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Barbeyron T, Le Duff N, Duchaud E, Thomas F. Zobellia alginiliquefaciens sp. nov., a novel member of the flavobacteria isolated from the epibiota of the brown alga Ericaria zosteroides (C. Agardh) Molinari & Guiry 2020. Int J Syst Evol Microbiol 2023; 73. [PMID: 37266991 DOI: 10.1099/ijsem.0.005924] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
Strain LLG6346-3.1T, isolated from the thallus of the brown alga Ericaria zosteroides collected from the Mediterranean Sea near Bastia in Corsica, France, was characterised using a polyphasic method. Cells were Gram-stain-negative, strictly aerobic, non-flagellated, motile by gliding, rod-shaped and grew optimally at 30-33 °C, at pH 8-8.5 and with 4-5 % NaCl. LLG6346-3.1T used the seaweed polysaccharide alginic acid as a sole carbon source which was vigorously liquefied. The results of phylogenetic analyses indicated that the bacterium is affiliated to the genus Zobellia (family Flavobacteriaceae, class Flavobacteriia). LLG6346-3.1T exhibited 16S rRNA gene sequence similarity values of 98.6 and 98.3 % to the type strains of Zobellia russellii and Zobellia roscoffensis, respectively, and of 97.4-98.5 % to members of other species of the genus Zobellia. The DNA G+C content of LLG6346-3.1T was determined to be 38.3 mol%. Digital DNA-DNA hybridisation predictions by the average nucleotide identity (ANI) and genome to genome distance calculator (GGDC) methods between LLG6346-3.1T and other members of the genus Zobellia showed values of 76-88 % and below 37 %, respectively. The results of phenotypic, phylogenetic and genomic analyses indicate that LLG6346-3.1T is distinct from species of the genus Zobellia with validly published names and that it represents a novel species of the genus Zobellia, for which the name Zobellia alginiliquefaciens sp. nov. is proposed. The type strain is LLG6346-3.1T (= RCC7657T = LMG 32918T).
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Affiliation(s)
- Tristan Barbeyron
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680 Roscoff, Brittany, France
| | - Nolwen Le Duff
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680 Roscoff, Brittany, France
| | - Eric Duchaud
- INRAE VIM-UR0892 Molecular Immunology and Virology, research group of Infection and Immunity of Fish, Research Center of Jouy-en-Josas, F-78352 Jouy-en-Josas, Ile-de-France, France
| | - François Thomas
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), 29680 Roscoff, Brittany, France
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Safi AUR, Bendixen E, Rahman H, Khattak B, Wu W, Ullah W, Khan N, Ali F, Yasin N, Qasim M. Molecular identification and differential proteomics of drug resistant Salmonella Typhi. Diagn Microbiol Infect Dis 2023; 105:115883. [PMID: 36731197 DOI: 10.1016/j.diagmicrobio.2022.115883] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 12/04/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022]
Abstract
This study aimed to elucidate differentially expressed proteins in drug resistant Salmonella Typhi. Among 100 samples, S. typhi were identified in 43 samples. In drug susceptibility profile, 95.3% (41/43), 80% (35/43) and 70% (30/43) resistances were observed against Nalidixic acid, Ampicillin, and Chloramphenicol respectively. No resistance was observed against Imipenum and Azithromycin while only 11% (5/43) isolates were found resistant to Ceftriaxone. Mass spectrometric differential analysis resulted in 23 up-regulated proteins in drug resistant isolates. Proteins found up-regulated are involved in virulence (vipB, galU, tufA, and lpp1), translation (rpsF, rpsG, rplJ, and rplR), antibiotic resistance (zwf, phoP, and ompX), cell metabolism (metK, ftsZ, pepD, and secB), stress response (ridA, rbfA, and dps), housekeeping (gapA and eno) and hypothetical proteins including ydfZ, t1802, and yajQ. These proteins are of diverse nature and functions but highly interconnected. Further characterization may be helpful for elucidation of new biomarker proteins and therapeutic drug targets.
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Affiliation(s)
- Aziz Ur Rehman Safi
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan
| | - Emoke Bendixen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C Denmark
| | - Hazir Rahman
- Department of Microbiology, Abdul Wali Khan University Mardan, Mardan Pakistan
| | - Baharullah Khattak
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan
| | - Wei Wu
- College of Animal Sciences and Technology, Southwest University, Chongqing China
| | - Waheed Ullah
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan
| | - Nasar Khan
- Department of Microbiology, Kohsar University Murree, Kashmir Point, Punjab, Pakistan
| | - Farhad Ali
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan
| | - Nusrat Yasin
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan
| | - Muhammad Qasim
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan.
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Sennaj R, Lemriss S, Souiri A, Kabbaj SEL, Chafik A, Essamadi AK, Benali T, Fassouane A, Dari K, Aassila H. Eco-friendly degradation of reactive red 195, reactive blue 214, and reactive yellow 145 by Klebsiella pneumoniae MW815592 isolated from textile waste. J Microbiol Methods 2023; 204:106659. [PMID: 36529157 DOI: 10.1016/j.mimet.2022.106659] [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: 07/31/2022] [Revised: 12/13/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
The water is used in many textile manufacturing steps beyond cleaning. The quantity and the significant chemical load of the effluents generated constitute the primary challenge of the textile industry. In order to discover new sustainable methods to overcome this problem, the aim of this research was to study the potential for degradation of Reactive Blue 214, Reactive Red 195, and Reactive Yellow 145 using a dye degrading bacterium. Sequencing analysis reveals it to be Klebsiella pneumoniae MW815592. This strain completely decolorized artificial effluent (200 mg/L) after 42 h at pH 9 and 46 °C. The decolorization rate increased in the presence of glucose and yeast extract (2 g). In addition, our finding revealed that the decolorization is due to biodegradation rather than adsorption on the bacterial surface.
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Affiliation(s)
- Rajaa Sennaj
- Agrofood and Health Laboratory, Faculty of Science and Technology, Hassan First University, PO Box 577, Settat 26000, Morocco
| | - Sanaâ Lemriss
- Laboratory of Research and Medical Analysis of Gendarmerie Royale, Department of Biosafety PCL3, Rabat, Morocco
| | - Amal Souiri
- Laboratory of Research and Medical Analysis of Gendarmerie Royale, Department of Biosafety PCL3, Rabat, Morocco
| | - Saâd E L Kabbaj
- Laboratory of Research and Medical Analysis of Gendarmerie Royale, Department of Biosafety PCL3, Rabat, Morocco
| | - Abdelbasset Chafik
- Université Cadi Ayyad, Ecole Supérieure de Technologie d'El Kelâa des Sraghna, Route de Béni Mellal Km 8 BP 104, El Kelâa des Sraghna, Morocco
| | - Abdel Khalid Essamadi
- Laboratory of Biochemistry, Neurosciences, Natural Resources and Environment, Faculty of Sciences and Technologies, Hassan First University of Settat, Settat, PObox 577 Morocco
| | - Taoufiq Benali
- Environment and Health Team, Polydisciplinary Faculty of Safi, Cadi Ayyad University, Sidi Bouzid, B.P. 4162, Safi, Morocco.
| | | | - Khadija Dari
- Agrofood and Health Laboratory, Faculty of Science and Technology, Hassan First University, PO Box 577, Settat 26000, Morocco
| | - Hinde Aassila
- Agrofood and Health Laboratory, Faculty of Science and Technology, Hassan First University, PO Box 577, Settat 26000, Morocco
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Barbeyron T, Thiébaud M, Le Duff N, Martin M, Corre E, Tanguy G, Vandenbol M, Thomas F. Zobellia roscoffensis sp. nov. and Zobellia nedashkovskayae sp. nov., two flavobacteria from the epiphytic microbiota of the brown alga Ascophyllum nodosum, and emended description of the genus Zobellia. Int J Syst Evol Microbiol 2021; 71. [PMID: 34346862 DOI: 10.1099/ijsem.0.004913] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Four marine bacterial strains were isolated from a thallus of the brown alga Ascophyllum nodosum collected in Roscoff, France. Cells were Gram-stain-negative, strictly aerobic, non-flagellated, gliding, rod-shaped and grew optimally at 25-30 °C, at pH 7-8 and with 2-4 % NaCl. Phylogenetic analyses of their 16S rRNA gene sequences showed that the bacteria were affiliated to the genus Zobellia (family Flavobacteriaceae, phylum Bacteroidetes). The four strains exhibited 97.8-100 % 16S rRNA gene sequence similarity values among themselves, 97.9-99.1 % to the type strains of Zobellia amurskyensis KMM 3526T and Zobellia laminariae KMM 3676T, and less than 99 % to other species of the genus Zobellia. The DNA G+C content of the four strains ranged from 36.7 to 37.7 mol%. Average nucleotide identity and digital DNA-DNA hybridization calculations between the new strains and other members of the genus Zobellia resulted in values of 76.4-88.9 % and below 38.5 %, respectively. Phenotypic, phylogenetic and genomic analyses showed that the four strains are distinct from species of the genus Zobellia with validly published names. They represent two novel species of the genus Zobellia, for which the names Zobellia roscoffensis sp. nov. and Zobellia nedashkovskayae sp. nov. are proposed with Asnod1-F08T (RCC6906T=KMM 6823T=CIP 111902T) and Asnod2-B07-BT (RCC6908T=KMM 6825T=CIP 111904T), respectively, as the type strains.
