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Roslund K, Lehto M, Pussinen P, Groop PH, Halonen L, Metsälä M. On-line profiling of volatile compounds produced in vitro by pathogenic oral bacteria. J Breath Res 2019; 14:016010. [PMID: 31698353 DOI: 10.1088/1752-7163/ab5559] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Infections by oral pathogens are one of the most common health problems worldwide. Due to the intimate connection between exhaled breath and the oral cavity, breath analysis could potentially be used to diagnose these infections. However, little is known about the volatile emissions of important oral pathogens that are connected with gingivitis and periodontitis. In this study, we have performed in vitro headspace measurements on four important oral pathogens (P. gingivalis, T. forsythia, P. intermedia and P. nigrescens) using proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS). Some of the most abundant compounds produced by the bacteria include hydrogen sulphide, methanethiol, acetone, dimethylsulphide, isoprene, cyclopentanone and indole as tentatively assigned from the mass spectra. Several other abundant mass signals were recorded but the assignment of these is less certain. Some of the bacterial species can be separated from each other by the emitted volatile fingerprints. The results of this study can be used in potential development of a diagnostic breath test for oral infections. In addition, as several of the measured compounds are known to be toxic, the results point to an intriguing possibility of studying the connection between the bacterial virulence and the emitted volatile compounds.
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Affiliation(s)
- Kajsa Roslund
- Department of Chemistry, University of Helsinki, Helsinki, Finland
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Calcagnile M, Tredici SM, Talà A, Alifano P. Bacterial Semiochemicals and Transkingdom Interactions with Insects and Plants. INSECTS 2019; 10:E441. [PMID: 31817999 PMCID: PMC6955855 DOI: 10.3390/insects10120441] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 01/08/2023]
Abstract
A peculiar feature of all living beings is their capability to communicate. With the discovery of the quorum sensing phenomenon in bioluminescent bacteria in the late 1960s, it became clear that intraspecies and interspecies communications and social behaviors also occur in simple microorganisms such as bacteria. However, at that time, it was difficult to imagine how such small organisms-invisible to the naked eye-could influence the behavior and wellbeing of the larger, more complex and visible organisms they colonize. Now that we know this information, the challenge is to identify the myriad of bacterial chemical signals and communication networks that regulate the life of what can be defined, in a whole, as a meta-organism. In this review, we described the transkingdom crosstalk between bacteria, insects, and plants from an ecological perspective, providing some paradigmatic examples. Second, we reviewed what is known about the genetic and biochemical bases of the bacterial chemical communication with other organisms and how explore the semiochemical potential of a bacterium can be explored. Finally, we illustrated how bacterial semiochemicals managing the transkingdom communication may be exploited from a biotechnological point of view.
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Affiliation(s)
| | | | | | - Pietro Alifano
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Prov.le Lecce-Monteroni, 73100 Lecce, Italy; (M.C.); (S.M.T.); (A.T.)
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Effect of Marine Bacteria and Ulvan on the Activity of Antioxidant Defense Enzymes and the Bio-Protection of Papaya Fruit against Colletotrichum gloeosporioides. Antioxidants (Basel) 2019; 8:antiox8120580. [PMID: 31771146 PMCID: PMC6943524 DOI: 10.3390/antiox8120580] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/12/2019] [Accepted: 11/20/2019] [Indexed: 12/21/2022] Open
Abstract
Anthracnose, caused by Colletotrichum gloeosporioides, is one of the most important diseases in papaya fruit. Its control has been achieved with synthetic fungicides, but the application of marine bacteria and the sulphated polysaccharide ulvan (structural description: β[1,4]-D-GlcA-α[1,4]-L-Rha 3 sulfate, β[1,4]-L-IdoA-α[1,4]-L-Rha 3 sulfate, β[1,4]-D-Xyl-α[1,4]-L-Rha 3 sulfate, and β[1,4]-D-Xyl 2-sulfate-α[1,4]-L-Rha 3 sulfate) from Ulva sp. can be an alternative in the use of agrochemicals. Thus, the objective of this study was to assess the effect in vitro and in vivo of two marine bacteria, Stenotrophomonas rhizophila and Bacillus amyloliquefaciens, and ulvan in papaya fruit’s bio-protection against C. gloeosporioides. The capacity of marine bacteria to inhibit mycelial growth and phytopathogen spore germination in vitro through volatile organic compounds (VOCs) and carbohydrate competition was evaluated. Fruit was inoculated with bacteria, ulvan, and C. gloeosporioides and incubated at 25 °C and 90% of relative humidity (RH) for seven days. Disease incidence (%), lesion diameter (mm), and antioxidant defense enzyme activity (such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were quantified. In vitro, C. gloeosporioides was inhibited by S. rhizophila and B. amyloliquefaciens. In vivo, disease incidence and the lesion diameter of anthracnose on papaya fruit were significantly reduced by marine bacteria and ulvan. Antioxidant defense enzyme activity played an important role in fruit bio-protection against C. gloeosporioides. The application of marine bacteria and ulvan can be an alternative in the sustainable postharvest management of papaya.
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54
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Avalos M, Garbeva P, Raaijmakers JM, van Wezel GP. Production of ammonia as a low-cost and long-distance antibiotic strategy by Streptomyces species. ISME JOURNAL 2019; 14:569-583. [PMID: 31700119 DOI: 10.1038/s41396-019-0537-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 09/20/2019] [Accepted: 09/26/2019] [Indexed: 02/07/2023]
Abstract
Soil-inhabiting streptomycetes are nature's medicine makers, producing over half of all known antibiotics and many other bioactive natural products. However, these bacteria also produce many volatiles, molecules that disperse through the soil matrix and may impact other (micro)organisms from a distance. Here, we show that soil- and surface-grown streptomycetes have the ability to kill bacteria over long distances via air-borne antibiosis. Our research shows that streptomycetes do so by producing surprisingly high amounts of the low-cost volatile ammonia, dispersing over long distances to inhibit the growth of Gram-positive and Gram-negative bacteria. Glycine is required as precursor to produce ammonia, and inactivation of the glycine cleavage system nullified ammonia biosynthesis and concomitantly air-borne antibiosis. Reduced expression of the porin master regulator OmpR and its cognate kinase EnvZ is used as a resistance strategy by E. coli cells to survive ammonia-mediated antibiosis. Finally, ammonia was shown to enhance the activity of canonical antibiotics, suggesting that streptomycetes adopt a low-cost strategy to sensitize competitors for antibiosis from a distance.
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Affiliation(s)
- Mariana Avalos
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands
| | - Jos M Raaijmakers
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.,Department of Microbial Ecology, Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands
| | - Gilles P van Wezel
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands. .,Department of Microbial Ecology, Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB, Wageningen, The Netherlands.
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55
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Li X, Garbeva P, Liu X, Klein Gunnewiek PJA, Clocchiatti A, Hundscheid MPJ, Wang X, de Boer W. Volatile-mediated antagonism of soil bacterial communities against fungi. Environ Microbiol 2019; 22:1025-1035. [PMID: 31580006 PMCID: PMC7064993 DOI: 10.1111/1462-2920.14808] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/13/2019] [Accepted: 09/18/2019] [Indexed: 11/30/2022]
Abstract
Competition is a major type of interaction between fungi and bacteria in soil and is also an important factor in suppression of plant diseases caused by soil‐borne fungal pathogens. There is increasing attention for the possible role of volatiles in competitive interactions between bacteria and fungi. However, knowledge on the actual role of bacterial volatiles in interactions with fungi within soil microbial communities is lacking. Here, we examined colonization of sterile agricultural soils by fungi and bacteria from non‐sterile soil inoculums during exposure to volatiles emitted by soil‐derived bacterial communities. We found that colonization of soil by fungi was negatively affected by exposure to volatiles emitted by bacterial communities whereas that of bacteria was barely changed. Furthermore, there were strong effects of bacterial community volatiles on the assembly of fungal soil colonizers. Identification of volatile composition produced by bacterial communities revealed several compounds with known fungistatic activity. Our results are the first to reveal a collective volatile‐mediated antagonism of soil bacteria against fungi. Given the better exploration abilities of filamentous fungi in unsaturated soils, this may be an important strategy for bacteria to defend occupied nutrient patches against invading fungi. Another implication of our research is that bacterial volatiles in soil atmospheres can have a major contribution to soil fungistasis.
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Affiliation(s)
- Xiaogang Li
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China.,Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, Wageningen, 6708 PB, The Netherlands.,CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, Wageningen, 6708 PB, The Netherlands
| | - Xiaojiao Liu
- Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, Wageningen, 6708 PB, The Netherlands.,College of Plant Protection, Southwest University, Chongqing, 400715, China
| | - Paulien J A Klein Gunnewiek
- Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, Wageningen, 6708 PB, The Netherlands
| | - Anna Clocchiatti
- Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, Wageningen, 6708 PB, The Netherlands
| | - Maria P J Hundscheid
- Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, Wageningen, 6708 PB, The Netherlands
| | - Xingxiang Wang
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Wietse de Boer
- Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, Wageningen, 6708 PB, The Netherlands.,Soil Biology Group, Wageningen University, Wageningen, 6708 PB, The Netherlands
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56
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Khan S, Voordouw MJ, Hill JE. Competition Among Gardnerella Subgroups From the Human Vaginal Microbiome. Front Cell Infect Microbiol 2019; 9:374. [PMID: 31737577 PMCID: PMC6834547 DOI: 10.3389/fcimb.2019.00374] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 10/16/2019] [Indexed: 11/13/2022] Open
Abstract
Gardnerella spp. are hallmarks of bacterial vaginosis, a clinically significant dysbiosis of the vaginal microbiome. Gardnerella has four subgroups (A, B, C, and D) based on cpn60 sequences. Multiple subgroups are often detected in individual women, and interactions between these subgroups are expected to influence their population dynamics and associated clinical signs and symptoms of bacterial vaginosis. In the present study, contact-independent and contact-dependent interactions between the four Gardnerella subgroups were investigated in vitro. The cell free supernatants of mono- and co-cultures had no effect on growth rates of the Gardnerella subgroups suggesting that there are no contact-independent interactions (and no contest competition). For contact-dependent interactions, mixed communities of 2, 3, or 4 subgroups were created and the initial (0 h) and final population sizes (48 h) were quantified using subgroup-specific PCR. Compared to the null hypothesis of neutral interactions, most (69.3%) of the mixed communities exhibited competition. Competition reduced the growth rates of subgroups A, B, and C. In contrast, the growth rate of subgroup D increased in the presence of the other subgroups. All subgroups were able to form biofilm alone and in mixed communities. Our study suggests that there is scramble competition among Gardnerella subgroups, which likely contributes to the observed distributions of Gardnerella spp. in vaginal microbiomes and the formation of the multispecies biofilms characteristic of bacterial vaginosis.
