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Kuhn T, Mamin M, Bindschedler S, Bshary R, Estoppey A, Gonzalez D, Palmieri F, Junier P, Richter XYL. Spatial scales of competition and a growth-motility trade-off interact to determine bacterial coexistence. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211592. [PMID: 36483758 PMCID: PMC9727664 DOI: 10.1098/rsos.211592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/18/2022] [Indexed: 06/17/2023]
Abstract
The coexistence of competing species is a long-lasting puzzle in evolutionary ecology research. Despite abundant experimental evidence showing that the opportunity for coexistence decreases as niche overlap increases between species, bacterial species and strains competing for the same resources are commonly found across diverse spatially heterogeneous habitats. We thus hypothesized that the spatial scale of competition may play a key role in determining bacterial coexistence, and interact with other mechanisms that promote coexistence, including a growth-motility trade-off. To test this hypothesis, we let two Pseudomonas putida strains compete at local and regional scales by inoculating them either in a mixed droplet or in separate droplets in the same Petri dish, respectively. We also created conditions that allow the bacterial strains to disperse across abiotic or fungal hyphae networks. We found that competition at the local scale led to competitive exclusion while regional competition promoted coexistence. When competing in the presence of dispersal networks, the growth-motility trade-off promoted coexistence only when the strains were inoculated in separate droplets. Our results provide a mechanism by which existing laboratory data suggesting competitive exclusion at a local scale is reconciled with the widespread coexistence of competing bacterial strains in complex natural environments with dispersal.
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Affiliation(s)
- Thierry Kuhn
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
- Laboratory of Eco-Ethology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Marine Mamin
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Saskia Bindschedler
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Redouan Bshary
- Laboratory of Eco-Ethology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Aislinn Estoppey
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Diego Gonzalez
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Fabio Palmieri
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Pilar Junier
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Xiang-Yi Li Richter
- Laboratory of Microbiology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
- Laboratory of Eco-Ethology, Institute of Biology, University of Neuchâtel, Rue Émile-Argand 11, CH-2000 Neuchâtel, Switzerland
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Sun Y, Su J, Ali A, Zhang S, Zheng Z, Min Y. Effect of fungal pellets on denitrifying bacteria at low carbon to nitrogen ratio: Nitrate removal, extracellular polymeric substances, and potential functions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 847:157591. [PMID: 35901879 DOI: 10.1016/j.scitotenv.2022.157591] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/19/2022] [Accepted: 07/19/2022] [Indexed: 06/15/2023]
Abstract
This research aims to elucidate the effect of fungal pellets (FP) on denitrifying bacteria regarding nitrate (NO3--N) removal, extracellular polymeric substances (EPS), and potential functions at a low carbon to nitrogen (C/N) ratio. A symbiotic system of FP and denitrifying bacteria GF2 was established. The symbiotic system showed 100% NO3--N removal efficiency (4.07 mg L-1 h-1) at 6 h and enhanced electron transfer capability at C/N = 1.5. The interactions between FP and denitrifying bacteria promoted the production of polysaccharides (PS) in EPS. Both the increased PS and the PS provided by FP as well as protein and humic acid-like substances in EPS could be consumed by denitrifying bacteria. FP acted as a protector and provided habitat and nutrients for denitrifying bacteria as well as improved the ability of carbohydrate metabolism, amino metabolism, and nitrogen metabolism of denitrifying bacteria. This study provides a new perspective on the relationship between FP and denitrifying bacteria.
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Affiliation(s)
- Yi Sun
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Junfeng Su
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Amjad Ali
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Shuai Zhang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Zhijie Zheng
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Yitian Min
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
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3
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Li W, Li WB, Xing LJ, Guo SX. Effect of arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) on microorganism of phenanthrene and pyrene contaminated soils. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2022; 25:240-251. [PMID: 35549569 DOI: 10.1080/15226514.2022.2071832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A pot experiment was performed to investigate the effect of phytoremediation (CK, using tall fescue), fungi remediation (GV, using Glomus versiforme), bacterial remediation (PS, using Pseudomonas fluorescens Ps2-6), and microbial-phytoremediation (GVPS, using three species) on removing polycyclic aromatic hydrocarbons (PAHs) and the microbial diversity in soils. Inoculation with G. versiforme and P. fluorescens could increase the biomass of tall fescue and the accumulation of phenanthrene (PHE) and pyrene (PYR) in plants. Among them, the highest PHE and PYR removal efficiencies and highest biomass of tall fescue were observed in the GVPS treatment and the microbial diversity in contaminated soil was changed, the result revealed that Proteobacteria and Ascomycota were the dominant bacterial phylum and fungal phylum in all treatments, while more Proteobacteria were detected in GVPS treatment. At the genus level, the abundance of Sphingomonas (3.17%), Pseudomonas (2.05%), and Fusarium (8.65%) treated with GVPS increased compared with other treatments. These pieces of evidence contribute to a better understanding of the mechanisms involved in the combined microbial-phytoremediation strategies for PAHs-contaminated soils, especially the effects of microbial-phytoremediation on rhizosphere microbial diversity.