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Affiliation(s)
- Tristan Barbeyron
- CNRS, Sorbonne Université, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, 29680 Roscoff, Brittany, France
| | - Manon Thiébaud
- CNRS, Sorbonne Université, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, 29680 Roscoff, Brittany, France
| | - Nolwen Le Duff
- CNRS, Sorbonne Université, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, 29680 Roscoff, Brittany, France
| | - Marjolaine Martin
- University of Liège, Gembloux Agro-Bio Tech, Microbiology and Genomic Laboratory, TERRA building, avenue de la Faculté 2b, 5030 Gembloux, Belgium
| | - Erwan Corre
- CNRS, Sorbonne Université, FR2424, ABiMS, Station Biologique de Roscoff, 29680, Roscoff, Brittany, France
| | - Gwenn Tanguy
- CNRS, Sorbonne Université, FR2424, Genomer, Station Biologique de Roscoff, 29680 Roscoff, Brittany, France
| | - Micheline Vandenbol
- University of Liège, Gembloux Agro-Bio Tech, Microbiology and Genomic Laboratory, TERRA building, avenue de la Faculté 2b, 5030 Gembloux, Belgium
| | - François Thomas
- CNRS, Sorbonne Université, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, 29680 Roscoff, Brittany, France
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Nazipi S, Vangkilde-Pedersen SG, Busck MM, Lund DK, Marshall IPG, Bilde T, Lund MB, Schramm A. An antimicrobial Staphylococcus sciuri with broad temperature and salt spectrum isolated from the surface of the African social spider, Stegodyphus dumicola. Antonie Van Leeuwenhoek 2021; 114:325-35. [PMID: 33543432 DOI: 10.1007/s10482-021-01526-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 01/22/2021] [Indexed: 10/22/2022]
Abstract
Some social arthropods engage in mutualistic symbiosis with antimicrobial compound-producing microorganisms that provide protection against pathogens. Social spiders live in communal nests and contain specific endosymbionts with unknown function. Bacteria are also found on the spiders' surface, including prevalent staphylococci, which may have protective potential. Here we present the genomic and phenotypic characterization of strain i1, isolated from the surface of the social spider Stegodyphus dumicola. Phylogenomic analysis identified i1 as novel strain of Staphylococcus sciuri within subgroup 2 of three newly defined genomic subgroups. Further phenotypic investigations showed that S. sciuri i1 is an extremophile that can grow at a broad range of temperatures (4 °C-45 °C), high salt concentrations (up to 27%), and has antimicrobial activity against closely related species. We identified a lactococcin 972-like bacteriocin gene cluster, likely responsible for the antimicrobial activity, and found it conserved in two of the three subgroups of S. sciuri. These features indicate that S. sciuri i1, though not a specific symbiont, is well-adapted to survive on the surface of social spiders and may gain a competitive advantage by inhibiting closely related species.
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Busck MM, Settepani V, Bechsgaard J, Lund MB, Bilde T, Schramm A. Microbiomes and Specific Symbionts of Social Spiders: Compositional Patterns in Host Species, Populations, and Nests. Front Microbiol 2020; 11:1845. [PMID: 32849442 PMCID: PMC7412444 DOI: 10.3389/fmicb.2020.01845] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [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: 03/06/2020] [Accepted: 07/14/2020] [Indexed: 12/18/2022] Open
Abstract
Social spiders have remarkably low species-wide genetic diversities, potentially increasing the relative importance of microbial symbionts for host fitness. Here we explore the bacterial microbiomes of three species of social Stegodyphus (S. dumicola, S. mimosarum, and S. sarasinorum), within and between populations, using 16S rRNA gene amplicon sequencing. The microbiomes of the three spider species were distinct but shared similarities in membership and structure. This included low overall diversity (Shannon index 0.5–1.7), strong dominance of single symbionts in individual spiders (McNaughton’s dominance index 0.68–0.93), and a core microbiome (>50% prevalence) consisting of 5–7 specific symbionts. The most abundant and prevalent symbionts were classified as Chlamydiales, Borrelia, and Mycoplasma, all representing novel, presumably Stegodyphus-specific lineages. Borrelia- and Mycoplasma-like symbionts were localized by fluorescence in situ hybridization (FISH) in the spider midgut. The microbiomes of individual spiders were highly similar within nests but often very different between nests from the same population, with only the microbiome of S. sarasinorum consistently reflecting host population structure. The weak population pattern in microbiome composition renders microbiome-facilitated local adaptation unlikely. However, the retention of specific symbionts across populations and species may indicate a recurrent acquisition from environmental vectors or an essential symbiotic contribution to spider phenotype.
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Affiliation(s)
- Mette Marie Busck
- Section for Microbiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Virginia Settepani
- Section for Genetics, Ecology and Evolution, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Jesper Bechsgaard
- Section for Genetics, Ecology and Evolution, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Marie Braad Lund
- Section for Microbiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Trine Bilde
- Section for Genetics, Ecology and Evolution, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Andreas Schramm
- Section for Microbiology, Department of Biology, Aarhus University, Aarhus, Denmark
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Hobley L, Summers JK, Till R, Milner DS, Atterbury RJ, Stroud A, Capeness MJ, Gray S, Leidenroth A, Lambert C, Connerton I, Twycross J, Baker M, Tyson J, Kreft JU, Sockett RE. Dual Predation by Bacteriophage and Bdellovibrio bacteriovorus Can Eradicate Escherichia coli Prey in Situations where Single Predation Cannot. J Bacteriol 2020; 202:e00629-19. [PMID: 31907203 PMCID: PMC7043672 DOI: 10.1128/jb.00629-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 12/17/2019] [Indexed: 01/05/2023] Open
Abstract
Bacteria are preyed upon by diverse microbial predators, including bacteriophage and predatory bacteria, such as Bdellovibrio bacteriovorus While bacteriophage are used as antimicrobial therapies in Eastern Europe and are being applied for compassionate use in the United States, predatory bacteria are only just beginning to reveal their potential therapeutic uses. However, predation by either predator type can falter due to different adaptations arising in the prey bacteria. When testing poultry farm wastewater for novel Bdellovibrio isolates on Escherichia coli prey lawns, individual composite plaques were isolated containing both an RTP (rosette-tailed-phage)-like-phage and a B. bacteriovorus strain and showing central prey lysis and halos of extra lysis. Combining the purified phage with a lab strain of B. bacteriovorus HD100 recapitulated haloed plaques and increased killing of the E. coli prey in liquid culture, showing an effective side-by-side action of these predators compared to their actions alone. Using approximate Bayesian computation to select the best fitting from a variety of different mathematical models demonstrated that the experimental data could be explained only by assuming the existence of three prey phenotypes: (i) sensitive to both predators, (ii) genetically resistant to phage only, and (iii) plastic resistant to B. bacteriovorus only. Although each predator reduces prey availability for the other, high phage numbers did not abolish B. bacteriovorus predation, so both predators are competent to coexist and are causing different selective pressures on the bacterial surface while, in tandem, controlling prey bacterial numbers efficiently. This suggests that combinatorial predator therapy could overcome problems of phage resistance.IMPORTANCE With increasing levels of antibiotic resistance, the development of alternative antibacterial therapies is urgently needed. Two potential alternatives are bacteriophage and predatory bacteria. Bacteriophage therapy has been used, but prey/host specificity and the rapid acquisition of bacterial resistance to bacteriophage are practical considerations. Predatory bacteria are of interest due to their broad Gram-negative bacterial prey range and the lack of simple resistance mechanisms. Here, a bacteriophage and a strain of Bdellovibrio bacteriovorus, preyed side by side on a population of E. coli, causing a significantly greater decrease in prey numbers than either alone. Such combinatorial predator therapy may have greater potential than individual predators since prey surface changes selected for by each predator do not protect prey against the other predator.
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Affiliation(s)
- Laura Hobley
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - J Kimberley Summers
- Institute of Microbiology and Infection and Centre for Computational Biology and School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Rob Till
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - David S Milner
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Robert J Atterbury
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Amy Stroud
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Michael J Capeness
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Stephanie Gray
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Andreas Leidenroth
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Carey Lambert
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Ian Connerton
- School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Jamie Twycross
- School of Computer Science, University of Nottingham, Nottingham, United Kingdom
| | - Michelle Baker
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Jess Tyson
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Jan-Ulrich Kreft
- Institute of Microbiology and Infection and Centre for Computational Biology and School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - R Elizabeth Sockett
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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Barbeyron T, Zonta E, Le Panse S, Duchaud E, Michel G. Alteromonas fortis sp. nov., a non-flagellated bacterium specialized in the degradation of iota-carrageenan, and emended description of the genus Alteromonas. Int J Syst Evol Microbiol 2019; 69:2514-2521. [DOI: 10.1099/ijsem.0.003533] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Tristan Barbeyron
- 1CNRS / Sorbonne Université, UMR 8227 Integrative Biology of Marine Models (LBI2M), research group of Marine Glycobiology, Station Biologique de Roscoff (SBR), 29680 Roscoff, Brittany, France
| | - Erwann Zonta
- 1CNRS / Sorbonne Université, UMR 8227 Integrative Biology of Marine Models (LBI2M), research group of Marine Glycobiology, Station Biologique de Roscoff (SBR), 29680 Roscoff, Brittany, France
| | - Sophie Le Panse
- 2CNRS / Sorbonne Université, FR 2424 Research and training in marine biology, Merimage platform, Station Biologique de Roscoff (SBR), 29680 Roscoff, Brittany, France
| | - Eric Duchaud
- 3INRA VIM-UR0892 Molecular Immunology and Virology, research group of Infection and Immunity of Fish, Research Center of Jouy-en-Josas, F-78352 Jouy-en-Josas, Ile-de-France, France
| | - Gurvan Michel
- 1CNRS / Sorbonne Université, UMR 8227 Integrative Biology of Marine Models (LBI2M), research group of Marine Glycobiology, Station Biologique de Roscoff (SBR), 29680 Roscoff, Brittany, France
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Li Y, Yu T, Kang D, Shan X, Zheng P, Hu Z, Ding A, Wang R, Zhang M. Sources of anammox granular sludge and their sustainability in treating low-strength wastewater. Chemosphere 2019; 226:229-237. [PMID: 30928715 DOI: 10.1016/j.chemosphere.2019.03.049] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 02/28/2019] [Accepted: 03/10/2019] [Indexed: 06/09/2023]
Abstract
Anaerobic ammonium oxidation (anammox) has been widely applied in the treatment of high-strength nitrogen wastewaters. However, few engineering practices were reported to treat low-strength nitrogen wastewaters. In this study, three types of anammox granular sludge (GS) were separately collected from the expanded granular sludge bed (EGSB) reactors treating nitrogen wastewaters at high (H-), moderate (M-) and low (L-) nitrogen loading rates (NLRs), and employed for the treatment of low-strength nitrogen wastewater in sequencing batch advanced nitrogen removal (ANR) systems. The ANR system with M-GS (namely M-ANR system) was most useful. At the initial biomass concentration of 2.43 g-VSS·L-1, cycle length of 8 h and influent total nitrogen (TN) concentration of less than 15 mg·L-1, the performance data were as follows: effluent TN of less than 1 mg·L-1, TN removal efficiency of more than 92.8%, the nitrogen removal rate (NRR) of 0.039 kg-N·m-3·d-1. The efficient performance lasted as long as 46 cycles, indicating the sustainability of the M-ANR system. The advanced microscopic analysis and metagenomic analysis were applied to reveal the successful but non-permanent treatment by the M-ANR system. The long-time lag between biomass decay and sludge activity decay provided a window period for the good performance of M-ANR system. However, the weak support of oligotrophic habitat for anaerobic ammonium oxidizing bacteria community was doomed to the degradation of anammox GS, resulting in gradual loss of their activities. A periodic addition of fresh M-GS or a periodic rejuvenation cultivation in the eutrophic habitat is necessary to achieve a permanent performance.