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Affiliation(s)
- Salahuddin Khan
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Maarten J Voordouw
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Janet E Hill
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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57
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Janssens TKS, Tyc O, Besselink H, de Boer W, Garbeva P. Biological activities associated with the volatile compound 2,5-bis(1-methylethyl)-pyrazine. FEMS Microbiol Lett 2019; 366:5304172. [PMID: 30698709 DOI: 10.1093/femsle/fnz023] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/28/2019] [Indexed: 12/13/2022] Open
Abstract
Pyrazines are 1,4-diazabenzene-based volatile organic compounds and known for their broad-spectrum antimicrobial activity. In the present study, we assessed the antimicrobial activity of 2,5-bis(1-methylethyl)-pyrazine, produced by Paenibacillus sp. AD87 during co-culture with Burkholderia sp. AD24. In addition, we were using transcriptional reporter assays in E. coli and mammalian cells to decipher the possible mode of action. Bacterial and mammalian luciferase reporter strains were deployed to elucidate antimicrobial and toxicological effects of 2,5-bis(1-methylethyl)-pyrazine. At high levels of exposure, 2,5-bis(1-methylethyl)-pyrazine exerted strong DNA damage response. At lower concentrations, cell-wall damage response was observed. The activity was corroborated by a general toxicity reporter assay in E. coli ΔampD, defective in peptidoglycan turnover. The maximum E. coli cell-wall stress activity was measured at a concentration close to the onset of the mammalian cytotoxicity, while other adverse outcome pathways, such as the activation of aryl hydrocarbon and estrogenic receptor, the p53 tumour suppressor and the oxidative stress-related Nrf2 transcription factor, were induced at elevated concentrations compared to the response of mammalian cells. Because of its broad-spectrum antimicrobial activity at lower concentrations and the relatively low mammalian toxicity, 2,5-bis(1-methylethyl)-pyrazine is a potential bio-based fumigant with possible applications in food industry, agriculture or logistics.
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Affiliation(s)
- Thierry K S Janssens
- MicroLife Solutions B.V., Science Park 406, 1098 XH Amsterdam, the Netherlands.,National Institute for Public Health and the Environment (RIVM), Centre for Infectious Diseases, Epidemiology and Surveillance, Endemic and Emerging Viruses section, Antonie van Leeuwenhoeklaan 9, 37221 MA Bilthoven, the Netherlands
| | - Olaf Tyc
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB Wageningen, the Netherlands
| | - Harrie Besselink
- BioDetection Systems B.V., Science Park 406, 1098 XH Amsterdam, the Netherlands
| | - Wietse de Boer
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB Wageningen, the Netherlands.,Soil Biology Group, Wageningen University and Research Centre (WUR), PO BOX 47, 6700 AA Wageningen, the Netherlands
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB Wageningen, the Netherlands
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58
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Serasanambati M, Broza YY, Haick H. Volatile Compounds Are Involved in Cellular Crosstalk and Upregulation. ACTA ACUST UNITED AC 2019; 3:e1900131. [PMID: 32648725 DOI: 10.1002/adbi.201900131] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/16/2019] [Indexed: 12/14/2022]
Abstract
Cell-cell cross talk is of great importance in cancer research due to its major role in proliferation, differentiation, migration, and influence on the apoptotic pathway. Different cell-cell communication mechanisms have come mainly from proteomic and genomic approaches. In this paper, a new route is reported for cross talk between cancer cells that occurs, even when they are far away from each other. Single-cell and culture analysis shows that upregulation of cancer cells emits hundreds of volatile organic compounds (VOCs) into their headspace. Part of the VOCs remains without any change, disregarding the biological environment around it. The other part of the VOCs is exchanged between monocultures of the cells as well as between co-cultures of the cells with no physical contact between them, leading to different changes in growth than when left on their own. The chemical nature and composition of these VOCs have been determined and are discussed herein. Cell-to-cell cross talk has the advantage of being suitable for transfer/diffusion over relatively long distances. It would thus be expected to serve as a shuttling pad toward the development of advanced approaches that could enable very early detection of cancer and/or monitoring of metastasis and related cancer therapy.
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Affiliation(s)
- Mamatha Serasanambati
- Department of Chemical Engineering, Technion - Israel Institute of Technology, Technion City, Haifa, 3200003, Israel
| | - Yoav Y Broza
- Department of Chemical Engineering, Technion - Israel Institute of Technology, Technion City, Haifa, 3200003, Israel
| | - Hossam Haick
- Department of Chemical Engineering, Technion - Israel Institute of Technology, Technion City, Haifa, 3200003, Israel.,Russell Berries Nanotechnology Institute, Technion - Israel Institute of Technology, Technion City, Haifa, 3200003, Israel.,Technion Integrated Cancer Center, The Ruth and Bruce Rappaport Faculty of Medicine, 1-Efron St. Bat Galim, Haifa, 3525433, Israel
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59
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Veselova MA, Plyuta VA, Khmel IA. Volatile Compounds of Bacterial Origin: Structure, Biosynthesis, and Biological Activity. Microbiology (Reading) 2019. [DOI: 10.1134/s0026261719030160] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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60
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Kramshøj M, Albers CN, Svendsen SH, Björkman MP, Lindwall F, Björk RG, Rinnan R. Volatile emissions from thawing permafrost soils are influenced by meltwater drainage conditions. GLOBAL CHANGE BIOLOGY 2019; 25:1704-1716. [PMID: 30806027 DOI: 10.1111/gcb.14582] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
Vast amounts of carbon are bound in both active layer and permafrost soils in the Arctic. As a consequence of climate warming, the depth of the active layer is increasing in size and permafrost soils are thawing. We hypothesize that pulses of biogenic volatile organic compounds are released from the near-surface active layer during spring, and during late summer season from thawing permafrost, while the subsequent biogeochemical processes occurring in thawed soils also lead to emissions. Biogenic volatile organic compounds are reactive gases that have both negative and positive climate forcing impacts when introduced to the Arctic atmosphere, and the knowledge of their emission magnitude and pattern is necessary to construct reliable climate models. However, it is unclear how different ecosystems and environmental factors such as drainage conditions upon permafrost thaw affect the emission and compound composition. Here we show that incubations of frozen B horizon of the active layer and permafrost soils collected from a High Arctic heath and fen release a range of biogenic volatile organic compounds upon thaw and during subsequent incubation experiments at temperatures of 10°C and 20°C. Meltwater drainage in the fen soils increased emission rates nine times, while having no effect in the drier heath soils. Emissions generally increased with temperature, and emission profiles for the fen soils were dominated by benzenoids and alkanes, while benzenoids, ketones, and alcohols dominated in heath soils. Our results emphasize that future changes affecting the drainage conditions of the Arctic tundra will have a large influence on volatile emissions from thawing permafrost soils - particularly in wetland/fen areas.
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Affiliation(s)
- Magnus Kramshøj
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Christian N Albers
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark
| | - Sarah H Svendsen
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Mats P Björkman
- Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Frida Lindwall
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Robert G Björk
- Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
| | - Riikka Rinnan
- Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
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Interspecies Social Spreading: Interaction between Two Sessile Soil Bacteria Leads to Emergence of Surface Motility. mSphere 2019; 4:4/1/e00696-18. [PMID: 30700513 PMCID: PMC6354810 DOI: 10.1128/msphere.00696-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The wealth of studies on microbial communities has revealed the complexity and dynamics of the composition of communities in many ecological settings. Fewer studies probe the functional interactions of the community members. Function of the community as a whole may not be fully revealed by characterizing the individuals. In our two-species model community, we find an emergent trait resulting from the interaction of the soil bacteria Pseudomonas fluorescens Pf0-1 and Pedobacter sp. V48. Observation of emergent traits suggests there may be many functions of a community that are not predicted based on a priori knowledge of the community members. These types of studies will provide a more holistic understanding of microbial communities, allowing us to connect information about community composition with behaviors determined by interspecific interactions. These studies increase our ability to understand communities, such as the soil microbiome, plant-root microbiome, and human gut microbiome, with the final goal of being able to manipulate and rationally improve these communities. Bacteria often live in complex communities in which they interact with other organisms. Consideration of the social environment of bacteria can reveal emergent traits and behaviors that would be overlooked by studying bacteria in isolation. Here we characterize a social trait which emerges upon interaction between the distantly related soil bacteria Pseudomonas fluorescens Pf0-1 and Pedobacter sp. strain V48. On hard agar, which is not permissive for motility of the monoculture of either species, coculture reveals an emergent phenotype that we term “interspecies social spreading,” where the mixed colony spreads across the hard surface. We show that initiation of social spreading requires close association between the two species of bacteria. Both species remain associated throughout the spreading colony, with reproducible and nonhomogenous patterns of distribution. The nutritional environment influences social spreading: no social behavior is observed under high-nutrient conditions, but low-nutrient conditions are insufficient to promote social spreading without high salt concentrations. This simple two-species consortium is a tractable model system that will facilitate mechanistic investigations of interspecies interactions and provide insight into emergent properties of interacting species. These studies will contribute to the broader knowledge of how bacterial interactions influence the functions of communities they inhabit. IMPORTANCE The wealth of studies on microbial communities has revealed the complexity and dynamics of the composition of communities in many ecological settings. Fewer studies probe the functional interactions of the community members. Function of the community as a whole may not be fully revealed by characterizing the individuals. In our two-species model community, we find an emergent trait resulting from the interaction of the soil bacteria Pseudomonas fluorescens Pf0-1 and Pedobacter sp. V48. Observation of emergent traits suggests there may be many functions of a community that are not predicted based on a priori knowledge of the community members. These types of studies will provide a more holistic understanding of microbial communities, allowing us to connect information about community composition with behaviors determined by interspecific interactions. These studies increase our ability to understand communities, such as the soil microbiome, plant-root microbiome, and human gut microbiome, with the final goal of being able to manipulate and rationally improve these communities.
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62
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Volatile organic compounds (VOCs) produced by biocontrol yeasts. Food Microbiol 2019; 82:70-74. [PMID: 31027821 DOI: 10.1016/j.fm.2019.01.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 07/24/2018] [Accepted: 01/17/2019] [Indexed: 11/23/2022]
Abstract
The Volatile organic compounds (VOCs) produced by biocontrol yeast strains which belong to the Wickerhamomyces anomalus, Metschnikowia pulcherrima, Aureobasidium pullulans and Saccharomyces cerevisiae species were identified by solid phase microextraction (SPME) coupled with Gas Chromatography-Mass Spectrometry (GC-MS). Alcohols (ethyl alcohol, 3-methyl-1-butanol and phenylethyl alcohol) and esters (ethyl acetate and isoamyl acetate) were found to be the main VOCs emitted by the yeast strains, which had different production rate over a 16-day period. In addition, the tested yeast strains showed a remarkable ability to consume oxygen and to produce high percentages of carbon dioxide over a 5 days incubation period in a model system. The yeast strains, which were proven to very efficiently suppress in vivo the growth of postharvest fungal by VOCs, also quickly produced high percentages of ethyl acetate and carbon dioxide. . For all these reasons, we believe that the level of yeast biocontrol efficacy through the production of volatiles could be the result of a synergistic effect between VOCs and carbon dioxide in the packaging environment.