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Affiliation(s)
- Wei Li
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, China
| | - Wen-Bin Li
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, China
| | - Li-Jun Xing
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, China
| | - Shao-Xia Guo
- College of Landscape Architecture and Forestry, Qingdao Agricultural University, Qingdao, China
- Institute of Mycorrhizal Biotechnology, Qingdao Agricultural University, Qingdao, China
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Narain-Ford DM, Bartholomeus RP, Dekker SC, van Wezel AP. Natural Purification Through Soils: Risks and Opportunities of Sewage Effluent Reuse in Sub-surface Irrigation. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2020; 250:85-117. [PMID: 32939618 DOI: 10.1007/398_2020_49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- Dominique M Narain-Ford
- Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, The Netherlands.
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands.
- KWR Water Research Institute, Nieuwegein, The Netherlands.
| | - Ruud P Bartholomeus
- KWR Water Research Institute, Nieuwegein, The Netherlands
- Soil Physics and Land Management, Wageningen University & Research, Wageningen, The Netherlands
| | - Stefan C Dekker
- Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, The Netherlands
- Department of Science, Faculty of Management, Science and Technology, Open University, Heerlen, The Netherlands
| | - Annemarie P van Wezel
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
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Li J, Luo C, Zhang G, Zhang D. Coupling magnetic-nanoparticle mediated isolation (MMI) and stable isotope probing (SIP) for identifying and isolating the active microbes involved in phenanthrene degradation in wastewater with higher resolution and accuracy. WATER RESEARCH 2018; 144:226-234. [PMID: 30032019 DOI: 10.1016/j.watres.2018.07.036] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 07/05/2018] [Accepted: 07/14/2018] [Indexed: 06/08/2023]
Abstract
Stable isotope probing (SIP) is a cultivation-independent approach identifying the functional microbes in their natural habitats, possibly linking their identities to functions. DNA-SIP is well-established but suffers from the shift of 12C-DNA into the heavy DNA (13C-DNA) fraction, which significantly reduces the resolution and accuracy. In this study, we coupled magnetic-nanoparticle mediated isolation (MMI) and DNA-SIP, namely MMI-SIP, to identify the active microbes involved in phenanthrene degradation from PAH-contaminated wastewater. Microbes affiliated to Pseudomonas and Sphingobium were responsible for in situ phenanthrene metabolism from the SIP results, and Pigmentiphaga was only unraveled for phenanthrene degradation in the MMI and MMI-SIP microcosms. MMI-SIP also significantly increased the enrichment of the above microbes and genes encoding the alpha subunit of the PAH-ring hydroxylating dioxygenase (PAH-RHDα) in the heavy DNA fractions. Our findings suggest that MMI-SIP is a powerful tool, with higher resolution and accuracy, to distinguish the active microbes involved in phenanthrene metabolism in the wastewater, provide a more precise map of functional microbial communities, and offer suggestions for effective management for wastewater treatment plants.
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Affiliation(s)
- Jibing Li
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Chunling Luo
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China.
| | - Gan Zhang
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China
| | - Dayi Zhang
- School of Environment, Tsinghua University, Beijing, 100084, China.