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Affiliation(s)
- Yiyu Li
- Department of Environmental Engineering, Zhejiang University, Hangzhou, China
| | - Tao Yu
- Department of Environmental Engineering, Zhejiang University, Hangzhou, China
| | - Da Kang
- Department of Environmental Engineering, Zhejiang University, Hangzhou, China
| | - Xiaoyu Shan
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, USA
| | - Ping Zheng
- Department of Environmental Engineering, Zhejiang University, Hangzhou, China.
| | - Zhiqiang Hu
- Department of Civil and Environmental Engineering, University of Missouri, Columbia, USA
| | - Aqiang Ding
- Department of Environmental Engineering, Chongqing University, Chongqing, China
| | - Ru Wang
- Department of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, China
| | - Meng Zhang
- Department of Environmental Engineering, Zhejiang University, Hangzhou, China
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Yasuhara T, Yuuki T, Kagami N. Novel Quantitative Method for Detection ofPectinatusUsing rRNA Targeted Fluorescent Probes. Journal of the American Society of Brewing Chemists 2018. [DOI: 10.1094/asbcj-59-0117] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Takaomi Yasuhara
- Brewing Research and Development Laboratory, Asahi Breweries, Ltd., 1-21, Midori, 1-Chome, Moriya-machi, Kitasoma-gun, Ibaraki, 302-0106 Japan
| | - Toshifumi Yuuki
- Brewing Research and Development Laboratory, Asahi Breweries, Ltd., 1-21, Midori, 1-Chome, Moriya-machi, Kitasoma-gun, Ibaraki, 302-0106 Japan
| | - Noboru Kagami
- Brewing Research and Development Laboratory, Asahi Breweries, Ltd., 1-21, Midori, 1-Chome, Moriya-machi, Kitasoma-gun, Ibaraki, 302-0106 Japan
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Paz LC, Schramm A, Lund MB. Biparental transmission of Verminephrobacter symbionts in the earthworm Aporrectodea tuberculata (Lumbricidae). FEMS Microbiol Ecol 2017; 93:3045886. [DOI: 10.1093/femsec/fix025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 02/21/2017] [Indexed: 11/13/2022] Open
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Muthukrishnan T, Govender A, Dobretsov S, Abed R. Evaluating the Reliability of Counting Bacteria Using Epifluorescence Microscopy. JMSE 2017; 5:4. [DOI: 10.3390/jmse5010004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Sinha RK, Krishnan KP, Hatha AAM, Rahiman M, Thresyamma DD, Kerkar S. Diversity of retrievable heterotrophic bacteria in Kongsfjorden, an Arctic fjord. Braz J Microbiol 2016; 48:51-61. [PMID: 28029589 PMCID: PMC5221401 DOI: 10.1016/j.bjm.2016.09.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [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: 07/10/2015] [Accepted: 12/22/2015] [Indexed: 11/19/2022] Open
Abstract
The diversity and abundance of retrievable pelagic heterotrophic bacteria in Kongsfjorden, an Arctic fjord, was studied during the summer of 2011 (June, August, and September). Retrievable bacterial load ranged from 103 to 107 CFU L−1 in June, while it was 104–106 CFU L−1 in August and September. Based on 16S rRNA gene sequence similarities, a higher number of phylotypes was observed during August (22 phylotypes) compared to that during June (6 phylotypes) and September (12 phylotypes). The groups were classified into four phyla: Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes. Bacteroidetes was represented only by a single member Leewenhoekiella aequorea during the three months and was dominant (40%) in June. However, this dominance changed in August to a well-known phytopathogenic species Rhodococcus fascians (32%), which could be a result of decrease in the phytoplankton biomass following the secondary bloom. It is the first report of Halomonas titanicae isolation from the Arctic waters. It showed an increase in its abundance with the intrusion of Atlantic water into Kongsfjorden. Increased abundance of Psychrobacter species in the late summer months coincided with the presence of cooler waters. Thus, the composition and function of heterotrophic bacterial community was fundamentally different in different months. This could be linked to the changes in the water masses and/or phytoplankton bloom dynamics occurring in Arctic summer.
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Affiliation(s)
- Rupesh Kumar Sinha
- National Centre for Antarctic and Ocean Research, ESSO-NCAOR, Head land Sada, Vasco-da-Gama, Goa, India.
| | | | | | - Mujeeb Rahiman
- Cochin University of Science and Technology, Microbiology and Biochemistry, Department of Marine Biology, Cochin, Kerala, India
| | - Divya David Thresyamma
- National Centre for Antarctic and Ocean Research, ESSO-NCAOR, Head land Sada, Vasco-da-Gama, Goa, India
| | - Savita Kerkar
- Goa University, Department of Biotechnology, Taleigao Plateau, Goa, India
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Sinha RK, Krishnan KP, Kerkar S, Divya David T. Spatio-Temporal Monitoring and Ecological Significance of Retrievable Pelagic Heterotrophic Bacteria in Kongsfjorden, an Arctic Fjord. Indian J Microbiol 2017; 57:116-20. [PMID: 28148988 DOI: 10.1007/s12088-016-0621-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 09/19/2016] [Indexed: 10/21/2022] Open
Abstract
Kongsfjorden is a glacial fjord in the Arctic that is influenced by both Atlantic and Arctic water masses. In the present report retrievable heterotrophic bacteria isolated from two distinct zones (outer and inner fjord) of Kongsfjorden was studied during summer to fall of 2012. 16S rRNA gene sequences of the retrievable heterotrophic bacteria corresponded to γ-proteobacteria (13 phylotypes), α-proteobacteria (3 phylotypes), Bacteroidetes (4 phylotypes) and Actinobacteria (2 phylotypes). The heterotrophic bacterial community structure was fundamentally different in different months which could be linked to changes in the water masses and/or phytoplankton bloom dynamics. It is hypothesized that monitoring the retrievable heterotrophic bacterial assemblage in the fjord would give valuable insights into the complex ecological role they play under extreme and dynamic conditions.
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Schreiber L, Kjeldsen KU, Funch P, Jensen J, Obst M, López-Legentil S, Schramm A. Endozoicomonas Are Specific, Facultative Symbionts of Sea Squirts. Front Microbiol 2016; 7:1042. [PMID: 27462299 PMCID: PMC4940369 DOI: 10.3389/fmicb.2016.01042] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [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: 04/26/2016] [Accepted: 06/21/2016] [Indexed: 11/13/2022] Open
Abstract
Ascidians are marine filter feeders and harbor diverse microbiota that can exhibit a high degree of host-specificity. Pharyngeal samples of Scandinavian and Mediterranean ascidians were screened for consistently associated bacteria by culture-dependent and -independent approaches. Representatives of the Endozoicomonas (Gammaproteobacteria, Hahellaceae) clade were detected in the ascidian species Ascidiella aspersa, Ascidiella scabra, Botryllus schlosseri, Ciona intestinalis, Styela clava, and multiple Ascidia/Ascidiella spp. In total, Endozoicomonas was detected in more than half of all specimens screened, and in 25-100% of the specimens for each species. The retrieved Endozoicomonas 16S rRNA gene sequences formed an ascidian-specific subclade, whose members were detected by fluorescence in situ hybridization (FISH) as extracellular microcolonies in the pharynx. Two strains of the ascidian-specific Endozoicomonas subclade were isolated in pure culture and characterized. Both strains are chemoorganoheterotrophs and grow on mucin (a mucus glycoprotein). The strains tested negative for cytotoxic or antibacterial activity. Based on these observations, we propose ascidian-associated Endozoicomonas to be commensals, living off the mucus continuously secreted into the pharynx. Members of the ascidian-specific Endozoicomonas subclade were also detected in seawater from the Scandinavian sampling site, which suggests acquisition of the symbionts by horizontal transmission. The combined results indicate a host-specific, yet facultative symbiosis between ascidians and Endozoicomonas.