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63
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Interspecific formation of the antimicrobial volatile schleiferon. Sci Rep 2018; 8:16852. [PMID: 30442919 PMCID: PMC6237861 DOI: 10.1038/s41598-018-35341-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 11/05/2018] [Indexed: 01/06/2023] Open
Abstract
Microorganisms release a plethora of volatile secondary metabolites. Up to now, it has been widely accepted that these volatile organic compounds are produced and emitted as a final product by a single organism e.g. a bacterial cell. We questioned this commonly assumed perspective and hypothesized that in diversely colonized microbial communities, bacterial cells can passively interact by emitting precursors which non-enzymatically react to form the active final compound. This hypothesis was inspired by the discovery of the bacterial metabolite schleiferon A. This bactericidal volatile compound is formed by a non-enzymatic reaction between acetoin and 2-phenylethylamine. Both precursors are released by Staphylococcus schleiferi cells. In order to provide evidence for our hypothesis that these precursors could also be released by bacterial cells of different species, we simultaneously but separately cultivated Serratia plymuthica 4Rx13 and Staphylococcus delphini 20771 which held responsible for only one precursor necessary for schleiferon A formation, respectively. By mixing their headspace, we demonstrated that these two species were able to deliver the active principle schleiferon A. Such a joint formation of a volatile secondary metabolite by different bacterial species has not been described yet. This highlights a new aspect of interpreting multispecies interactions in microbial communities as not only direct interactions between species might determine and influence the dynamics of the community. Events outside the cell could lead to the appearance of new compounds which could possess new community shaping properties.
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Cofer TM, Seidl-Adams I, Tumlinson JH. From Acetoin to ( Z)-3-Hexen-1-ol: The Diversity of Volatile Organic Compounds that Induce Plant Responses. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:11197-11208. [PMID: 30293420 DOI: 10.1021/acs.jafc.8b03010] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Evidence that plants can respond to volatile organic compounds (VOCs) was first presented 35 years ago. Since then, over 40 VOCs have been found to induce plant responses. These include VOCs that are produced not only by plants but also by microbes and insects. Here, we summarize what is known about how these VOCs are produced and how plants detect and respond to them. In doing so, we highlight notable observations we believe are worth greater consideration. For example, the VOCs that induce plant responses appear to have little in common. They are derived from many different biosynthetic pathways and have few distinguishing chemical or structural features. Likewise, plants appear to use several mechanisms to detect VOCs rather than a single dedicated "olfactory" system. Considering these observations, we advocate for more discovery-oriented experiments and propose that future research take a fresh look at the ways plants detect and respond to VOCs.
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Affiliation(s)
- Tristan M Cofer
- Center for Chemical Ecology, Department of Entomology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Irmgard Seidl-Adams
- Center for Chemical Ecology, Department of Entomology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - James H Tumlinson
- Center for Chemical Ecology, Department of Entomology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
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65
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Hayden HL, Savin KW, Wadeson J, Gupta VVSR, Mele PM. Comparative Metatranscriptomics of Wheat Rhizosphere Microbiomes in Disease Suppressive and Non-suppressive Soils for Rhizoctonia solani AG8. Front Microbiol 2018; 9:859. [PMID: 29780371 PMCID: PMC5945926 DOI: 10.3389/fmicb.2018.00859] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 04/13/2018] [Indexed: 11/29/2022] Open
Abstract
The soilborne fungus Rhizoctonia solani anastomosis group (AG) 8 is a major pathogen of grain crops resulting in substantial production losses. In the absence of resistant cultivars of wheat or barley, a sustainable and enduring method for disease control may lie in the enhancement of biological disease suppression. Evidence of effective biological control of R. solani AG8 through disease suppression has been well documented at our study site in Avon, South Australia. A comparative metatranscriptomic approach was applied to assess the taxonomic and functional characteristics of the rhizosphere microbiome of wheat plants grown in adjacent fields which are suppressive and non-suppressive to the plant pathogen R. solani AG8. Analysis of 12 rhizosphere metatranscriptomes (six per field) was undertaken using two bioinformatic approaches involving unassembled and assembled reads. Differential expression analysis showed the dominant taxa in the rhizosphere based on mRNA annotation were Arthrobacter spp. and Pseudomonas spp. for non-suppressive samples and Stenotrophomonas spp. and Buttiauxella spp. for the suppressive samples. The assembled metatranscriptome analysis identified more differentially expressed genes than the unassembled analysis in the comparison of suppressive and non-suppressive samples. Suppressive samples showed greater expression of a polyketide cyclase, a terpenoid biosynthesis backbone gene (dxs) and many cold shock proteins (csp). Non-suppressive samples were characterised by greater expression of antibiotic genes such as non-heme chloroperoxidase (cpo) which is involved in pyrrolnitrin synthesis, and phenazine biosynthesis family protein F (phzF) and its transcriptional activator protein (phzR). A large number of genes involved in detoxifying reactive oxygen species (ROS) and superoxide radicals (sod, cat, ahp, bcp, gpx1, trx) were also expressed in the non-suppressive rhizosphere samples most likely in response to the infection of wheat roots by R. solani AG8. Together these results provide new insight into microbial gene expression in the rhizosphere of wheat in soils suppressive and non-suppressive to R. solani AG8. The approach taken and the genes involved in these functions provide direction for future studies to determine more precisely the molecular interplay of plant-microbe-pathogen interactions with the ultimate goal of the development of management options that promote beneficial rhizosphere microflora to reduce R. solani AG8 infection of crops.
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Affiliation(s)
- Helen L Hayden
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, AgriBio, Bundoora, VIC, Australia
| | - Keith W Savin
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, AgriBio, Bundoora, VIC, Australia
| | - Jenny Wadeson
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, AgriBio, Bundoora, VIC, Australia
| | - Vadakattu V S R Gupta
- CSIRO Agriculture and Food, Glen Osmond, SA, Australia.,College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Pauline M Mele
- Department of Economic Development, Jobs, Transport and Resources, Agriculture Victoria Research, AgriBio, Bundoora, VIC, Australia.,School of Applied Systems Biology, La Trobe University, Melbourne, VIC, Australia
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66
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Gaisl T, Bregy L, Stebler N, Gaugg MT, Bruderer T, García-Gómez D, Moeller A, Singer F, Schwarz EI, Benden C, M-L Sinues P, Zenobi R, Kohler M. Real-time exhaled breath analysis in patients with cystic fibrosis and controls. J Breath Res 2018; 12:036013. [DOI: 10.1088/1752-7163/aab7fd] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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67
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Avalos M, van Wezel GP, Raaijmakers JM, Garbeva P. Healthy scents: microbial volatiles as new frontier in antibiotic research? Curr Opin Microbiol 2018; 45:84-91. [PMID: 29544125 DOI: 10.1016/j.mib.2018.02.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 02/27/2018] [Indexed: 10/17/2022]
Abstract
Microorganisms represent a large and still resourceful pool for the discovery of novel compounds to combat antibiotic resistance in human and animal pathogens. The ability of microorganisms to produce structurally diverse volatile compounds has been known for decades, yet their biological functions and antimicrobial activities have only recently attracted attention. Various studies revealed that microbial volatiles can act as infochemicals in long-distance cross-kingdom communication as well as antimicrobials in competition and predation. Here, we review recent insights into the natural functions and modes of action of microbial volatiles and discuss their potential as a new class of antimicrobials and modulators of antibiotic resistance.
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Affiliation(s)
- Mariana Avalos
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Gilles P van Wezel
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands; Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands
| | - Jos M Raaijmakers
- Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands; Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands
| | - Paolina Garbeva
- Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands.
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68
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Schulz-Bohm K, Gerards S, Hundscheid M, Melenhorst J, de Boer W, Garbeva P. Calling from distance: attraction of soil bacteria by plant root volatiles. ISME JOURNAL 2018; 12:1252-1262. [PMID: 29358736 DOI: 10.1038/s41396-017-0035-3] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/25/2017] [Accepted: 11/28/2017] [Indexed: 02/05/2023]
Abstract
Plants release a wide set of secondary metabolites including volatile organic compounds (VOCs). Many of those compounds are considered to function as defense against herbivory, pests, and pathogens. However, little knowledge exists about the role of belowground plant VOCs for attracting beneficial soil microorganisms. We developed an olfactometer system to test the attraction of soil bacteria by VOCs emitted by Carex arenaria roots. Moreover, we tested whether infection of C. arenaria with the fungal pathogen Fusarium culmorum modifies the VOCs profile and bacterial attraction. The results revealed that migration of distant bacteria in soil towards roots can be stimulated by plant VOCs. Upon fungal infection, the blend of root VOCs changed and specific bacteria with antifungal properties were attracted. Tests with various pure VOCs indicated that those compounds can diffuse over long distance but with different diffusion abilities. Overall, this work highlights the importance of plant VOCs in belowground long-distance plant-microbe interactions.
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Affiliation(s)
- Kristin Schulz-Bohm
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6700 AB, Wageningen, The Netherlands.
| | - Saskia Gerards
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6700 AB, Wageningen, The Netherlands
| | - Maria Hundscheid
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6700 AB, Wageningen, The Netherlands
| | - Jasper Melenhorst
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6700 AB, Wageningen, The Netherlands
| | - Wietse de Boer
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6700 AB, Wageningen, The Netherlands.,Department of Soil Quality, Wageningen University, 6708 PB, Wageningen, The Netherlands
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), 6700 AB, Wageningen, The Netherlands.
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69
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Schulz-Bohm K, Martín-Sánchez L, Garbeva P. Microbial Volatiles: Small Molecules with an Important Role in Intra- and Inter-Kingdom Interactions. Front Microbiol 2017; 8:2484. [PMID: 29312193 PMCID: PMC5733050 DOI: 10.3389/fmicb.2017.02484] [Citation(s) in RCA: 203] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/29/2017] [Indexed: 01/17/2023] Open
Abstract
During the last decades, research on the function of volatile organic compounds focused primarily on the interactions between plants and insects. However, microorganisms can also release a plethora of volatiles and it appears that microbial volatile organic compounds (mVOCs) can play an important role in intra- and inter-kingdom interactions. So far, most studies are focused on aboveground volatile-mediated interactions and much less information is available about the function of volatiles belowground. This minireview summarizes the current knowledge on the biological functions of mVOCs with the focus on mVOCs-mediated interactions belowground. We pinpointed mVOCs involved in microbe-microbe and microbe–plant interactions, and highlighted the ecological importance of microbial terpenes as a largely underexplored group of mVOCs. We indicated challenges in studying belowground mVOCs-mediated interactions and opportunities for further studies and practical applications.