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6
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Worrich A, Wick LY, Banitz T. Ecology of Contaminant Biotransformation in the Mycosphere: Role of Transport Processes. ADVANCES IN APPLIED MICROBIOLOGY 2018; 104:93-133. [PMID: 30143253 DOI: 10.1016/bs.aambs.2018.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fungi and bacteria often share common microhabitats. Their co-occurrence and coevolution give rise to manifold ecological interactions in the mycosphere, here defined as the microhabitats surrounding and affected by hyphae and mycelia. The extensive structure of mycelia provides ideal "logistic networks" for transport of bacteria and matter in structurally and chemically heterogeneous soil ecosystems. We describe the characteristics of the mycosphere as a unique and highly dynamic bacterial habitat and a hot spot for contaminant biotransformation. In particular, we emphasize the role of the mycosphere for (i) bacterial dispersal and colonization of subsurface interfaces and new habitats, (ii) matter transport processes and contaminant bioaccessibility, and (iii) the functional stability of microbial ecosystems when exposed to environmental fluctuations such as stress or disturbances. Adopting concepts from ecological theory, the chapter disentangles bacterial-fungal impacts on contaminant biotransformation in a systemic approach that interlinks empirical data from microbial ecosystems with simulation data from computational models. This approach provides generic information on key factors, processes, and ecological principles that drive microbial contaminant biotransformation in soil. We highlight that the transport processes create favorable habitat conditions for efficient bacterial contaminant degradation in the mycosphere. In-depth observation, understanding, and prediction of the role of mycosphere transport processes will support the use of bacterial-fungal interactions in nature-based solutions for contaminant biotransformation in natural and man-made ecosystems, respectively.
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Affiliation(s)
- Anja Worrich
- Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Lukas Y Wick
- Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany.
| | - Thomas Banitz
- Department of Ecological Modelling, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
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König S, Worrich A, Banitz T, Harms H, Kästner M, Miltner A, Wick LY, Frank K, Thullner M, Centler F. Functional Resistance to Recurrent Spatially Heterogeneous Disturbances Is Facilitated by Increased Activity of Surviving Bacteria in a Virtual Ecosystem. Front Microbiol 2018; 9:734. [PMID: 29696013 PMCID: PMC5904252 DOI: 10.3389/fmicb.2018.00734] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 03/28/2018] [Indexed: 11/13/2022] Open
Abstract
Bacterial degradation of organic compounds is an important ecosystem function with relevance to, e.g., the cycling of elements or the degradation of organic contaminants. It remains an open question, however, to which extent ecosystems are able to maintain such biodegradation function under recurrent disturbances (functional resistance) and how this is related to the bacterial biomass abundance. In this paper, we use a numerical simulation approach to systematically analyze the dynamic response of a microbial population to recurrent disturbances of different spatial distribution. The spatially explicit model considers microbial degradation, growth, dispersal, and spatial networks that facilitate bacterial dispersal mimicking effects of mycelial networks in nature. We find: (i) There is a certain capacity for high resistance of biodegradation performance to recurrent disturbances. (ii) If this resistance capacity is exceeded, spatial zones of different biodegradation performance develop, ranging from no or reduced to even increased performance. (iii) Bacterial biomass and biodegradation dynamics respond inversely to the spatial fragmentation of disturbances: overall biodegradation performance improves with increasing fragmentation, but bacterial biomass declines. (iv) Bacterial dispersal networks can enhance functional resistance against recurrent disturbances, mainly by reactivating zones in the core of disturbed areas, even though this leads to an overall reduction of bacterial biomass.
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Affiliation(s)
- Sara König
- Department of Ecological Modelling, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
- Department of Environmental Microbiology, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
- Institute of Environmental Systems Research, University of Osnabrück, Osnabrück, Germany
| | - Anja Worrich
- Department of Environmental Microbiology, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
- Department of Environmental Biotechnology, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Thomas Banitz
- Department of Ecological Modelling, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Hauke Harms
- Department of Environmental Microbiology, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Matthias Kästner
- Department of Environmental Biotechnology, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Anja Miltner
- Department of Environmental Biotechnology, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Lukas Y. Wick
- Department of Environmental Microbiology, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Karin Frank
- Department of Ecological Modelling, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
- Institute of Environmental Systems Research, University of Osnabrück, Osnabrück, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Martin Thullner
- Department of Environmental Microbiology, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Florian Centler
- Department of Environmental Microbiology, The UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany
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Ren X, Zeng G, Tang L, Wang J, Wan J, Liu Y, Yu J, Yi H, Ye S, Deng R. Sorption, transport and biodegradation - An insight into bioavailability of persistent organic pollutants in soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 610-611:1154-1163. [PMID: 28847136 DOI: 10.1016/j.scitotenv.2017.08.089] [Citation(s) in RCA: 280] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 08/09/2017] [Accepted: 08/09/2017] [Indexed: 05/13/2023]
Abstract
Contamination of soils with persistent organic pollutants (POPs), such as organochlorine pesticide, polybrominated diphenyl ethers, halohydrocarbon, polycyclic aromatic hydrocarbons (PAHs) is of increasing concern. Microbial degradation is potential mechanism for the removal of POPs, but it is often restricted by low bioavailability of POPs. Thus, it is important to enhance bioavailability of POPs in soil bioremediation. A series of reviews on bioavailability of POPs has been published in the past few years. However, bioavailability of POPs in relation to soil organic matter, minerals and soil microbes has been little studied. To fully understand POPs bioavailability in soil, research on interactions of POPs with soil components and microbial responses in bioavailability limitation conditions are needed. This review focuses on bioavailability mechanisms of POPs in terms of sorption, transport and microbial adaptation, which is particularly novel. In consideration of the significance of bioavailability, further studies should investigate the influence of various bioremediation strategies on POPs bioavailability.