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Affiliation(s)
- Lars Schreiber
- Department of Bioscience, Center for Geomicrobiology and Section for Microbiology, Aarhus University Aarhus, Denmark
| | - Kasper U Kjeldsen
- Department of Bioscience, Center for Geomicrobiology and Section for Microbiology, Aarhus University Aarhus, Denmark
| | - Peter Funch
- Section of Genetics, Ecology and Evolution, Department of Bioscience, Aarhus University Aarhus, Denmark
| | - Jeppe Jensen
- Department of Bioscience, Center for Geomicrobiology and Section for Microbiology, Aarhus University Aarhus, Denmark
| | - Matthias Obst
- Department of Marine Sciences, University of Gothenburg Gothenburg, Sweden
| | - Susanna López-Legentil
- Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington Wilmington NC, USA
| | - Andreas Schramm
- Department of Bioscience, Center for Geomicrobiology and Section for Microbiology, Aarhus University Aarhus, Denmark
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Tapia-Paniagua ST, Vidal S, Lobo C, García de la Banda I, Esteban MA, Balebona MC, Moriñigo MA. Dietary administration of the probiotic SpPdp11: Effects on the intestinal microbiota and immune-related gene expression of farmed Solea senegalensis treated with oxytetracycline. Fish Shellfish Immunol 2015; 46:449-458. [PMID: 26190256 DOI: 10.1016/j.fsi.2015.07.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [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: 04/01/2015] [Revised: 07/08/2015] [Accepted: 07/14/2015] [Indexed: 06/04/2023]
Abstract
Few antimicrobials are currently authorised in the aquaculture industry to treat infectious diseases. Among them, oxytetracycline (OTC) is one of the first-choice drugs for nearly all bacterial diseases. The objective of this study was to evaluate the effect of the dietary administration of OTC both alone and jointly with the probiotic Shewanella putrefaciens Pdp11 (SpPdp11) on the intestinal microbiota and hepatic expression of genes related to immunity in Senegalese sole (Solea senegalensis) juveniles. The results demonstrated that the richness and diversity of the intestinal microbiota of fish treated with OTC decreased compared with those of the control group but that these effects were lessened by the simultaneous administration of SpPdp11. In addition, specimens that received OTC and SpPdp11 jointly showed a decreased intensity of the Denaturing Gradient Gel Electrophoresis (DGGE) bands related to Vibrio genus and the presence of DGGE bands related to Lactobacillus and Shewanella genera. The relationship among the intestinal microbiota of fish fed with control and OTC diets and the expression of the NADPH oxidase and CASPASE-6 genes was demonstrated by a Principal Components Analysis (PCA) carried out in this study. In contrast, a close relationship between the transcription of genes, such as NKEF, IGF-β, HSP70 and GP96, and the DGGE bands of fish treated jointly with OTC and SpPdp11 was observed in the PCA study. In summary, the results obtained in this study demonstrate that the administration of OTC results in the up-regulation of genes related to apoptosis but that the joint administration of OTC and S. putrefaciens Pdp11 increases the transcription of genes related to antiapoptotic effects and oxidative stress regulation. Further, a clear relationship between these changes and those detected in the intestinal microbiota is established.
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Affiliation(s)
- S T Tapia-Paniagua
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - S Vidal
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - C Lobo
- Spanish Institute of Oceanography, Oceanographic Center of Santander, 39080 Santander, Spain
| | - I García de la Banda
- Spanish Institute of Oceanography, Oceanographic Center of Santander, 39080 Santander, Spain
| | - M A Esteban
- Innate Immune System Group, Department of Cell Biology and Histology, Faculty of Biology, Campus Regional de Excelencia Internacional "Campus Mare Nostrum", University of Murcia, 30100 Murcia, Spain
| | - M C Balebona
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - M A Moriñigo
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain.
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Krishnan KP, Sinha RK, Nair S, Noronha SB, Chacko R, Anilkumar N. Carbon demand, utilization, and metabolic diversity of bacterioplankton in the frontal regimes of the Indian sector of the Southern Ocean. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-014-0948-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Aguinaga Casañas MA, Rangkasenee N, Krattenmacher N, Thaller G, Metges CC, Kuhla B. Methyl-coenzyme M reductase A as an indicator to estimate methane production from dairy cows. J Dairy Sci 2015; 98:4074-83. [PMID: 25841964 DOI: 10.3168/jds.2015-9310] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [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: 01/05/2015] [Accepted: 02/24/2015] [Indexed: 11/19/2022]
Abstract
The evaluation of greenhouse gas mitigation strategies requires the quantitative assessment of individual methane production. Because methane measurement in respiration chambers is highly accurate, but also comprises various disadvantages such as limited capacity and high costs, the establishment of an indicator for estimating methane production of individual ruminants would provide an alternative to direct methane measurement. Methyl-coenzyme M reductase is involved in methanogenesis and the subunit α of methyl-coenzyme M reductase is encoded by the mcrA gene of rumen archaea. We therefore examined the relationship between methane emissions of Holstein dairy cows measured in respiration chambers with 2 different diets (high- and medium-concentrate diet) and the mcrA DNA and mcrA cDNA abundance determined from corresponding rumen fluid samples. Whole-body methane production per kilogram of dry matter intake and mcrA DNA normalized to the abundance of the rrs gene coding for 16S rRNA correlated significantly when using qmcrA primers. Use of qmcrA primers also revealed linear correlation between mcrA DNA copy number and methane yield. Regression analyses based on normalized mcrA cDNA abundances revealed no significant linear correlation with methane production per kilogram of dry matter intake. Furthermore, the correlations between normalized mcrA DNA abundance and the rumen fluid concentration of acetic and isobutyric acid were positive, whereas the correlations with propionic and lactic acid were negative. These data suggest that the mcrA DNA approach based on qmcrA primers could potentially be a molecular proxy for methane yield after further refinement.
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Affiliation(s)
- M A Aguinaga Casañas
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - N Rangkasenee
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - N Krattenmacher
- Institute of Animal Breeding and Husbandry, Christian-Albrechts-University, Hermann-Rodewald-Straße 6, D-24118 Kiel, Germany
| | - G Thaller
- Institute of Animal Breeding and Husbandry, Christian-Albrechts-University, Hermann-Rodewald-Straße 6, D-24118 Kiel, Germany
| | - C C Metges
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - B Kuhla
- Institute of Nutritional Physiology "Oskar Kellner," Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
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Tapia-Paniagua S, Lobo C, Moreno-Ventas X, de la Banda IG, Moriñigo MA, Balebona MC. Probiotic supplementation influences the diversity of the intestinal microbiota during early stages of farmed senegalese sole (Solea Senegalensis, Kaup 1858). Mar Biotechnol (NY) 2014; 16:716-728. [PMID: 25103323 DOI: 10.1007/s10126-014-9588-6] [Citation(s) in RCA: 16] [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] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 07/06/2014] [Indexed: 06/03/2023]
Abstract
Ingestion of bacteria at early stages results in establishment of a primary intestinal microbiota which likely undergoes several stages along fish life. The role of this intestinal microbiota regulating body functions is crucial for larval development. Probiotics have been proved to modulate this microbiota and exert antagonistic effects against fish pathogens. In the present study, we aimed to determine bacterial diversity along different developmental stages of farmed Senegalese sole (Solea senegalensis) after feeding probiotic (Shewanella putrefaciens Pdp11) supplemented diet for a short period (10-30 days after hatching, DAH). Intestinal lumen contents of sole larvae fed control and probiotic diets were collected at 23, 56, 87, and 119 DAH and DNA was amplified using 16S rDNA bacterial domain-specific primers. Amplicons obtained were separated by denaturing gradient gel electrophoresis (DGGE), cloned, and resulting sequences compared to sequences in GenBank. Results suggest that Shewanella putrefaciens Pdp11 induces a modulation of the dominant bacterial taxa of the intestinal microbiota from 23 DAH. DGGE patterns of larvae fed the probiotic diet showed a core of bands related to Lactobacillus helveticus, Pseudomonas acephalitica, Vibrio parahaemolyticus, and Shewanella genus, together with increased Vibrio genus presence. In addition, decreased number of clones related to Photobacterium damselae subsp piscicida at 23 and 56 DAH was observed in probiotic-fed larvae. A band corresponding to Shewanella putrefaciens Pdp11 was sequenced as predominant from 23 to 119 DAH samples, confirming the colonization by the probiotics. Microbiota modulation obtained via probiotics addition emerges as an effective tool to improve Solea senegalensis larviculture.
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Affiliation(s)
- Silvana Tapia-Paniagua
- Departamento de Microbiología, Universidad de Málaga, Campus de Teatinos s/n, 29071, Málaga, Spain
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Tapia-Paniagua ST, Vidal S, Lobo C, Prieto-Álamo MJ, Jurado J, Cordero H, Cerezuela R, García de la Banda I, Esteban MA, Balebona MC, Moriñigo MA. The treatment with the probiotic Shewanella putrefaciens Pdp11 of specimens of Solea senegalensis exposed to high stocking densities to enhance their resistance to disease. Fish Shellfish Immunol 2014; 41:209-221. [PMID: 25149590 DOI: 10.1016/j.fsi.2014.08.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [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: 05/07/2014] [Revised: 07/30/2014] [Accepted: 08/07/2014] [Indexed: 06/03/2023]
Abstract
Aquaculture industry exposes fish to acute stress events, such as high stocking density, and a link between stress and higher susceptibility to diseases has been concluded. Several studies have demonstrated increased stress tolerance of fish treated with probiotics, but the mechanisms involved have not been elucidated. Shewanella putrefaciens Pdp11 is a strain isolated from healthy gilthead seabream (Sparus aurata L.) and it is considered as probiotics. The aim of this study was to evaluate the effect of the dietary administration of this probiotics on the stress tolerance of Solea senegalensis specimens farmed under high stocking density (PHD) compared to a group fed a commercial diet and farmed under the same conditions (CHD). In addition, during the experiment, a natural infectious outbreak due to Vibrio species affected fish farmed under crowding conditions. Changes in the microbiota and histology of intestine and in the transcription of immune response genes were evaluated at 19 and 30 days of the experiment. Mortality was observed after 9 days of the beginning of the experiment in CHD and PHD groups, it being higher in the CHD group. Fish farmed under crowding stress showed reduced expression of genes at 19 day probiotic feeding. On the contrary, a significant increase in immune related gene expression was detected in CHD fish at 30 day, whereas the gene expression in fish from PHD group was very similar to that showed in specimens fed and farmed with the conventional conditions. In addition, the dietary administration of S. putrefaciens Pdp11 produced an important modulation of the intestinal microbiota, which was significantly correlated with the high number of goblet cells detected in fish fed the probiotic diet.
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Affiliation(s)
- S T Tapia-Paniagua
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - S Vidal
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - C Lobo
- Instituto Español de Oceanografía, Centro Oceanográfico de Santander, 39080 Santander, Spain
| | - M J Prieto-Álamo
- Universidad de Córdoba, Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Ctra. Madrid, Km. 396, 14071 Córdoba, Spain
| | - J Jurado
- Universidad de Córdoba, Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Ctra. Madrid, Km. 396, 14071 Córdoba, Spain
| | - H Cordero
- Universidad de Murcia, Departamento de Biología Celular e Histología, Campus de Espinardo s/n, 30100 Murcia, Spain
| | - R Cerezuela
- Universidad de Murcia, Departamento de Biología Celular e Histología, Campus de Espinardo s/n, 30100 Murcia, Spain
| | - I García de la Banda
- Instituto Español de Oceanografía, Centro Oceanográfico de Santander, 39080 Santander, Spain
| | - M A Esteban
- Universidad de Murcia, Departamento de Biología Celular e Histología, Campus de Espinardo s/n, 30100 Murcia, Spain
| | - M C Balebona
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain
| | - M A Moriñigo
- Universidad de Málaga, Departamento de Microbiología, Campus de Teatinos s/n, 29071 Málaga, Spain.