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Affiliation(s)
- Kristin Schulz-Bohm
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands
| | - Lara Martín-Sánchez
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands
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70
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Yuan J, Zhao M, Li R, Huang Q, Raza W, Rensing C, Shen Q. Microbial volatile compounds alter the soil microbial community. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:22485-22493. [PMID: 28803260 DOI: 10.1007/s11356-017-9839-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 07/26/2017] [Indexed: 06/07/2023]
Abstract
Volatile organic compounds (VOCs) from soil bacteria are likely to have an important role in the interactions among soil microorganisms. However, their effects on the soil microbial community have not been extensively studied. In this study, the effect of bacterial VOCs generated by growing Bacillus amyloliquefaciens NJN-6 on modified MS medium on soil microbial community was evaluated. B. amyloliquefaciens NJN-6 was able to produce 48 volatile compounds as determined by solid-phase microextraction-GC/MS. MiSeq sequencing data showed that bacterial VOCs could alter the composition of both soil bacterial and soil fungal communities and could decrease the alpha-diversity of the soil microbial community. Taxonomic analysis revealed that bacterial VOCs significantly increased the relative abundance of Proteobacteria, Bacteroidetes, and Firmicutes. Moreover, bacterial VOCs significantly increased the relative abundance of Ascomycota. The qPCR data showed that bacterial VOCs of strain NJN-6 decreased the soil fungal biomass and increased the soil bacterial biomass. Further evaluation of the effect of bacterial VOCs on functional genes revealed that VOCs could reduce the copies of nifH, nirS, and a gene encoding nonribosomal peptide synthase, while increasing the copy number of the ammonium-oxidizing bacteria gene. The effect on gene encoding polyketide synthase was insignificant. Results from this study indicated that bacterial VOCs could influence the soil microbial community as well as functional gene abundance.
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Affiliation(s)
- Jun Yuan
- Jiangsu Provincial Key Laboratory of Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Organic Solid Waste Utilization, and National Engineering Research Center for Organic-based Fertilizer, Nanjing Agricultural University, Nanjing, 210095, China
| | - Mengli Zhao
- Jiangsu Provincial Key Laboratory of Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Organic Solid Waste Utilization, and National Engineering Research Center for Organic-based Fertilizer, Nanjing Agricultural University, Nanjing, 210095, China
| | - Rong Li
- Jiangsu Provincial Key Laboratory of Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Organic Solid Waste Utilization, and National Engineering Research Center for Organic-based Fertilizer, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qiwei Huang
- Jiangsu Provincial Key Laboratory of Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Organic Solid Waste Utilization, and National Engineering Research Center for Organic-based Fertilizer, Nanjing Agricultural University, Nanjing, 210095, China
| | - Waseem Raza
- Jiangsu Provincial Key Laboratory of Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Organic Solid Waste Utilization, and National Engineering Research Center for Organic-based Fertilizer, Nanjing Agricultural University, Nanjing, 210095, China
| | - Christopher Rensing
- Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and the Environment, Fujian Agriculture & Forestry University, Fuzhou, 350002, China
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
- J. Craig Venter Institute, La Jolla, CA, USA
| | - Qirong Shen
- Jiangsu Provincial Key Laboratory of Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Organic Solid Waste Utilization, and National Engineering Research Center for Organic-based Fertilizer, Nanjing Agricultural University, Nanjing, 210095, China.
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71
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Bailly A, Weisskopf L. Mining the Volatilomes of Plant-Associated Microbiota for New Biocontrol Solutions. Front Microbiol 2017; 8:1638. [PMID: 28890716 PMCID: PMC5574903 DOI: 10.3389/fmicb.2017.01638] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 08/14/2017] [Indexed: 12/13/2022] Open
Abstract
Microbial lifeforms associated with land plants represent a rich source for crop growth- and health-promoting microorganisms and biocontrol agents. Volatile organic compounds (VOCs) produced by the plant microbiota have been demonstrated to elicit plant defenses and inhibit the growth and development of numerous plant pathogens. Therefore, these molecules are prospective alternatives to synthetic pesticides and the determination of their bioactivities against plant threats could contribute to the development of control strategies for sustainable agriculture. In our previous study we investigated the inhibitory impact of volatiles emitted by Pseudomonas species isolated from a potato field against the late blight-causing agent Phytophthora infestans. Besides the well-documented emission of hydrogen cyanide, other Pseudomonas VOCs impeded P. infestans mycelial growth and sporangia germination. Current advances in the field support the emerging concept that the microbial volatilome contains unexploited, eco-friendly chemical resources that could help select for efficient biocontrol strategies and lead to a greener chemical disease management in the field.
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Affiliation(s)
- Aurélien Bailly
- Department of Plant and Microbial Biology, University of ZurichZurich, Switzerland.,Agroscope, Institute for Sustainability SciencesZurich, Switzerland
| | - Laure Weisskopf
- Agroscope, Institute for Sustainability SciencesZurich, Switzerland.,Department of Biology, University of FribourgFribourg, Switzerland
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72
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Brader G, Compant S, Vescio K, Mitter B, Trognitz F, Ma LJ, Sessitsch A. Ecology and Genomic Insights into Plant-Pathogenic and Plant-Nonpathogenic Endophytes. ANNUAL REVIEW OF PHYTOPATHOLOGY 2017; 55:61-83. [PMID: 28489497 DOI: 10.1146/annurev-phyto-080516-035641] [Citation(s) in RCA: 197] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Plants are colonized on their surfaces and in the rhizosphere and phyllosphere by a multitude of different microorganisms and are inhabited internally by endophytes. Most endophytes act as commensals without any known effect on their plant host, but multiple bacteria and fungi establish a mutualistic relationship with plants, and some act as pathogens. The outcome of these plant-microbe interactions depends on biotic and abiotic environmental factors and on the genotype of the host and the interacting microorganism. In addition, endophytic microbiota and the manifold interactions between members, including pathogens, have a profound influence on the function of the system plant and the development of pathobiomes. In this review, we elaborate on the differences and similarities between nonpathogenic and pathogenic endophytes in terms of host plant response, colonization strategy, and genome content. We furthermore discuss environmental effects and biotic interactions within plant microbiota that influence pathogenesis and the pathobiome.
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Affiliation(s)
- Günter Brader
- Center for Health and Bioresources, Bioresources Unit, Austrian Institute of Technology (AIT), 3430 Tulln, Austria
| | - Stéphane Compant
- Center for Health and Bioresources, Bioresources Unit, Austrian Institute of Technology (AIT), 3430 Tulln, Austria
| | - Kathryn Vescio
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003;
| | - Birgit Mitter
- Center for Health and Bioresources, Bioresources Unit, Austrian Institute of Technology (AIT), 3430 Tulln, Austria
| | - Friederike Trognitz
- Center for Health and Bioresources, Bioresources Unit, Austrian Institute of Technology (AIT), 3430 Tulln, Austria
| | - Li-Jun Ma
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003;
| | - Angela Sessitsch
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003;
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73
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Tyc O, de Jager VCL, van den Berg M, Gerards S, Janssens TKS, Zaagman N, Kai M, Svatos A, Zweers H, Hordijk C, Besselink H, de Boer W, Garbeva P. Exploring bacterial interspecific interactions for discovery of novel antimicrobial compounds. Microb Biotechnol 2017; 10:910-925. [PMID: 28557379 PMCID: PMC5481530 DOI: 10.1111/1751-7915.12735] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 04/26/2017] [Accepted: 04/28/2017] [Indexed: 11/29/2022] Open
Abstract
Recent studies indicated that the production of secondary metabolites by soil bacteria can be triggered by interspecific interactions. However, little is known to date about interspecific interactions between Gram-positive and Gram-negative bacteria. In this study, we aimed to understand how the interspecific interaction between the Gram-positive Paenibacillus sp. AD87 and the Gram-negative Burkholderia sp. AD24 affects the fitness, gene expression and the production of soluble and volatile secondary metabolites of both bacteria. To obtain better insight into this interaction, transcriptome and metabolome analyses were performed. Our results revealed that the interaction between the two bacteria affected their fitness, gene expression and the production of secondary metabolites. During interaction, the growth of Paenibacillus was not affected, whereas the growth of Burkholderia was inhibited at 48 and 72 h. Transcriptome analysis revealed that the interaction between Burkholderia and Paenibacillus caused significant transcriptional changes in both bacteria as compared to the monocultures. The metabolomic analysis revealed that the interaction increased the production of specific volatile and soluble antimicrobial compounds such as 2,5-bis(1-methylethyl)-pyrazine and an unknown Pederin-like compound. The pyrazine volatile compound produced by Paenibacillus was subjected to bioassays and showed strong inhibitory activity against Burkholderia and a range of plant and human pathogens. Moreover, strong additive antimicrobial effects were observed when soluble extracts from the interacting bacteria were combined with the pure 2,5-bis(1-methylethyl)-pyrazine. The results obtained in this study highlight the importance to explore bacterial interspecific interactions to discover novel secondary metabolites and to perform simultaneously metabolomics of both, soluble and volatile compounds.
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Affiliation(s)
- Olaf Tyc
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB, Wageningen, The Netherlands
| | - Victor C L de Jager
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB, Wageningen, The Netherlands
| | - Marlies van den Berg
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB, Wageningen, The Netherlands
| | - Saskia Gerards
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB, Wageningen, The Netherlands
| | | | - Niels Zaagman
- MicroLife Solutions B.V., Science Park 406, 1098 XH, Amsterdam, The Netherlands
| | - Marco Kai
- Mass Spectrometry Research Group, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, D-07745, Jena, Germany
| | - Ales Svatos
- Mass Spectrometry Research Group, Max Planck Institute for Chemical Ecology, Hans-Knoell-Str. 8, D-07745, Jena, Germany
| | - Hans Zweers
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB, Wageningen, The Netherlands
| | - Cornelis Hordijk
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB, Wageningen, The Netherlands
| | - Harrie Besselink
- BioDetection Systems B.V., Science Park 406, 1098 XH, Amsterdam, The Netherlands
| | - Wietse de Boer
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB, Wageningen, The Netherlands
- Department of Soil Quality, Wageningen University and Research Centre (WUR), PO BOX 47, 6700 AA, Wageningen, The Netherlands
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), PO BOX 50, 6700 AB, Wageningen, The Netherlands
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74
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Fungal volatile compounds induce production of the secondary metabolite Sodorifen in Serratia plymuthica PRI-2C. Sci Rep 2017; 7:862. [PMID: 28408760 PMCID: PMC5429845 DOI: 10.1038/s41598-017-00893-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/16/2017] [Indexed: 01/24/2023] Open
Abstract
The ability of bacteria and fungi to communicate with each other is a remarkable aspect of the microbial world. It is recognized that volatile organic compounds (VOCs) act as communication signals, however the molecular responses by bacteria to fungal VOCs remain unknown. Here we perform transcriptomics and proteomics analyses of Serratia plymuthica PRI-2C exposed to VOCs emitted by the fungal pathogen Fusarium culmorum. We find that the bacterium responds to fungal VOCs with changes in gene and protein expression related to motility, signal transduction, energy metabolism, cell envelope biogenesis, and secondary metabolite production. Metabolomic analysis of the bacterium exposed to the fungal VOCs, gene cluster comparison, and heterologous co-expression of a terpene synthase and a methyltransferase revealed the production of the unusual terpene sodorifen in response to fungal VOCs. These results strongly suggest that VOCs are not only a metabolic waste but important compounds in the long-distance communication between fungi and bacteria.