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Affiliation(s)
- Xiaoya Ren
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Guangming Zeng
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
| | - Lin Tang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Jingjing Wang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Jia Wan
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Yani Liu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Jiangfang Yu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Huan Yi
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Shujing Ye
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Rui Deng
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
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Otto S, Harms H, Wick LY. Effects of predation and dispersal on bacterial abundance and contaminant biodegradation. FEMS Microbiol Ecol 2016; 93:fiw241. [DOI: 10.1093/femsec/fiw241] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 12/01/2016] [Indexed: 11/12/2022] Open
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10
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Catch me if you can: dispersal and foraging of Bdellovibrio bacteriovorus 109J along mycelia. ISME JOURNAL 2016; 11:386-393. [PMID: 27824344 DOI: 10.1038/ismej.2016.135] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/17/2016] [Accepted: 08/29/2016] [Indexed: 11/08/2022]
Abstract
To cope with heterogeneous environments and resource distributions, filamentous fungi have evolved a spatially extensive growth enabling their hyphae to penetrate air-water interfaces and pass through air-filled pores. Such mycelia are also known to act as dispersal networks for the mobilisation of bacteria ('fungal highways') and connection of microbial microhabitats. Hitherto, however, nothing is known about the effect of mycelia-based dispersal on interactions between bacterial predators and their prey and concomitant effects on biomass formation. We here hypothesise that mycelia enable the contact between predators and their prey and shape a prey's population. We investigated the impact of predation by Bdellovibrio bacteriovorus 109J on the growth of its potential prey Pseudomonas fluorescens LP6a in the presence of mycelia. Our data give evidence that hyphae increase the accessibility of the prey to B. bacteriovorus 109J and, hence, allow for efficient foraging and shaping of prey populations not seen in the absence of mycelia. To test our hypothesis tailored microbial landscapes were used for better reduction of emerging properties in complex systems. Our data suggest that mycelia have substantial influence on prey-predator relationship and hereby may promote the structure of prey and predator populations and, hence, may be a determinant for biomass formation in heterogeneous environments.
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Berthold T, Centler F, Hübschmann T, Remer R, Thullner M, Harms H, Wick LY. Mycelia as a focal point for horizontal gene transfer among soil bacteria. Sci Rep 2016; 6:36390. [PMID: 27811990 PMCID: PMC5095653 DOI: 10.1038/srep36390] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 10/12/2016] [Indexed: 11/09/2022] Open
Abstract
Horizontal gene transfer (HGT) is a main mechanism of bacterial evolution endowing bacteria with new genetic traits. The transfer of mobile genetic elements such as plasmids (conjugation) requires the close proximity of cells. HGT between genetically distinct bacteria largely depends on cell movement in water films, which are typically discontinuous in natural systems like soil. Using laboratory microcosms, a bacterial reporter system and flow cytometry, we here investigated if and to which degree mycelial networks facilitate contact of and HGT between spatially separated bacteria. Our study shows that the network structures of mycelia promote bacterial HGT by providing continuous liquid films in which bacterial migration and contacts are favoured. This finding was confirmed by individual-based simulations, revealing that the tendency of migrating bacteria to concentrate in the liquid film around hyphae is a key factor for improved HGT along mycelial networks. Given their ubiquity, we propose that hyphae can act as focal point for HGT and genetic adaptation in soil.
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Affiliation(s)
- Tom Berthold
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany
| | - Florian Centler
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany
| | - Thomas Hübschmann
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany
| | - Rita Remer
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany
| | - Martin Thullner
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany
| | - Hauke Harms
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5E, 04103 Leipzig, Germany
| | - Lukas Y. Wick
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstraße 15, 04318, Leipzig, Germany
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