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Koch H, Galushko A, Albertsen M, Schintlmeister A, Gruber-Dorninger C, Lücker S, Pelletier E, Le Paslier D, Spieck E, Richter A, Nielsen PH, Wagner M, Daims H. Growth of nitrite-oxidizing bacteria by aerobic hydrogen oxidation. Science 2014; 345:1052-4. [PMID: 25170152 DOI: 10.1126/science.1256985] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The bacterial oxidation of nitrite to nitrate is a key process of the biogeochemical nitrogen cycle. Nitrite-oxidizing bacteria are considered a highly specialized functional group, which depends on the supply of nitrite from other microorganisms and whose distribution strictly correlates with nitrification in the environment and in wastewater treatment plants. On the basis of genomics, physiological experiments, and single-cell analyses, we show that Nitrospira moscoviensis, which represents a widely distributed lineage of nitrite-oxidizing bacteria, has the genetic inventory to utilize hydrogen (H2) as an alternative energy source for aerobic respiration and grows on H2 without nitrite. CO2 fixation occurred with H2 as the sole electron donor. Our results demonstrate a chemolithoautotrophic lifestyle of nitrite-oxidizing bacteria outside the nitrogen cycle, suggesting greater ecological flexibility than previously assumed.
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Affiliation(s)
- Hanna Koch
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria
| | - Alexander Galushko
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria
| | - Mads Albertsen
- Center for Microbial Communities, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, 9000 Aalborg, Denmark
| | - Arno Schintlmeister
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria. Large Instrument Facility for Advanced Isotope Research, University of Vienna, 1090 Vienna, Austria
| | - Christiane Gruber-Dorninger
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria
| | - Sebastian Lücker
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria
| | - Eric Pelletier
- Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de génomique, Genoscope, 91057 Evry, France. Centre National de la Recherche Scientifique, UMR8030, 91057 Evry, France. Université d'Evry Val d'Essonne, 91057 Evry, France
| | - Denis Le Paslier
- Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de génomique, Genoscope, 91057 Evry, France. Centre National de la Recherche Scientifique, UMR8030, 91057 Evry, France. Université d'Evry Val d'Essonne, 91057 Evry, France
| | - Eva Spieck
- Biozentrum Klein Flottbek, Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany
| | - Andreas Richter
- Department of Microbiology and Ecosystem Science, Division of Terrestrial Ecosystem Research, University of Vienna, 1090 Vienna, Austria
| | - Per H Nielsen
- Center for Microbial Communities, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, 9000 Aalborg, Denmark
| | - Michael Wagner
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria
| | - Holger Daims
- Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria.
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Gruber-Dorninger C, Pester M, Kitzinger K, Savio DF, Loy A, Rattei T, Wagner M, Daims H. Functionally relevant diversity of closely related Nitrospira in activated sludge. ISME J 2015; 9:643-55. [PMID: 25148481 DOI: 10.1038/ismej.2014.156] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 06/28/2014] [Accepted: 07/18/2014] [Indexed: 11/08/2022]
Abstract
Nitrospira are chemolithoautotrophic nitrite-oxidizing bacteria that catalyze the second step of nitrification in most oxic habitats and are important for excess nitrogen removal from sewage in wastewater treatment plants (WWTPs). To date, little is known about their diversity and ecological niche partitioning within complex communities. In this study, the fine-scale community structure and function of Nitrospira was analyzed in two full-scale WWTPs as model ecosystems. In Nitrospira-specific 16S rRNA clone libraries retrieved from each plant, closely related phylogenetic clusters (16S rRNA identities between clusters ranged from 95.8% to 99.6%) within Nitrospira lineages I and II were found. Newly designed probes for fluorescence in situ hybridization (FISH) allowed the specific detection of several of these clusters, whose coexistence in the WWTPs was shown for prolonged periods of several years. In situ ecophysiological analyses based on FISH, relative abundance and spatial arrangement quantification, as well as microautoradiography revealed functional differences of these Nitrospira clusters regarding the preferred nitrite concentration, the utilization of formate as substrate and the spatial coaggregation with ammonia-oxidizing bacteria as symbiotic partners. Amplicon pyrosequencing of the nxrB gene, which encodes subunit beta of nitrite oxidoreductase of Nitrospira, revealed in one of the WWTPs as many as 121 species-level nxrB operational taxonomic units with highly uneven relative abundances in the amplicon library. These results show a previously unrecognized high diversity of Nitrospira in engineered systems, which is at least partially linked to niche differentiation and may have important implications for process stability.
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Xia JH, Lin G, Fu GH, Wan ZY, Lee M, Wang L, Liu XJ, Yue GH. The intestinal microbiome of fish under starvation. BMC Genomics 2014; 15:266. [PMID: 24708260 PMCID: PMC4234480 DOI: 10.1186/1471-2164-15-266] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [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: 07/27/2013] [Accepted: 03/31/2014] [Indexed: 02/08/2023] Open
Abstract
Background Starvation not only affects the nutritional and health status of the animals, but also the microbial composition in the host’s intestine. Next-generation sequencing provides a unique opportunity to explore gut microbial communities and their interactions with hosts. However, studies on gut microbiomes have been conducted predominantly in humans and land animals. Not much is known on gut microbiomes of aquatic animals and their changes under changing environmental conditions. To address this shortcoming, we determined the microbial gene catalogue, and investigated changes in the microbial composition and host-microbe interactions in the intestine of Asian seabass in response to starvation. Results We found 33 phyla, 66 classes, 130 orders and 278 families in the intestinal microbiome. Proteobacteria (48.8%), Firmicutes (15.3%) and Bacteroidetes (8.2%) were the three most abundant bacteria taxa. Comparative analyses of the microbiome revealed shifts in bacteria communities, with dramatic enrichment of Bacteroidetes, but significant depletion of Betaproteobacteria in starved intestines. In addition, significant differences in clusters of orthologous groups (COG) functional categories and orthologous groups were observed. Genes related to antibiotic activity in the microbiome were significantly enriched in response to starvation, and host genes related to the immune response were generally up-regulated. Conclusions This study provides the first insights into the fish intestinal microbiome and its changes under starvation. Further detailed study on interactions between intestinal microbiomes and hosts under dynamic conditions will shed new light on how the hosts and microbes respond to the changing environment.
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Affiliation(s)
| | | | | | | | | | | | | | - Gen Hua Yue
- Molecular Population Genetics Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Republic of Singapore.
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Nielsen MB, Kjeldsen KU, Lever MA, Ingvorsen K. Survival of prokaryotes in a polluted waste dump during remediation by alkaline hydrolysis. Ecotoxicology 2014; 23:404-418. [PMID: 24532314 DOI: 10.1007/s10646-014-1205-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/27/2014] [Indexed: 06/03/2023]
Abstract
A combination of culture-dependent and culture-independent techniques was used to characterize bacterial and archaeal communities in a highly polluted waste dump and to assess the effect of remediation by alkaline hydrolysis on these communities. This waste dump (Breakwater 42), located in Denmark, contains approximately 100 different toxic compounds including large amounts of organophosphorous pesticides such as parathions. The alkaline hydrolysis (12 months at pH >12) decimated bacterial and archaeal abundances, as estimated by 16S rRNA gene-based qPCR, from 2.1 × 10(4) and 2.9 × 10(3) gene copies per gram wet soil respectively to below the detection limit of the qPCR assay. Clone libraries constructed from PCR-amplified 16S rRNA gene fragments showed a significant reduction in bacterial diversity as a result of the alkaline hydrolysis, with preferential survival of Betaproteobacteria, which increased in relative abundance from 0 to 48 %. Many of the bacterial clone sequences and the 27 isolates were related to known xenobiotic degraders. An archaeal clone library from a non-hydrolyzed sample showed the presence of three main clusters, two representing methanogens and one representing marine aerobic ammonia oxidizers. Isolation of alkalitolerant bacterial pure cultures from the hydrolyzed soil confirmed that although alkaline hydrolysis severely reduces microbial community diversity and size certain bacteria survive a prolonged alkaline hydrolysis process. Some of the isolates from the hydrolyzed soil were capable of growing at high pH (pH 10.0) in synthetic media indicating that they could become active in in situ biodegradation upon hydrolysis.
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Affiliation(s)
- Marie Bank Nielsen
- Department of Bioscience, Microbiology, Aarhus University, Ny Munkegade 116, Building 1540, 8000, Aarhus C, Denmark,
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Lee EJ, Lim KH. Semi-pilot Scaled Hybrid Process Treatment of Malodorous Waste Air: Performance of Hybrid System Composed of Biofilter Packed with Media Inoculated with Thiobacillus sp. IW and Return-sludge and Photocatalytic Reactor. Korean Chemical Engineering Research 2014. [DOI: 10.9713/kcer.2014.52.2.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Krishnan KP, Sinha RK, Rajan S. Pelagic nitrification and denitrification rates in an Arctic fjord during early spring. ANN MICROBIOL 2014; 64:365-376. [DOI: 10.1007/s13213-013-0671-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Bouali M, Zrafi I, Bakhrouf A, Chaussonnerie S, Sghir A. Bacterial structure and spatiotemporal distribution in a horizontal subsurface flow constructed wetland. Appl Microbiol Biotechnol 2014; 98:3191-203. [DOI: 10.1007/s00253-013-5341-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 10/14/2013] [Accepted: 10/17/2013] [Indexed: 10/26/2022]
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Illakkiam D, Ponraj P, Shankar M, Muthusubramanian S, Rajendhran J, Gunasekaran P. Identification and structure elucidation of a novel antifungal compound produced by Pseudomonas aeruginosa PGPR2 against Macrophomina phaseolina. Appl Biochem Biotechnol 2013; 171:2176-85. [PMID: 24037513 DOI: 10.1007/s12010-013-0469-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 08/22/2013] [Indexed: 10/26/2022]
Abstract
Pseudomonas aeruginosa PGPR2 was found to protect mungbean plants from charcoal rot disease caused by Macrophomina phaseolina. Secondary metabolites from the culture supernatant of P. aeruginosa PGPR2 were extracted with ethyl acetate and the antifungal compound was purified by preparative HPLC using reverse phase chromatography. The purified compound showed antifungal activity against M. phaseolina and other phytopathogenic fungi (Fusarium sp., Rhizoctonia sp. Alternaria sp., and Aspergillus sp.). The structure of the purified compound was determined using (1)H, (13)C, 2D NMR spectra and liquid chromatography-mass spectrometry (LC-MS). Spectral data suggest that the antifungal compound is 3,4-dihydroxy-N-methyl-4-(4-oxochroman-2-yl)butanamide, with the chemical formula C14H17NO5 and a molecular mass of 279. Though chemically synthesized chromanone derivatives have been shown to have antifungal activity, we report for the first time, the microbial production of a chromanone derivative with antifungal activity. This ability of P. aeruginosa PGPR2 makes it a suitable strain for biocontrol.