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75
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The Ecological Role of Volatile and Soluble Secondary Metabolites Produced by Soil Bacteria. Trends Microbiol 2017; 25:280-292. [DOI: 10.1016/j.tim.2016.12.002] [Citation(s) in RCA: 240] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 11/15/2016] [Accepted: 12/05/2016] [Indexed: 01/11/2023]
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76
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Ossowicki A, Jafra S, Garbeva P. The antimicrobial volatile power of the rhizospheric isolate Pseudomonas donghuensis P482. PLoS One 2017; 12:e0174362. [PMID: 28358818 PMCID: PMC5373542 DOI: 10.1371/journal.pone.0174362] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/07/2017] [Indexed: 11/19/2022] Open
Abstract
Soil and rhizosphere bacteria produce an array of secondary metabolites including a wide range of volatile organic compounds (VOCs). These compounds play an important role in the long-distance interactions and communication between (micro)organisms. Furthermore, bacterial VOCs are involved in plant pathogens inhibition and induction of soil fungistasis and suppressivenes. In the present study, we analysed the volatile blend emitted by the rhizospheric isolate Pseudomonas donghuensis P482 and evaluated the volatile effect on the plant pathogenic fungi and bacteria as well as one oomycete. Moreover, we investigated the role of the GacS/GacA system on VOCs production in P. donghuensis P482. The results obtained demonstrated that VOCs emitted by P. donghuensis P482 have strong antifungal and antioomycete, but not antibacterial activity. The production of certain volatiles such as dimethyl sulfide, S-methyl thioacetate, methyl thiocyanate, dimethyl trisulfide, 1-undecan and HCN is depended on the GacS/GacA two-component regulatory system. Apparently, these compounds play an important role in the pathogens suppression as the gacA mutant entirely lost the ability to inhibit via volatiles the growth of tested plant pathogens.
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Affiliation(s)
- Adam Ossowicki
- Laboratory of Biological Plant Protection, Department of Biotechnology, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, Gdansk, Poland
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Sylwia Jafra
- Laboratory of Biological Plant Protection, Department of Biotechnology, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, Gdansk, Poland
- * E-mail: (PG); (SJ)
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
- * E-mail: (PG); (SJ)
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77
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Growth-altering microbial interactions are responsive to chemical context. PLoS One 2017; 12:e0164919. [PMID: 28319121 PMCID: PMC5358735 DOI: 10.1371/journal.pone.0164919] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 02/27/2017] [Indexed: 11/20/2022] Open
Abstract
Microbial interactions are ubiquitous in nature, and are equally as relevant to human wellbeing as the identities of the interacting microbes. However, microbial interactions are difficult to measure and characterize. Furthermore, there is growing evidence that they are not fixed, but dependent on environmental context. We present a novel workflow for inferring microbial interactions that integrates semi-automated image analysis with a colony stamping mechanism, with the overall effect of improving throughput and reproducibility of colony interaction assays. We apply our approach to infer interactions among bacterial species associated with the normal lung microbiome, and how those interactions are altered by the presence of benzo[a]pyrene, a carcinogenic compound found in cigarettes. We found that the presence of this single compound changed the interaction network, demonstrating that microbial interactions are indeed dynamic and responsive to local chemical context.
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78
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Westhoff S, van Wezel GP, Rozen DE. Distance-dependent danger responses in bacteria. Curr Opin Microbiol 2017; 36:95-101. [PMID: 28258981 DOI: 10.1016/j.mib.2017.02.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 01/27/2017] [Accepted: 02/01/2017] [Indexed: 12/23/2022]
Abstract
The last decade has seen a resurgence in our understanding of the diverse mechanisms that bacteria use to kill one another. We are also beginning to uncover the responses and countermeasures that bacteria use when faced with specific threats or general cues of potential danger from bacterial competitors. In this Perspective, we propose that diverse offensive and defensive responses in bacteria have evolved to offset dangers detected at different distances. Thus, while volatile organic compounds provide bacterial cells with a warning at the greatest distance, diffusible compounds like antibiotics or contact mediated killing systems, indicate a more pressing danger warranting highly-specific responses. In the competitive environments in which bacteria live, it is crucial that cells are able to detect real or potential dangers from other cells. By utilizing mechanisms of detection that can infer the distance from danger, bacteria can fine-tune aggressive interactions so that they can optimally respond to threats occurring with distinct levels of risk.
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Affiliation(s)
- Sanne Westhoff
- Institute of Biology, Leiden University, Sylvius Laboratory, Sylviusweg 72, 2300 BE Leiden, The Netherlands.
| | - Gilles P van Wezel
- Institute of Biology, Leiden University, Sylvius Laboratory, Sylviusweg 72, 2300 BE Leiden, The Netherlands
| | - Daniel E Rozen
- Institute of Biology, Leiden University, Sylvius Laboratory, Sylviusweg 72, 2300 BE Leiden, The Netherlands
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79
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Hacquard S. Commentary: Microbial Small Talk: Volatiles in Fungal-Bacterial Interactions. Front Microbiol 2017; 8:1. [PMID: 28197127 PMCID: PMC5281593 DOI: 10.3389/fmicb.2017.00001] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 01/03/2017] [Indexed: 11/29/2022] Open
Affiliation(s)
- Stéphane Hacquard
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research Cologne, Germany
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80
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Grady EN, MacDonald J, Liu L, Richman A, Yuan ZC. Current knowledge and perspectives of Paenibacillus: a review. Microb Cell Fact 2016; 15:203. [PMID: 27905924 PMCID: PMC5134293 DOI: 10.1186/s12934-016-0603-7] [Citation(s) in RCA: 444] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 11/24/2016] [Indexed: 12/11/2022] Open
Abstract
Isolated from a wide range of sources, the genus Paenibacillus comprises bacterial species relevant to humans, animals, plants, and the environment. Many Paenibacillus species can promote crop growth directly via biological nitrogen fixation, phosphate solubilization, production of the phytohormone indole-3-acetic acid (IAA), and release of siderophores that enable iron acquisition. They can also offer protection against insect herbivores and phytopathogens, including bacteria, fungi, nematodes, and viruses. This is accomplished by the production of a variety of antimicrobials and insecticides, and by triggering a hypersensitive defensive response of the plant, known as induced systemic resistance (ISR). Paenibacillus-derived antimicrobials also have applications in medicine, including polymyxins and fusaricidins, which are nonribosomal lipopeptides first isolated from strains of Paenibacillus polymyxa. Other useful molecules include exo-polysaccharides (EPS) and enzymes such as amylases, cellulases, hemicellulases, lipases, pectinases, oxygenases, dehydrogenases, lignin-modifying enzymes, and mutanases, which may have applications for detergents, food and feed, textiles, paper, biofuel, and healthcare. On the negative side, Paenibacillus larvae is the causative agent of American Foulbrood, a lethal disease of honeybees, while a variety of species are opportunistic infectors of humans, and others cause spoilage of pasteurized dairy products. This broad review summarizes the major positive and negative impacts of Paenibacillus: its realised and prospective contributions to agriculture, medicine, process manufacturing, and bioremediation, as well as its impacts due to pathogenicity and food spoilage. This review also includes detailed information in Additional files 1, 2, 3 for major known Paenibacillus species with their locations of isolation, genome sequencing projects, patents, and industrially significant compounds and enzymes. Paenibacillus will, over time, play increasingly important roles in sustainable agriculture and industrial biotechnology.
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Affiliation(s)
- Elliot Nicholas Grady
- London Research and Development Centre, Agriculture & Agri-Food Canada, 1391 Sandford Street, London, ON N5V 4T3 Canada
| | - Jacqueline MacDonald
- Department of Microbiology & Immunology, Schulich School of Medicine & Dentistry, University of Western Ontario, Dental Science Building Rm. 3014, London, ON N6A 5C1 Canada
| | - Linda Liu
- London Research and Development Centre, Agriculture & Agri-Food Canada, 1391 Sandford Street, London, ON N5V 4T3 Canada
| | - Alex Richman
- London Research and Development Centre, Agriculture & Agri-Food Canada, 1391 Sandford Street, London, ON N5V 4T3 Canada
| | - Ze-Chun Yuan
- London Research and Development Centre, Agriculture & Agri-Food Canada, 1391 Sandford Street, London, ON N5V 4T3 Canada
- Department of Microbiology & Immunology, Schulich School of Medicine & Dentistry, University of Western Ontario, Dental Science Building Rm. 3014, London, ON N6A 5C1 Canada
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81
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Cheng X, Cordovez V, Etalo DW, van der Voort M, Raaijmakers JM. Role of the GacS Sensor Kinase in the Regulation of Volatile Production by Plant Growth-Promoting Pseudomonas fluorescens SBW25. FRONTIERS IN PLANT SCIENCE 2016; 7:1706. [PMID: 27917180 PMCID: PMC5114270 DOI: 10.3389/fpls.2016.01706] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 10/31/2016] [Indexed: 05/25/2023]
Abstract
In plant-associated Pseudomonas species, the production of several secondary metabolites and exoenzymes is regulated by the GacS/GacA two-component regulatory system (the Gac-system). Here, we investigated if a mutation in the GacS sensor kinase affects the production of volatile organic compounds (VOCs) in P. fluorescens SBW25 (Pf.SBW25) and how this impacts on VOCs-mediated growth promotion and induced systemic resistance of Arabidopsis and tobacco. A total of 205 VOCs were detected by Gas Chromatography Mass Spectrometry for Pf. SBW25 and the gacS-mutant grown on two different media for 3 and 6 days. Discriminant function analysis followed by hierarchical clustering revealed 24 VOCs that were significantly different in their abundance between Pf.SBW25 and the gacS-mutant, which included three acyclic alkenes (3-nonene, 4-undecyne, 1-undecene). These alkenes were significantly reduced by the gacS mutation independently of the growth media and of the incubation time. For Arabidopsis, both Pf.SBW25 and the gacS-mutant enhanced, via VOCs, root and shoot biomass, induced systemic resistance against leaf infections by P. syringae and rhizosphere acidification to the same extent. For tobacco, however, VOCs-mediated effects on shoot and root growth were significantly different between Pf.SBW25 and the gacS-mutant. While Pf.SBW25 inhibited tobacco root growth, the gacS-mutant enhanced root biomass and lateral root formation relative to the non-treated control plants. Collectively these results indicate that the sensor kinase GacS is involved in the regulation of VOCs production in Pf.SBW25, affecting plant growth in a plant species-dependent manner.
