mini-Tn 5 Km2 transposon we isolated and characterized a mutant strain, S36 K, which requires both arginine and uracil for growth and does not excrete EPS. S36 K carries a mutation within the carB gene that encodes the synthesis of the large subunit of the carbamoylphosphate synthetase enzyme, which in turn catalyzes the synthesis of carbamoylphosphate, an important precursor of arginine and pyrimidines. We describe here the cloning and characterization of the carAB genes, which encode carbamoylphosphate synthetase in Halomonas eurihalina, and discuss this enzyme's possible role in the pathways for the synthesis of exopolysaccharides in strain F2-7.
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Affiliation(s)
- Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, 18071 Granada, Spain
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Abstract
We have studied the genomic organization of Halomonas eurihalina, a moderately halophilic bacterium that produces an anionic exopolysaccharide with a potentially wide range of applications in industry. To estimate the genome size of strain F2-7, large restriction fragments of genomic DNA were separated by pulsed-field gel electrophoresis. According to the average size of the resolved restriction fragments, the genome size of H. eurihalina strain F2-7 was estimated to be around 2500 kb. The physical map of the chromosome for the endonuclease SwaI has been constructed. The F2-7 strain has two plasmids, pVE1 and pVE2, and in this study we have isolated three new plasmids, pVE3, pVE4, and pVE5, of 5.3, 16, and 6.5 kb, respectively, from strains H-1, H-217, and H-236 of H. eurihalina. We have characterized these plasmids and constructed their physical maps. Curing experiments produced no evidence for the involvement of these plasmids in the expression of the mucous phenotype.
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Affiliation(s)
- Inmaculada Llamas
- Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain
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Bouchotroch S, Quesada E, Del Moral A, Llamas I, Béjar V. Halomonas maura sp. nov., a novel moderately halophilic, exopolysaccharide-producing bacterium. Int J Syst Evol Microbiol 2001; 51:1625-1632. [PMID: 11594589 DOI: 10.1099/00207713-51-5-1625] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Four moderately halophilic, exopolysaccharide-producing bacterial strains isolated from soil samples collected from a saltern at Asilah (Morocco) are reported. These four strains were initially considered to belong to the genus Halomonas. Their DNA G+C contents varied between 62.2 and 64.1 mol %. DNA-DNA hybridization revealed a considerable degree of DNA-DNA similarity amongst all four strains (75.5-80.8%). Nevertheless, similarity with the reference strains of phylogenetically close relatives was lower than 40%. 16S rRNA gene sequences were compared with those of other species of Halomonas and other gram-negative bacteria and they were sufficiently distinct phylogenetically from other recognized Halomonas species to warrant their designation as a novel species. The name Halomonas maura sp. nov. is therefore proposed, with strain S-31T (= CECT 5298T= DSM 13445T) as the type strain. The fatty acid composition of strain S-31T revealed the presence of 18:1omega7c, 16:1omega7c/2-OH i15:0 and 16:0 as the major components. Growth rate analysis showed that strain S-31T had specific cationic requirements for Na+ and Mg2+.
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