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Affiliation(s)
- Devaraj Illakkiam
- Department of Genetics, Centre for Excellence in Genomic Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625 021, India
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Hoshino T, Inagaki F. A comparative study of microbial diversity and community structure in marine sediments using poly(A) tailing and reverse transcription-PCR. Front Microbiol 2013; 4:160. [PMID: 23785366 PMCID: PMC3684792 DOI: 10.3389/fmicb.2013.00160] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [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: 03/05/2013] [Accepted: 05/31/2013] [Indexed: 01/16/2023] Open
Abstract
To obtain a better understanding of metabolically active microbial communities, we tested a molecular ecological approach using poly(A) tailing of environmental 16S rRNA, followed by full-length complementary DNA (cDNA) synthesis and sequencing to eliminate potential biases caused by mismatching of polymerase chain reaction (PCR) primer sequences. The RNA pool tested was extracted from marine sediments of the Yonaguni Knoll IV hydrothermal field in the southern Okinawa Trough. The sequences obtained using the poly(A) tailing method were compared statistically and phylogenetically with those obtained using conventional reverse transcription-PCR (RT-PCR) with published domain-specific primers. Both methods indicated that Deltaproteobacteria are predominant in sediment (>85% of the total sequence read). The poly(A) tailing method indicated that Desulfobacterales were the predominant Deltaproteobacteria, while most of the sequences in libraries constructed using RT-PCR were derived from Desulfuromonadales. This discrepancy may have been due to low coverage of Desulfobacterales by the primers used. A comparison of library diversity indices indicated that the poly(A) tailing method retrieves more phylogenetically diverse sequences from the environment. The four archaeal 16S rRNA sequences that were obtained using the poly(A) tailing method formed deeply branching lineages that were related to Candidatus "Parvarchaeum" and the ancient archaeal group. These results clearly demonstrate that poly(A) tailing followed by cDNA sequencing is a powerful and less biased molecular ecological approach for the study of metabolically active microbial communities.
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Affiliation(s)
- Tatsuhiko Hoshino
- Geomicrobiology Group, Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology Nankoku, Kochi, Japan ; Geobio-Engineering and Technology Group, Submarine Resources Research Project, Japan Agency for Marine-Earth Science and Technology Nankoku, Kochi, Japan
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Jaekel U, Musat N, Adam B, Kuypers M, Grundmann O, Musat F. Anaerobic degradation of propane and butane by sulfate-reducing bacteria enriched from marine hydrocarbon cold seeps. ISME J 2013; 7:885-95. [PMID: 23254512 PMCID: PMC3635235 DOI: 10.1038/ismej.2012.159] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [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: 01/12/2012] [Revised: 10/17/2012] [Accepted: 10/28/2012] [Indexed: 11/09/2022]
Abstract
The short-chain, non-methane hydrocarbons propane and butane can contribute significantly to the carbon and sulfur cycles in marine environments affected by oil or natural gas seepage. In the present study, we enriched and identified novel propane and butane-degrading sulfate reducers from marine oil and gas cold seeps in the Gulf of Mexico and Hydrate Ridge. The enrichment cultures obtained were able to degrade simultaneously propane and butane, but not other gaseous alkanes. They were cold-adapted, showing highest sulfate-reduction rates between 16 and 20 °C. Analysis of 16S rRNA gene libraries, followed by whole-cell hybridizations with sequence-specific oligonucleotide probes showed that each enrichment culture was dominated by a unique phylotype affiliated with the Desulfosarcina-Desulfococcus cluster within the Deltaproteobacteria. These phylotypes formed a distinct phylogenetic cluster of propane and butane degraders, including sequences from environments associated with hydrocarbon seeps. Incubations with (13)C-labeled substrates, hybridizations with sequence-specific probes and nanoSIMS analyses showed that cells of the dominant phylotypes were the first to become enriched in (13)C, demonstrating that they were directly involved in hydrocarbon degradation. Furthermore, using the nanoSIMS data, carbon assimilation rates were calculated for the dominant cells in each enrichment culture.
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Affiliation(s)
- Ulrike Jaekel
- Department of Microbiology, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Niculina Musat
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Birgit Adam
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Marcel Kuypers
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Olav Grundmann
- Department of Microbiology, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Florin Musat
- Department of Microbiology, Max Planck Institute for Marine Microbiology, Bremen, Germany
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Bouvier T, Del Giorgio PA. Factors influencing the detection of bacterial cells using fluorescence in situ hybridization (FISH): A quantitative review of published reports. FEMS Microbiol Ecol 2012; 44:3-15. [PMID: 19719646 DOI: 10.1016/s0168-6496(02)00461-0] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Abstract Fluorescence in situ hybridization (FISH) is widely used to describe bacterial community composition and, to a lesser extent, to describe the physiological state of cells. One of the limitations of the technique is that the effectiveness of the detection of target cells appears to vary widely. Here, we present a quantitative review of published reports on the percentage of cells detected using the common EUB338 probe (%Eub) in aquatic ecosystems. The %Eub varies from 1 to 100% in the different published reports, with an average of 56%. There is a methodological component in this variation, with a significant effect of the fluorochrome type and the stringency conditions of the reaction. But there is also a strong environmental component, and the type of ecosystem and dominant phylogenetic group significantly influence %Eub. We argue that the optimization of the FISH protocol to describe the phylogenetic composition of bacterial assemblages will probably lead to techniques that are not effective to describe the physiological state of cells.
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Affiliation(s)
- Thierry Bouvier
- Dépt. des Sciences Biologiques, Université du Québec à Montréal, CP 8888, Succ. Centre Ville, Montréal, QC, Canada H3C 3P8
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Bouali M, Pelletier E, Chaussonnerie S, Le Paslier D, Bakhrouf A, Sghir A. Characterization of rhizosphere prokaryotic diversity in a horizontal subsurface flow constructed wetland using a PCR cloning-sequencing based approach. Appl Microbiol Biotechnol 2012; 97:4221-31. [DOI: 10.1007/s00253-012-4239-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 06/09/2012] [Accepted: 06/11/2012] [Indexed: 11/28/2022]
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Wilson SL, Frazer C, Cumming BF, Nuin PAS, Walker VK. Cross-tolerance between osmotic and freeze-thaw stress in microbial assemblages from temperate lakes. FEMS Microbiol Ecol 2012; 82:405-15. [PMID: 22551442 DOI: 10.1111/j.1574-6941.2012.01404.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 04/21/2012] [Accepted: 04/25/2012] [Indexed: 12/01/2022] Open
Abstract
Osmotic stress can accompany increases in solute concentrations because of freezing or high-salt environments. Consequently, microorganisms from environments with a high-osmotic potential may exhibit cross-tolerance to freeze stress. To test this hypothesis, enrichments derived from the sediment and water of temperate lakes with a range of salt concentrations were subjected to multiple freeze-thaw cycles. Surviving isolates were identified and metagenomes were sampled prior to and following selection. Enrichments from alkali lakes were typically the most freeze-thaw resistant with only 100-fold losses in cell viability, and those from freshwater lakes were most susceptible, with cell numbers reduced at least 100,000-fold. Metagenomic analysis suggested that selection reduced assemblage diversity more in freshwater samples than in those from saline lakes. Survivors included known psychro-, halo- and alkali-tolerant bacteria. Characterization of freeze-thaw-resistant isolates from brine and alkali lakes showed that few isolates had ice-associating activities such as antifreeze or ice nucleation properties. However, all brine- and alkali-derived isolates had high intracellular levels of osmolytes and/or appeared more likely to form biofilms. Conversely, these phenotypes were infrequent amongst the freshwater-derived isolates. These observations are consistent with microbial cross-tolerance between osmotic and freeze-thaw stresses.
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Affiliation(s)
- Sandra L Wilson
- Department of Biology, Queen's University, Kingston, ON, Canada
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Saha R, Donofrio RS. The microbiology of metalworking fluids. Appl Microbiol Biotechnol 2012; 94:1119-30. [DOI: 10.1007/s00253-012-4055-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2012] [Revised: 03/20/2012] [Accepted: 03/23/2012] [Indexed: 10/28/2022]
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Wilson SL, Grogan P, Walker VK. Prospecting for ice association: characterization of freeze-thaw selected enrichment cultures from latitudinally distant soils. Can J Microbiol 2012; 58:402-12. [PMID: 22435705 DOI: 10.1139/w2012-010] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Freeze-thaw stress has previously been shown to alter soil community structure and function. We sought to further investigate this stress on enriched microbial consortia with the aim of identifying microbes with ice-associating adaptations that facilitate survival. Enrichments were established to obtain culturable psychrotolerant microbes from soil samples from the latitudinal extremes of the Canadian Shield plateau. The resulting consortia were subjected to consecutive freeze-thaw cycles, and survivors were putatively identified by their 16S rRNA gene sequences. Even though the northerly site was exposed to longer, colder winters and large spring-time temperature fluctuations, the selective regime similarly affected both enriched consortia. Quantitative PCR and metagenomic sequencing were used to determine the frequency of a subset of the resistant microbes in the original enrichments. The metagenomes showed 22 initial genera, only 6 survived and these were not dominant prior to selection. When survivors were assayed for ice recrystallization inhibition and ice nucleation activities, over 60% had at least one of these properties. These phenotypes were not more prevalent in the northern enrichment, indicating that regarding these adaptations, the enrichment strategy yielded seemingly functionally similar consortia from each site.