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Affiliation(s)
- Xu Cheng
- Laboratory of Phytopathology, Wageningen UniversityWageningen, Netherlands
| | - Viviane Cordovez
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands
| | - Desalegn W. Etalo
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands
| | | | - Jos M. Raaijmakers
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands
- Institute of Biology Leiden, Leiden UniversityLeiden, Netherlands
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82
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Schulz-Bohm K, Tyc O, de Boer W, Peereboom N, Debets F, Zaagman N, Janssens TKS, Garbeva P. Fungus-associated bacteriome in charge of their host behavior. Fungal Genet Biol 2016; 102:38-48. [PMID: 27486066 DOI: 10.1016/j.fgb.2016.07.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 07/19/2016] [Accepted: 07/28/2016] [Indexed: 11/18/2022]
Abstract
Bacterial-fungal interactions are widespread in nature and there is a growing number of studies reporting distinct fungus-associated bacteria. However, little is known so far about how shifts in the fungus-associated bacteriome will affect the fungal host's lifestyle. In the present study, we describe for the first time the bacterial community associated with the saprotrophic fungus Mucor hiemalis, commonly found in soil and rhizosphere. Two broad-spectrum antibiotics that strongly altered the bacterial community associated with the fungus were applied. Our results revealed that the antibiotic treatment did not significantly reduce the amount of bacteria associated to the fungus but rather changed the community composition by shifting from initially dominating Alpha-Proteobacteria to dominance of Gamma-Proteobacteria. A novel approach was applied for the isolation of fungal-associated bacteria which also revealed differences between bacterial isolates obtained from the original and the antibiotic-treated M. hiemalis. The shift in the composition of the fungal-associated bacterial community led to significantly reduced fungal growth, changes in fungal morphology, behavior and secondary-metabolites production. Furthermore, our results showed that the antibiotic-treated isolate was more attractive and susceptible to mycophagous bacteria as compared to the original isolate. Overall, our study highlights the importance of the fungus-associated bacteriome for the host's lifestyle and interactions and indicate that isolation with antibacterials is not sufficient to eradicate the associated bacteria.
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Affiliation(s)
- Kristin Schulz-Bohm
- Department Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, PO Box 50, 6700 AB Wageningen, Netherlands; Department of Soil Quality, Wageningen University & Research Centre (WUR), PO Box 47, 6700 AA Wageningen, Netherlands
| | - Olaf Tyc
- Department Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, PO Box 50, 6700 AB Wageningen, Netherlands; Department of Soil Quality, Wageningen University & Research Centre (WUR), PO Box 47, 6700 AA Wageningen, Netherlands
| | - Wietse de Boer
- Department Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, PO Box 50, 6700 AB Wageningen, Netherlands; Department of Soil Quality, Wageningen University & Research Centre (WUR), PO Box 47, 6700 AA Wageningen, Netherlands
| | - Nils Peereboom
- Department Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, PO Box 50, 6700 AB Wageningen, Netherlands; Laboratory of Genetics, Wageningen University & Research Centre (WUR), PO Box 16, 6700 AA Wageningen, Netherlands
| | - Fons Debets
- Laboratory of Genetics, Wageningen University & Research Centre (WUR), PO Box 16, 6700 AA Wageningen, Netherlands
| | - Niels Zaagman
- MicroLife Solutions b.v., Science Park 406, 1098 XH Amsterdam, Netherlands
| | | | - Paolina Garbeva
- Department Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW, PO Box 50, 6700 AB Wageningen, Netherlands.
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83
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Effect of organic fertilizers prepared from organic waste materials on the production of antibacterial volatile organic compounds by two biocontrol Bacillus amyloliquefaciens strains. J Biotechnol 2016; 227:43-53. [PMID: 27067079 DOI: 10.1016/j.jbiotec.2016.04.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 04/02/2016] [Accepted: 04/07/2016] [Indexed: 01/19/2023]
Abstract
Three organic fertilizers made of different animal and plant waste materials (BOFs) were evaluated for their effects on the production of antibacterial volatile organic compounds (VOCs) by two Bacillus amyloliquefaciens strains SQR-9 and T-5 against the tomato wilt pathogen Ralstonia solanacearum (RS). Both strains could produce VOCs that inhibited the growth and virulence traits of RS; however, in the presence of BOFs, the production of antibacterial VOCs was significantly increased. The maximum inhibition of growth and virulence traits of RS by VOCs of T-5 and SQR-9 was determined at 1.5% BOF2 and 2% BOF3, respectively. In case of strain T-5, 2-nonanone, nonanal, xylene, benzothiazole, and butylated hydroxy toluene and in case of strain SQR-9, 2-nonanone, nonanal, xylene and 2-undecanone were the main antibacterial VOCs whose production was increased in the presence of BOFs. The results of this study reveal another significance of using organic fertilizers to improve the antagonistic activity of biocontrol agents against phytopathogens.
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84
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Asari S, Matzén S, Petersen MA, Bejai S, Meijer J. Multiple effects ofBacillus amyloliquefaciensvolatile compounds: plant growth promotion and growth inhibition of phytopathogens. FEMS Microbiol Ecol 2016; 92:fiw070. [DOI: 10.1093/femsec/fiw070] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2016] [Indexed: 01/18/2023] Open
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85
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Kai M, Effmert U, Piechulla B. Bacterial-Plant-Interactions: Approaches to Unravel the Biological Function of Bacterial Volatiles in the Rhizosphere. Front Microbiol 2016; 7:108. [PMID: 26903987 PMCID: PMC4746483 DOI: 10.3389/fmicb.2016.00108] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 01/21/2016] [Indexed: 11/13/2022] Open
Abstract
Rhizobacteria produce an enormous amount of volatile compounds, however, the function of these metabolites is scarcely understood. Investigations evaluating influences on plants performed in various laboratories using individually developed experimental setups revealed different and often contradictory results, e.g., ranging from a significant plant growth promotion to a dramatic suppression of plant development. In addition to these discrepancies, these test systems neglected properties and complexity of the rhizosphere. Therefore, to pursue further investigations of the role of bacterial volatiles in this underground habitat, the applied methods have to simulate its natural characteristics as much as possible. In this review, we will describe and discuss pros and cons of currently used bioassays, give insights into rhizosphere characteristics, and suggest improvements for test systems that would consider in natura conditions and would allow gaining further knowledge of the potential function and significance of rhizobacterial volatiles in plant life.
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Affiliation(s)
- Marco Kai
- Department of Biochemistry, Institute of Biological Science, University of Rostock Rostock, Germany
| | - Uta Effmert
- Department of Biochemistry, Institute of Biological Science, University of Rostock Rostock, Germany
| | - Birgit Piechulla
- Department of Biochemistry, Institute of Biological Science, University of Rostock Rostock, Germany
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86
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Schmidt R, Etalo DW, de Jager V, Gerards S, Zweers H, de Boer W, Garbeva P. Microbial Small Talk: Volatiles in Fungal-Bacterial Interactions. Front Microbiol 2016; 6:1495. [PMID: 26779150 PMCID: PMC4700264 DOI: 10.3389/fmicb.2015.01495] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 12/11/2015] [Indexed: 01/01/2023] Open
Abstract
There is increasing evidence that volatile organic compounds (VOCs) play an important role in the interactions between fungi and bacteria, two major groups of soil inhabiting microorganisms. Yet, most of the research has been focused on effects of bacterial volatiles on suppression of plant pathogenic fungi whereas little is known about the responses of bacteria to fungal volatiles. In the current study we performed a metabolomics analysis of volatiles emitted by several fungal and oomycetal soil strains under different nutrient conditions and growth stages. The metabolomics analysis of the tested fungal and oomycetal strains revealed different volatile profiles dependent on the age of the strains and nutrient conditions. Furthermore, we screened the phenotypic responses of soil bacterial strains to volatiles emitted by fungi. Two bacteria, Collimonas pratensis Ter291 and Serratia plymuthica PRI-2C, showed significant changes in their motility, in particular to volatiles emitted by Fusarium culmorum. This fungus produced a unique volatile blend, including several terpenes. Four of these terpenes were selected for further tests to investigate if they influence bacterial motility. Indeed, these terpenes induced or reduced swimming and swarming motility of S. plymuthica PRI-2C and swarming motility of C. pratensis Ter291, partly in a concentration-dependent manner. Overall the results of this work revealed that bacteria are able to sense and respond to fungal volatiles giving further evidence to the suggested importance of volatiles as signaling molecules in fungal-bacterial interactions.
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Affiliation(s)
- Ruth Schmidt
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands
| | - Desalegn W. Etalo
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands
| | - Victor de Jager
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands
| | - Saskia Gerards
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands
| | - Hans Zweers
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands
| | - Wietse de Boer
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands
- Department of Soil Quality, Wageningen UniversityWageningen, Netherlands
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands
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87
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Calling in the Dark: The Role of Volatiles for Communication in the Rhizosphere. SIGNALING AND COMMUNICATION IN PLANTS 2016. [DOI: 10.1007/978-3-319-33498-1_8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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88
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Song C, Schmidt R, de Jager V, Krzyzanowska D, Jongedijk E, Cankar K, Beekwilder J, van Veen A, de Boer W, van Veen JA, Garbeva P. Exploring the genomic traits of fungus-feeding bacterial genus Collimonas. BMC Genomics 2015; 16:1103. [PMID: 26704531 PMCID: PMC4690342 DOI: 10.1186/s12864-015-2289-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 12/11/2015] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Collimonas is a genus belonging to the class of Betaproteobacteria and consists mostly of soil bacteria with the ability to exploit living fungi as food source (mycophagy). Collimonas strains differ in a range of activities, including swimming motility, quorum sensing, extracellular protease activity, siderophore production, and antimicrobial activities. RESULTS In order to reveal ecological traits possibly related to Collimonas lifestyle and secondary metabolites production, we performed a comparative genomics analysis based on whole-genome sequencing of six strains representing 3 recognized species. The analysis revealed that the core genome represents 43.1 to 52.7% of the genomes of the six individual strains. These include genes coding for extracellular enzymes (chitinase, peptidase, phospholipase), iron acquisition and type II secretion systems. In the variable genome, differences were found in genes coding for secondary metabolites (e.g. tripropeptin A and volatile terpenes), several unknown orphan polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS), nonribosomal peptide synthetase (NRPS) gene clusters, a new lipopeptide and type III and type VI secretion systems. Potential roles of the latter genes in the interaction with other organisms were investigated. Mutation of a gene involved in tripropeptin A biosynthesis strongly reduced the antibacterial activity against Staphylococcus aureus, while disruption of a gene involved in the biosynthesis of the new lipopeptide had a large effect on the antifungal/oomycetal activities. CONCLUSIONS Overall our results indicated that Collimonas genomes harbour many genes encoding for novel enzymes and secondary metabolites (including terpenes) important for interactions with other organisms and revealed genomic plasticity, which reflect the behaviour, antimicrobial activity and lifestylesof Collimonas spp.
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Affiliation(s)
- Chunxu Song
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Ruth Schmidt
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Victor de Jager
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Dorota Krzyzanowska
- Laboratory of Biological Plant Protection, Intercollegiate Faculty of Biotechnology UG&MUG, Kladki 24, Gdansk, 80-822, Poland.
| | - Esmer Jongedijk
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands.
| | - Katarina Cankar
- Business Unit Bioscience, Plant Research International, Wageningen University and Research Centre, Wageningen, The Netherlands.
| | - Jules Beekwilder
- Business Unit Bioscience, Plant Research International, Wageningen University and Research Centre, Wageningen, The Netherlands.
| | - Anouk van Veen
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Wietse de Boer
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Johannes A van Veen
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Paolina Garbeva
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
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89
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Audrain B, Létoffé S, Ghigo JM. Airborne Bacterial Interactions: Functions Out of Thin Air? Front Microbiol 2015; 6:1476. [PMID: 26733998 PMCID: PMC4686687 DOI: 10.3389/fmicb.2015.01476] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 12/08/2015] [Indexed: 12/23/2022] Open
Abstract
Bacteria produce and release a large diversity of small molecules including organic and inorganic volatile compounds, hereafter referred to as bacterial volatile compounds (BVCs). Whereas BVCs were often only considered as wasted metabolic by-product sometimes perceived by animal olfactory systems, it is increasingly clear that they can also mediate cross-kingdom interactions with fungi, plants and animals. Recently, in vitro studies also reported the impact of BVCs on bacterial biology through modulation of antibiotic resistance, biofilm formation and virulence. Here, we review BVCs influence on bacterial adaptation to their environment and discuss the biological relevance of recently reported inter- and intra-species bacterial interactions mediated by BVCs.
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Affiliation(s)
- Bianca Audrain
- Genetics of Biofilms Laboratory, Department of Microbiology, Institut Pasteur Paris, France
| | - Sylvie Létoffé
- Genetics of Biofilms Laboratory, Department of Microbiology, Institut Pasteur Paris, France
| | - Jean-Marc Ghigo
- Genetics of Biofilms Laboratory, Department of Microbiology, Institut Pasteur Paris, France
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90
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Tyc O, Zweers H, de Boer W, Garbeva P. Volatiles in Inter-Specific Bacterial Interactions. Front Microbiol 2015; 6:1412. [PMID: 26733959 PMCID: PMC4683202 DOI: 10.3389/fmicb.2015.01412] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/27/2015] [Indexed: 01/08/2023] Open
Abstract
The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures of well-described bacterial genera. In this study we aimed to understand how inter-specific bacterial interactions affect the composition, production and activity of volatiles. Four phylogenetically different bacterial species namely: Chryseobacterium, Dyella, Janthinobacterium, and Tsukamurella were selected. Earlier results had shown that pairwise combinations of these bacteria induced antimicrobial activity in agar media whereas this was not the case for monocultures. In the current study, we examined if these observations were also reflected by the production of antimicrobial volatiles. Thus, the identity and antimicrobial activity of volatiles produced by the bacteria were determined in monoculture as well in pairwise combinations. Antimicrobial activity of the volatiles was assessed against fungal, oomycetal, and bacterial model organisms. Our results revealed that inter-specific bacterial interactions affected volatiles blend composition. Fungi and oomycetes showed high sensitivity to bacterial volatiles whereas the effect of volatiles on bacteria varied between no effects, growth inhibition to growth promotion depending on the volatile blend composition. In total 35 volatile compounds were detected most of which were sulfur-containing compounds. Two commonly produced sulfur-containing volatile compounds (dimethyl disulfide and dimethyl trisulfide) were tested for their effect on three target bacteria. Here, we display the importance of inter-specific interactions on bacterial volatiles production and their antimicrobial activities.
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Affiliation(s)
- Olaf Tyc
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands; Department of Soil Quality, Wageningen University and Research CentreWageningen, Netherlands
| | - Hans Zweers
- Department of Microbial Ecology, Netherlands Institute of Ecology Wageningen, Netherlands
| | - Wietse de Boer
- Department of Microbial Ecology, Netherlands Institute of EcologyWageningen, Netherlands; Department of Soil Quality, Wageningen University and Research CentreWageningen, Netherlands
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology Wageningen, Netherlands
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91
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De Vrieze M, Pandey P, Bucheli TD, Varadarajan AR, Ahrens CH, Weisskopf L, Bailly A. Volatile Organic Compounds from Native Potato-associated Pseudomonas as Potential Anti-oomycete Agents. Front Microbiol 2015; 6:1295. [PMID: 26635763 PMCID: PMC4655239 DOI: 10.3389/fmicb.2015.01295] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 11/06/2015] [Indexed: 01/06/2023] Open
Abstract
The plant kingdom represents a prominent biodiversity island for microbes that associate with the below- or aboveground organs of vegetal species. Both the root and the leaf represent interfaces where dynamic biological interactions influence plant life. Beside well-studied communication strategies based on soluble compounds and protein effectors, bacteria were recently shown to interact both with host plants and other microbial species through the emissions of volatile organic compounds (VOCs). Focusing on the potato late blight-causing agent Phytophthora infestans, this work addresses the potential role of the bacterial volatilome in suppressing plant diseases. In a previous study, we isolated and identified a large collection of strains with anti-Phytophthora potential from both the phyllosphere and the rhizosphere of potato. Here we report the characterization and quantification of their emissions of biogenic volatiles, comparing 16 Pseudomonas strains differing in (i) origin of isolation (phyllosphere vs. rhizosphere), (ii) in vitro inhibition of P. infestans growth and sporulation behavior, and (iii) protective effects against late blight on potato leaf disks. We systematically tested the pharmacological inhibitory activity of core and strain-specific single compounds against P. infestans mycelial growth and sporangial behavior in order to identify key effective candidate molecules present in the complex natural VOCs blends. We envisage the plant bacterial microbiome as a reservoir for functional VOCs and establish the basis for finding the primary enzymatic toolset that enables the production of active components of the volatile bouquet in plant-associated bacteria. Comprehension of these functional interspecies interactions will open perspectives for the sustainable control of plant diseases in forthcoming agriculture.
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Affiliation(s)
- Mout De Vrieze
- Institute for Sustainability SciencesAgroscope, Zurich, Switzerland
- Institute for Plant Production SciencesAgroscope, Wädenswil, Switzerland
| | - Piyush Pandey
- Department of Microbiology, Assam UniversitySilchar, India
| | | | - Adithi R. Varadarajan
- Institute for Plant Production SciencesAgroscope, Wädenswil, Switzerland
- Swiss Institute of BioinformaticsWädenswil, Switzerland
| | - Christian H. Ahrens
- Institute for Plant Production SciencesAgroscope, Wädenswil, Switzerland
- Swiss Institute of BioinformaticsWädenswil, Switzerland
| | - Laure Weisskopf
- Institute for Sustainability SciencesAgroscope, Zurich, Switzerland
- Institute for Plant Production SciencesAgroscope, Wädenswil, Switzerland
- CHANGINS, Viticulture and Oenology, University of Applied Sciences and Arts Western SwitzerlandNyon, Switzerland
| | - Aurélien Bailly
- Institute for Sustainability SciencesAgroscope, Zurich, Switzerland
- Microbiology, Institute of Plant Biology, University of ZurichZurich, Switzerland
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92
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Schulz-Bohm K, Zweers H, de Boer W, Garbeva P. A fragrant neighborhood: volatile mediated bacterial interactions in soil. Front Microbiol 2015; 6:1212. [PMID: 26579111 PMCID: PMC4631045 DOI: 10.3389/fmicb.2015.01212] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 10/19/2015] [Indexed: 12/21/2022] Open
Abstract
There is increasing evidence that volatile organic compounds (VOCs) play essential roles in communication and competition between soil microorganisms. Here we assessed volatile-mediated interactions of a synthetic microbial community in a model system that mimics the natural conditions in the heterogeneous soil environment along the rhizosphere. Phylogenetic different soil bacterial isolates (Burkholderia sp., Dyella sp., Janthinobacterium sp., Pseudomonas sp., and Paenibacillus sp.) were inoculated as mixtures or monoculture in organic-poor, sandy soil containing artificial root exudates (ARE) and the volatile profile and growth were analyzed. Additionally, a two-compartment system was used to test if volatiles produced by inter-specific interactions in the rhizosphere can stimulate the activity of starving bacteria in the surrounding, nutrient-depleted soil. The obtained results revealed that both microbial interactions and shifts in microbial community composition had a strong effect on the volatile emission. Interestingly, the presence of a slow-growing, low abundant Paenibacillus strain significantly affected the volatile production by the other abundant members of the bacterial community as well as the growth of the interacting strains. Furthermore, volatiles released by mixtures of root-exudates consuming bacteria stimulated the activity and growth of starved bacteria. Besides growth stimulation, also an inhibition in growth was observed for starving bacteria exposed to microbial volatiles. The current work suggests that volatiles produced during microbial interactions in the rhizosphere have a significant long distance effect on microorganisms in the surrounding, nutrient-depleted soil.
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Affiliation(s)
- Kristin Schulz-Bohm
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW) Wageningen, Netherlands
| | - Hans Zweers
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW) Wageningen, Netherlands
| | - Wietse de Boer
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW) Wageningen, Netherlands ; Department of Soil Quality, Wageningen University Wageningen, Netherlands
| | - Paolina Garbeva
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW) Wageningen, Netherlands
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93
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Hol WHG, Garbeva P, Hordijk C, Hundscheid PJ, Gunnewiek PJAK, Van Agtmaal M, Kuramae EE, De Boer W. Non-random species loss in bacterial communities reduces antifungal volatile production. Ecology 2015; 96:2042-8. [PMID: 26405729 DOI: 10.1890/14-2359.1] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The contribution of low-abundance microbial species to soil ecosystems is easily overlooked because there is considerable overlap between metabolic abilities (functional redundancy) of dominant and subordinate microbial species. Here we studied how loss of less abundant soil bacteria affected the production of antifungal volatiles, an important factor in the natural control of soil-borne pathogenic fungi. We provide novel empirical evidence that the loss of soil bacterial species leads to a decline in the production of volatiles that suppress root pathogens. By using dilution-to-extinction for seven different soils we created bacterial communities with a decreasing number of species and grew them under carbon-limited conditions. Communities with high bacterial species richness produced volatiles that strongly reduced the hyphal growth of the pathogen Fusarium oxysporum. For most soil origins loss of bacterial species resulted in loss of antifungal volatile production. Analysis of the volatiles revealed that several known antifungal compounds were only produced in the more diverse bacterial communities. Our results suggest that less abundant bacterial species play an important role in antifungal volatile production by soil bacterial communities and, consequently, in the natural suppression of soil-borne pathogens.