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Affiliation(s)
- Sandra L Wilson
- Department of Biology, Queen's University, Kingston, ON K7L 3N6, Canada
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Abed RMM. Detection and Capturing of (14)C Radioactively-Labeled Small Subunit rRNA from Mixed Microbial Communities of a Microbial Mat Using Magnetic Beads. Indian J Microbiol 2012; 52:88-93. [PMID: 23449550 PMCID: PMC3298593 DOI: 10.1007/s12088-011-0239-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 08/23/2011] [Accepted: 10/13/2011] [Indexed: 10/16/2022] Open
Abstract
Carbon cycling in the hypersaline microbial mats from Chiprana Lake, Spain is primarily dependent on phototrophic microorganisms with the ability to fix CO2 into organics that can be further utilized by aerobic as well as anaerobic heterotrophic bacteria. Here, mat pieces were incubated in seawater amended with (14)C sodium bicarbonate and the incorporation of the radiocarbon in the small subunit ribosomal RNA (SSU rRNA) of mat organisms was followed using scintillation counter and autoradiography. Different domains of SSU rRNA were separated from the total RNA by means of streptavidin-coated magnetic beads and biotin-labeled oligonucleotide probes. The (14)C label was detected in isolated RNA by both scintillation counter and autoradiography, however the latter technique was less sensitive. Using scintillation counter, the radiolabel incorporation increased with time with a maximum rate of 0.18 Bq ng(-1) detected after 25 days. The bacterial SSU rRNA could be captured using the magnetic beads, however the hybridization efficiency was around 20%. The captured RNA was radioactively labeled, which could be mainly due to the fixation of radiocarbon by phototrophic organisms. In conclusion, the incubation of microbial mats in the presence of radiolabeled bicarbonate leads to the incorporation of the (14)C label into RNA molecules through photosynthesis and this label can be detected using scintillation counter. The used approach could be useful in studying the fate of fixed carbon and its uptake by other microorganisms in complex microbial mats, particularly when species-specific probes are used and the hybridization efficiency and RNA yield are further optimized.
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Affiliation(s)
- Raeid M. M. Abed
- Biology Department, College of Science, Sultan Qaboos University, P.O.Box 36, Al Khoud, 123 Muscat, Sultanate of Oman
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Muller F, Brissac T, Le Bris N, Felbeck H, Gros O. First description of giant Archaea (Thaumarchaeota) associated with putative bacterial ectosymbionts in a sulfidic marine habitat. Environ Microbiol 2011; 12:2371-83. [PMID: 21966926 DOI: 10.1111/j.1462-2920.2010.02309.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Archaea may be involved in global energy cycles, and are known for their ability to interact with eukaryotic species (sponges, corals and ascidians) or as archaeal-bacterial consortia. The recently proposed phylum Thaumarchaeota may represent the deepest branching lineage in the archaeal phylogeny emerging before the divergence between Euryarchaeota and Crenarchaeota. Here we report the first characterization of two marine thaumarchaeal species from shallow waters that consist of multiple giant cells. One species is coated with sulfur-oxidizing γ-Proteobacteria. These new uncultured thaumarchaeal species are able to live in the sulfide-rich environments of a tropical mangrove swamp, either on living tissues such as roots or on various kinds of materials such as stones, sunken woods, etc. These archaea and archaea/bacteria associations have been studied using light microscopy, transmission electron microscopy and scanning electron microscopy. Species identification of archaeons and the putative bacterial symbiont have been assessed by 16S small subunit ribosomal RNA analysis. The sulfur-oxidizing ability of the bacteria has been assessed by genetic investigation on alpha-subunit of the adenosine-5'-phosphosulfate reductase/oxidase's (AprA). Species identifications have been confirmed by fluorescence in situ hybridization using specific probes designed in this study. In this article, we describe two new giant archaeal species that form the biggest archaeal filaments ever observed. One of these species is covered by a specific biofilm of sulfur-oxidizing γ-Proteobacteria. This study highlights an unexpected morphological and genetic diversity of the phylum Thaumarchaeota.
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Affiliation(s)
- Félix Muller
- Université des Antilles et de la Guyane UFR des Sciences Exactes et Naturelles Département de Biologie, BP 592. 97159 Pointe-à-Pitre cedex, Guadeloupe, France.
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Baati H, Jarboui R, Gharsallah N, Sghir A, Ammar E. Molecular community analysis of magnesium-rich bittern brine recovered from a Tunisian solar saltern. Can J Microbiol 2011; 57:975-81. [PMID: 22107448 DOI: 10.1139/w11-088] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The microbial community of a magnesium-rich bittern brine saturated with NaCl (380-400 g/L) from a Tunisian solar saltern was investigated using a molecular approach based on 16S rRNA gene analysis and viability tests. The results revealed the existence of microbial flora. Viability test assessment showed that 46.4% of this flora was viable but not detectable by culturability tests. 16S rRNA genes from 49 bacterial clones and 38 archaeal clones were sequenced and phylogenetically analyzed. Eleven operational taxonomic units (OTUs) determined by the DOTUR program with 97% sequence similarity were generated for Bacteria. These OTUs were affiliated with Bacteroidetes and Gammaproteobacteria. The archaeal community composition exhibited more diversity with 38 clones, resulting in 13 OTUs affiliated with the Euryarchaeota phylum. Diversity measurement showed a more diverse archaeal than bacterial community at the saturated pond.
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Affiliation(s)
- Houda Baati
- a Université de Sfax, École Nationale d'Ingénieurs de Sfax - LARSEN, UR Étude et Gestion des Environnements Côtier et Urbain, B.P. 1173 - 3038 Sfax, Tunisia
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Kim YH, Kim IS, Moon EY, Park JS, Kim SJ, Lim JH, Park BT, Lee EJ. High abundance and role of antifungal bacteria in compost-treated soils in a wildfire area. Microb Ecol 2011; 62:725-737. [PMID: 21409344 DOI: 10.1007/s00248-011-9839-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 02/23/2011] [Indexed: 05/30/2023]
Abstract
Compost has been widely used in order to promote vegetation growth in post-harvested and burned soils. The effects on soil microorganisms were scarcely known, so we performed the microbial analyses in a wildfire area of the Taebaek Mountains, Korea, during field surveys from May to September 2007. Using culture-dependent and -independent methods, we found that compost used in burned soils influenced a greater impact on soil fungi than bacteria. Compost-treated soils contained higher levels of antifungal strains in the genera Bacillus and Burkholderia than non-treated soils. When the antifungal activity of Burkholderia sp. strain O1a_RA002, which had been isolated from a compost-treated soil, was tested for the growth inhibition of bacteria and fungi isolated from burned soils, the membrane-filtered culture supernatant inhibited 19/37 fungal strains including soil fungi, Eupenicillium spp. and Devriesia americana; plant pathogens, Polyschema larviformis and Massaria platani; an animal pathogen, Mortierella verticillata; and an unidentified Ascomycota. However, this organism only inhibited 11/151 bacterial strains tested. These patterns were compatible with the culture-independent DGGE results, suggesting that the compost used in burned soils had a greater impact on soil fungi than bacteria through the promotion of the growth of antifungal bacteria. Our findings indicate that compost used in burned soils is effective in restoring soil conditions to a state closer to those of nearby unburned forest soils at the early stage of secondary succession.
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Affiliation(s)
- Yong-Hak Kim
- Department of Microbiology, School of Medicine, Catholic University of Daegu, Daegu 705-718, Republic of Korea
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Kristiansen A, Pedersen KH, Nielsen PH, Nielsen LP, Nielsen JL, Schramm A. Bacterial community structure of a full-scale biofilter treating pig house exhaust air. Syst Appl Microbiol 2011; 34:344-52. [DOI: 10.1016/j.syapm.2010.11.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Accepted: 11/19/2010] [Indexed: 11/23/2022]
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Juretschko S, Fritsche TR. Applications of Fluorescence In Situ Hybridization in Diagnostic Microbiology. In: Persing DH, Tenover FC, Tang Y, Nolle FS, Hayden RT, van Belkum A, editors. Molecular Microbiology. Wiley; 2011. pp. 1-19. [DOI: 10.1128/9781555816834.ch1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hinck S, Mussmann M, Salman V, Neu TR, Lenk S, Beer DD, Jonkers HM. Vacuolated Beggiatoa-like filaments from different hypersaline environments form a novel genus. Environ Microbiol 2011; 13:3194-205. [PMID: 21651683 DOI: 10.1111/j.1462-2920.2011.02513.x] [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: 11/26/2022]
Abstract
In this study, members of a specific group of thin (6-14 µm filament diameter), vacuolated Beggiatoa-like filaments from six different hypersaline microbial mats were morphologically and phylogenetically characterized. Therefore, enrichment cultures were established, filaments were stained with fluorochromes to show intracellular structures and 16S rRNA genes were sequenced. Morphological characteristics of Beggiatoa-like filaments, in particular the presence of intracellular vacuoles, and the distribution of nucleic acids were visualized. In the intracellular vacuole nitrate reached concentrations of up to 650 mM. Fifteen of the retrieved 16S rRNA gene sequences formed a monophyletic cluster and were phylogenetically closely related (≥ 94.4% sequence identity). Sequences of known filamentous sulfide-oxidizing genera Beggiatoa and Thioploca that comprise non-vacuolated and vacuolated filaments from diverse habitats clearly delineated from this cluster. The novel monophyletic cluster was furthermore divided into two sub-clusters: one contained sequences originating from Guerrero Negro (Mexico) microbial mats and the other comprised sequences from five distinct Spanish hypersaline microbial mats from Ibiza, Formentera and Lake Chiprana. Our data suggest that Beggiatoa-like filaments from hypersaline environments displaying a thin filament diameter contain nitrate-storing vacuoles and are phylogenetically separate from known Beggiatoa. Therefore, we propose a novel genus for these organisms, which we suggest to name 'Candidatus Allobeggiatoa'.