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94
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van Agtmaal M, van Os GJ, Hol WHG, Hundscheid MPJ, Runia WT, Hordijk CA, de Boer W. Legacy effects of anaerobic soil disinfestation on soil bacterial community composition and production of pathogen-suppressing volatiles. Front Microbiol 2015. [PMID: 26217330 PMCID: PMC4498103 DOI: 10.3389/fmicb.2015.00701] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
There is increasing evidence that microbial volatiles (VOCs) play an important role in natural suppression of soil-borne diseases, but little is known on the factors that influence production of suppressing VOCs. In the current study we examined whether a stress-induced change in soil microbial community composition would affect the production by soils of VOCs suppressing the plant-pathogenic oomycete Pythium. Using pyrosequencing of 16S ribosomal gene fragments we compared the composition of bacterial communities in sandy soils that had been exposed to anaerobic disinfestation (AD), a treatment used to kill harmful soil organisms, with the composition in untreated soils. Three months after the AD treatment had been finished, there was still a clear legacy effect of the former anaerobic stress on bacterial community composition with a strong increase in relative abundance of the phylum Bacteroidetes and a significant decrease of the phyla Acidobacteria, Planctomycetes, Nitrospirae, Chloroflexi, and Chlorobi. This change in bacterial community composition coincided with loss of production of Pythium suppressing soil volatiles (VOCs) and of suppression of Pythium impacts on Hyacinth root development. One year later, the composition of the bacterial community in the AD soils was reflecting that of the untreated soils. In addition, both production of Pythium-suppressing VOCs and suppression of Pythium in Hyacinth bioassays had returned to the levels of the untreated soil. GC/MS analysis identified several VOCs, among which compounds known to be antifungal, that were produced in the untreated soils but not in the AD soils. These compounds were again produced 15 months after the AD treatment. Our data indicate that soils exposed to a drastic stress can temporarily lose pathogen suppressive characteristics and that both loss and return of these suppressive characteristics coincides with shifts in the soil bacterial community composition. Our data are supporting the suggested importance of microbial VOCs in the natural buffer of soils against diseases caused by soil-borne pathogens.
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Affiliation(s)
- Maaike van Agtmaal
- Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW Wageningen, Netherlands
| | - Gera J van Os
- Applied Plant Research, Flowerbulbs, Nursery Stock and Fruit, Wageningen University and Research Centre Lisse, Netherlands
| | - W H Gera Hol
- Department of Terrestrial Ecology, Netherlands Institute of Ecology, NIOO-KNAW Wageningen, Netherlands
| | - Maria P J Hundscheid
- Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW Wageningen, Netherlands
| | - Willemien T Runia
- Applied Plant Research, Subdivision Arable Farming, Multifunctional Agriculture and Field Production of Vegetables, Wageningen University and Research Centre Lelystad, Netherlands
| | - Cornelis A Hordijk
- Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW Wageningen, Netherlands
| | - Wietse de Boer
- Department of Microbial Ecology, Netherlands Institute of Ecology, NIOO-KNAW Wageningen, Netherlands ; Department of Soil Quality, Wageningen University and Research Centre Wageningen, Netherlands
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95
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Volatile affairs in microbial interactions. ISME JOURNAL 2015; 9:2329-35. [PMID: 26023873 DOI: 10.1038/ismej.2015.42] [Citation(s) in RCA: 241] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 02/15/2015] [Accepted: 02/23/2015] [Indexed: 12/31/2022]
Abstract
Microorganisms are important factors in shaping our environment. One key characteristic that has been neglected for a long time is the ability of microorganisms to release chemically diverse volatile compounds. At present, it is clear that the blend of volatiles released by microorganisms can be very complex and often includes many unknown compounds for which the chemical structures remain to be elucidated. The biggest challenge now is to unravel the biological and ecological functions of these microbial volatiles. There is increasing evidence that microbial volatiles can act as infochemicals in interactions among microbes and between microbes and their eukaryotic hosts. Here, we review and discuss recent advances in understanding the natural roles of volatiles in microbe-microbe interactions. Specific emphasis will be given to the antimicrobial activities of microbial volatiles and their effects on bacterial quorum sensing, motility, gene expression and antibiotic resistance.
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96
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Cernava T, Aschenbrenner IA, Grube M, Liebminger S, Berg G. A novel assay for the detection of bioactive volatiles evaluated by screening of lichen-associated bacteria. Front Microbiol 2015; 6:398. [PMID: 25983730 PMCID: PMC4416446 DOI: 10.3389/fmicb.2015.00398] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 04/17/2015] [Indexed: 11/16/2022] Open
Abstract
Volatile organic compounds (VOCs) produced by microorganisms are known both for their effect on pathogens and their role as mediators in various interactions and communications. Previous studies have demonstrated the importance of VOCs for ecosystem functioning as well as their biotechnological potential, but screening for bioactive volatiles remained difficult. We have developed an efficient testing assay that is based on two multi-well plates, separated by a sealing silicone membrane, two tightening clamps, and variable growth media, or indicators. The experiment design as presented here is a novel and robust technique to identify positive as well as negative VOC effects on the growth of a target organism and to test for specific substances e.g., hydrogen cyanide which can be detected with a suitable indicator. While the first pre-screening assay is primarily based on indicator color change and visible growth diameter reduction, we also introduce an advanced and quantitatively precise experiment design. This adaptation involves qPCR-based quantification of viable target cells after concluding the treatment with VOCs. Therefore, we chose preselected active isolates and compared the partial 16S rRNA gene copy number of headspace-exposed E. coli with non-treated controls. Separately obtained headspace SPME and GC/MS-based profiles of selected bacterial isolates revealed the presence of specific and unique signatures which suggests divergent modes of action. The assay was evaluated by screening 100 isolates of lung lichen-associated bacteria. Approximately one quarter of the isolates showed VOC-based antibacterial and/or antifungal activity; mainly Pseudomonas and Stenotrophomonas species were identified as producers of bioactive volatiles.
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Affiliation(s)
- Tomislav Cernava
- Institute of Environmental Biotechnology, Graz University of Technology Graz, Austria
| | - Ines A Aschenbrenner
- Institute of Environmental Biotechnology, Graz University of Technology Graz, Austria ; Institute of Plant Sciences, University of Graz Graz, Austria
| | - Martin Grube
- Institute of Plant Sciences, University of Graz Graz, Austria
| | | | - Gabriele Berg
- Institute of Environmental Biotechnology, Graz University of Technology Graz, Austria
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97
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Kanchiswamy CN, Malnoy M, Maffei ME. Chemical diversity of microbial volatiles and their potential for plant growth and productivity. FRONTIERS IN PLANT SCIENCE 2015; 6:151. [PMID: 25821453 PMCID: PMC4358370 DOI: 10.3389/fpls.2015.00151] [Citation(s) in RCA: 213] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 02/24/2015] [Indexed: 05/02/2023]
Abstract
Microbial volatile organic compounds (MVOCs) are produced by a wide array of microorganisms ranging from bacteria to fungi. A growing body of evidence indicates that MVOCs are ecofriendly and can be exploited as a cost-effective sustainable strategy for use in agricultural practice as agents that enhance plant growth, productivity, and disease resistance. As naturally occurring chemicals, MVOCs have potential as possible alternatives to harmful pesticides, fungicides, and bactericides as well as genetic modification. Recent studies performed under open field conditions demonstrate that efficiently adopting MVOCs may contribute to sustainable crop protection and production. We review here the chemical diversity of MVOCs by describing microbial-plants and microbial-microbial interactions. Furthermore, we discuss MVOCs role in inducing phenotypic plant responses and their potential physiological effects on crops. Finally, we analyze potential and actual limitations for MVOC use and deployment in field conditions as a sustainable strategy for improving productivity and reducing pesticide use.
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Affiliation(s)
- Chidananda Nagamangala Kanchiswamy
- Research and Innovation Center, Biology and Genomic of Fruit Plants, Fondazione Edmund MachTrento, Italy,
- *Correspondence: Chidananda Nagamangala Kanchiswamy, Research and Innovation Center, Biology and Genomic of Fruit Plants, Fondazione Edmund Mach, Via E.Mach 1, San Michele all'Adige, Trento, Italy
| | - Mickael Malnoy
- Research and Innovation Center, Biology and Genomic of Fruit Plants, Fondazione Edmund MachTrento, Italy,
| | - Massimo E. Maffei
- Plant Physiology Unit, Department of Life Sciences and Systems Biology, University of TurinTurin, Italy
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98
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Liu XM, Zhang H. The effects of bacterial volatile emissions on plant abiotic stress tolerance. FRONTIERS IN PLANT SCIENCE 2015; 6:774. [PMID: 26442083 PMCID: PMC4585079 DOI: 10.3389/fpls.2015.00774] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/10/2015] [Indexed: 05/18/2023]
Abstract
Plant growth-promoting rhizobacteria (PGPR) are beneficial plant symbionts that have been successfully used in agriculture to increase seedling emergence, plant weight, crop yield, and disease resistance. Some PGPR strains release volatile organic compounds (VOCs) that can directly and/or indirectly mediate increases in plant biomass, disease resistance, and abiotic stress tolerance. This mini-review focuses on the enhancement of plant abiotic stress tolerance by bacterial VOCs. The review considers how PGPR VOCs induce tolerance to salinity and drought stress and also how they improve sulfur and iron nutrition in plants. The potential complexities in evaluating the effects of PGPR VOCs are also discussed.
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Affiliation(s)
| | - Huiming Zhang
- *Correspondence: Huiming Zhang, Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 3888 Chenhua Road, Shanghai 201602, China,
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99
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Comolli LR. Intra- and inter-species interactions in microbial communities. Front Microbiol 2014; 5:629. [PMID: 25505455 PMCID: PMC4241841 DOI: 10.3389/fmicb.2014.00629] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 11/03/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Luis R Comolli
- Beamline 4.2.2, Advanced Light Source, ALS-Molecular Biology Consortium Berkeley, CA, USA
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