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Affiliation(s)
- Susanne Hinck
- Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359 Bremen, Germany.
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Kumar S, Dagar SS, Mohanty AK, Sirohi SK, Puniya M, Kuhad RC, Sangu KPS, Griffith GW, Puniya AK. Enumeration of methanogens with a focus on fluorescence in situ hybridization. Naturwissenschaften 2011; 98:457-72. [PMID: 21475941 DOI: 10.1007/s00114-011-0791-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 03/19/2011] [Accepted: 03/20/2011] [Indexed: 10/18/2022]
Abstract
Methanogens, the members of domain Archaea are potent contributors in global warming. Being confined to the strict anaerobic environment, their direct cultivation as pure culture is quite difficult. Therefore, a range of culture-independent methods have been developed to investigate their numbers, substrate uptake patterns, and identification in complex microbial communities. Unlike other approaches, fluorescence in situ hybridization (FISH) is not only used for faster quantification and accurate identification but also to reveal the physiological properties and spatiotemporal dynamics of methanogens in their natural environment. Aside from the methodological aspects and application of FISH, this review also focuses on culture-dependent and -independent techniques employed in enumerating methanogens along with associated problems. In addition, the combination of FISH with micro-autoradiography that could also be an important tool in investigating the activities of methanogens is also discussed.
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Affiliation(s)
- Sanjay Kumar
- Dairy Microbiology Division, National Dairy Research Institute, Karnal 132001, India
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Zeder M, Ellrott A, Amann R. Automated sample area definition for high-throughput microscopy. Cytometry A 2011; 79:306-10. [DOI: 10.1002/cyto.a.21034] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Accepted: 01/24/2011] [Indexed: 01/18/2023]
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Kragelund C, Thomsen TR, Mielczarek AT, Nielsen PH. Eikelboom's morphotype 0803 in activated sludge belongs to the genus Caldilinea in the phylum Chloroflexi. FEMS Microbiol Ecol 2011; 76:451-62. [PMID: 21299573 DOI: 10.1111/j.1574-6941.2011.01065.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Micromanipulated filamentous bacteria from bulking and foaming activated sludge morphologically identified as Eikelboom type 0803 were shown to be affiliated to the genus Caldilinea within the phylum Chloroflexi. Specific FISH probes were designed for their in situ detection and quantification in seven Danish wastewater treatment plants with biological nutrient removal. The survey applied all species-specific probes for Chloroflexi of relevance in activated sludge treatment plants as well as the phylum-specific probes. Type 0803 filaments constituted around 20% of the total Chloroflexi population. In four of the treatment plants, type 0803 and type 0092 co-occurred and were the dominating fraction of the Chloroflexi population. In the other plants, most Chloroflexi could not be identified beyond the phylum level, suggesting a yet far larger diversity. On average, for all plants, the total Chloroflexi population constituted 12% of the entire microbial population and seems to play an important structural role in the sludge floc formation. Ecophysiological characterization of type 0803 showed their potential role in macromolecule conversion as evident by high levels of exoenzyme expression. Acetate was not consumed. Glucose was consumed with oxygen, nitrite and nitrite as electron acceptors, suggesting that type 0803 may be a denitrifier. Their surfaces were hydrophobic, explaining their occasional occurrence in foaming incidents.
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Affiliation(s)
- Caroline Kragelund
- Department of Biotechnology, Chemistry and Environmental Engineering, Section of Biotechnology, Aalborg University, Aalborg, Denmark
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McFeters G, Pyle B, Lisle J, Broadaway S. Rapid direct methods for enumeration of specific, active bacteria in water and biofilms. J Appl Microbiol 2010; 85 Suppl 1:193S-200S. [DOI: 10.1111/j.1365-2672.1998.tb05299.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Theron J, Eugene Cloete T, de Kwaadsteniet M. Current molecular and emerging nanobiotechnology approaches for the detection of microbial pathogens. Crit Rev Microbiol 2010; 36:318-39. [DOI: 10.3109/1040841x.2010.489892] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Barbeyron T, Lerat Y, Sassi JF, Le Panse S, Helbert W, Collén PN. Persicivirga ulvanivorans sp. nov., a marine member of the family Flavobacteriaceae that degrades ulvan from green algae. Int J Syst Evol Microbiol 2010; 61:1899-1905. [PMID: 20833882 DOI: 10.1099/ijs.0.024489-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [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 rod shaped, Gram-stain-negative, chemo-organotrophic, heterotrophic, strictly aerobic, non-gliding bacterium, designated strain PLR(T), was isolated from faeces of the mollusc Aplysia punctata (Mollusca, Gastropoda) that had been fed with green algae belonging to the genus Ulva. The novel strain was able to degrade ulvan, a polysaccharide extracted from green algae (Chlorophyta, Ulvophyceae). The taxonomic position of strain PLR(T) was investigated by using a polyphasic approach. Strain PLR(T) was dark orange, oxidase-positive, catalase-positive and grew optimally at 25 °C, at pH 7.5 and in the presence of 2.5 % (w/v) NaCl with an oxidative metabolism using oxygen as the electron acceptor. Nitrate could not be used as the electron acceptor. Strain PLR(T) had a Chargaff's coefficient (DNA G+C content) of 35.3 mol%. Phylogenetic analysis based on the sequence of the 16S rRNA gene placed the novel strain in the family Flavobacteriaceae (phylum 'Bacteroidetes'), within a clade comprising Stenothermobacter spongiae, Nonlabens tegetincola, Sandarakinotalea sediminis, Persicivirga xylanidelens and Persicivirga dokdonensis. The closest neighbours of strain PLR(T) were P. xylanidelens and P. dokdonensis, sharing 95.2 and 95.5 % 16S rRNA gene sequence similarity, respectively. Phylogenetic inference and differential phenotypic characteristics demonstrated that strain PLR(T) represents a novel species of the genus Persicivirga, for which the name Persicivirga ulvanivorans sp. nov. is proposed. The type strain is PLR(T) ( = CIP 110082(T) = DSM 22727(T)).
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Affiliation(s)
- Tristan Barbeyron
- Centre National de la Recherche Scientifique, Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche 7139 'Marine Plants and Biomolecules', Station Biologique, F-29682 Roscoff Cedex, Bretagne, France
| | - Yannick Lerat
- Centre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, Bretagne, France
| | - Jean-François Sassi
- Centre d'Etudes et de Valorisation des Algues, Presqu'île de Pen Lan, BP3, 22610 Pleubian, Bretagne, France
| | - Sophie Le Panse
- Centre National de la Recherche Scientifique, Université Pierre et Marie Curie-Paris 6, FR2424 Service d'Imagerie, Station Biologique, F-29682 Roscoff Cedex, Bretagne, France
| | - William Helbert
- Centre National de la Recherche Scientifique, Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche 7139 'Marine Plants and Biomolecules', Station Biologique, F-29682 Roscoff Cedex, Bretagne, France
| | - Pi Nyvall Collén
- Centre National de la Recherche Scientifique, Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche 7139 'Marine Plants and Biomolecules', Station Biologique, F-29682 Roscoff Cedex, Bretagne, France
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Abstract
Bacteria with limited genomic cross-hybridization were isolated from soil contaminated with C5+, a mixture of hydrocarbons, and identified by partial 16S rRNA sequencing. Filters containing denatured genomic DNAs were used in a reverse sample genome probe (RSGP) procedure for analysis of the effect of an easily degradable compound (toluene) and a highly recalcitrant compound (dicyclopentadiene [DCPD]) on community composition. Hybridization with labeled total-community DNA isolated from soil exposed to toluene indicated enrichment of several Pseudomonas spp., which were subsequently found to be capable of toluene mineralization. Hybridization with labeled total-community DNA isolated from soil exposed to DCPD indicated enrichment of a Pseudomonas sp. or a Sphingomonas sp. These two bacteria appeared capable of producing oxygenated DCPD derivatives in the soil environment, but mineralization could not be shown. These results demonstrate that bacteria, which metabolize degradable or recalcitrant hydrocarbons, can be identified by the RSGP procedure.
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Affiliation(s)
- Y Shen
- Department of Biological Sciences, The University of Calgary, Calgary, Alberta, Canada T2N 1N4, and NOVA Research and Technology Centre, Calgary, Alberta, Canada T2E 7K7
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Abstract
Microbial consortia may harbour an array of resistance mechanisms that facilitate survival under harsh conditions, including antifreeze and ice-nucleation proteins. Antifreeze proteins lower freezing points as well as inhibit the growth of large, potentially damaging ice crystals from small ice embryos. In contrast, ice-nucleation proteins prevent supercooling and allow ice formation at high, sub-zero temperatures. Psychrophiles and psychrotolerant microbes are typically sought in extremely cold environments. However, given that geography is unlikely to present an insurmountable barrier to microbial dispersal, we reasoned that species with low-temperature adaptations should also be present, although rare, in more temperate environments. In consequence, the challenge then becomes one of selecting for rare microbes present in a larger community. Following the introductory commentary, we demonstrate that both freeze-thaw survival and ice-affinity selection can be used to identify microbes, which demonstrate low-temperature resistance, from enrichments derived from temperate environments. Selection resulted in a drastic decrease in cell abundance and diversity, allowing the isolation of a subset of resistant microbes. Depending on the origin of the consortia, these resistant microbes demonstrated cross-tolerance to osmotic stress, or a high proportion of antifreeze and/or ice-nucleation protein activities. Both types of ice-associating proteins presumably facilitate microbial survival at low temperatures. These proteins, as well as molecules that maintain osmotic balance, are also of commercial interest, with applications in the food, energy and medical industries. In addition, the resistant phenotypes described here provide a glimpse into the breadth of strategies microbes use to survive and thrive at low temperatures.
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Affiliation(s)
- Sandra L Wilson
- Department of Biology, Queen's University, 116 Barrie Street, Kingston, Ontario, Canada K7L 3N6
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