1
|
David GM, Pimentel IM, Rehsen PM, Vermiert AM, Leese F, Gessner MO. Multiple stressors affecting microbial decomposer and litter decomposition in restored urban streams: Assessing effects of salinization, increased temperature, and reduced flow velocity in a field mesocosm experiment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 943:173669. [PMID: 38839005 DOI: 10.1016/j.scitotenv.2024.173669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 05/12/2024] [Accepted: 05/29/2024] [Indexed: 06/07/2024]
Abstract
A multitude of anthropogenic stressors impact biological communities and ecosystem processes in urban streams. Prominent among them are salinization, increased temperature, and altered flow regimes, all of which can affect microbial decomposer communities and litter decomposition, a fundamental ecosystem process in streams. Impairments caused by these stressors individually or in combination and recovery of communities and ecosystem processes after release from these stressors are not well understood. To improve our understanding of multiple stressors impacts we performed an outdoor stream mesocosm experiment with 64 experimental units to assess the response of microbial litter decomposers and decomposition. The three stressors we applied in a full-factorial design were increased salinity (NaCl addition, 0.53 mS cm-1 above ambient), elevated temperature (3.5 °C above ambient), and reduced flow velocity (3.5 vs 14.2 cm s-1). After two weeks of stressor exposure (first sampling) and two subsequent weeks of recovery (second sampling), we determined leaf-associated microbial respiration, fungal biomass, and the sporulation activity and community composition of aquatic hyphomycetes in addition to decomposition rates of black alder (Alnus glutinosa) leaves confined in fine-mesh litter bags. Microbial colonization of the litter was accompanied by significant mass loss in all mesocosms. However, there was little indication that mass loss, microbial respiration, fungal biomass, sporulation rate or community composition of aquatic hyphomycetes was strongly affected by either single stressors or their interactions. Two exceptions were temperature effects on sporulation and decomposition rate. Similarly, no notable differences among mesocosms were observed after the recovery phase. These results suggest that microbial decomposers and leaf litter decomposition are either barely impaired by exposure to the tested stressors at the levels applied in our experiment, or that communities in restored urban streams are well adapted to cope with these stressor levels.
Collapse
Affiliation(s)
- Gwendoline M David
- Department of Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Stechlin, Germany.
| | - Iris Madge Pimentel
- Aquatic Ecosystem Research, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
| | - Philipp M Rehsen
- Aquatic Ecosystem Research, Faculty of Biology, University of Duisburg-Essen, Essen, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | - Anna-Maria Vermiert
- Department of Animal Ecology, Evolution and Biodiversity, Ruhr University Bochum, Bochum, Germany
| | - Florian Leese
- Aquatic Ecosystem Research, Faculty of Biology, University of Duisburg-Essen, Essen, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | - Mark O Gessner
- Department of Plankton and Microbial Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Stechlin, Germany; Department of Ecology, Berlin Institute of Technology (TU Berlin), Berlin, Germany
| |
Collapse
|
2
|
Graça D, Arias-Real R, Fernandes I, Cássio F, Pascoal C. Fungal identity mediates the impacts of multiple stressors on freshwater ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 937:173466. [PMID: 38788941 DOI: 10.1016/j.scitotenv.2024.173466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 05/16/2024] [Accepted: 05/21/2024] [Indexed: 05/26/2024]
Abstract
Predicting how multiple anthropogenic stressors affect natural ecosystems is a major challenge in ecology. Freshwater ecosystems are threatened worldwide by multiple co-occurring stressors, which can affect aquatic biodiversity, ecosystem functioning and human wellbeing. In stream ecosystems, aquatic fungi play a crucial role in global biogeochemical cycles and food web dynamics, therefore, assessing the functional consequences of fungal biodiversity loss under multiple stressors is crucial. Here, a microcosm approach was used to investigate the effects of multiple stressors (increased temperature and nutrients, drying, and biodiversity loss) on three ecosystem processes: organic matter decomposition, fungal reproduction, and fungal biomass accrual. Net effects of stressors were antagonistic for organic matter decomposition, but additive for fungal reproduction and biomass accrual. Net effects of biodiversity were mainly positive for all processes, even under stress, demonstrating that diversity assures the maintenance of ecosystem processes. Fungal species displayed distinct contributions to each ecosystem process. Furthermore, species with negligible contributions under control conditions changed their role under stress, either enhancing or impairing the communities' performance, emphasizing the importance of fungal species identity. Our study highlights that distinct fungal species have different sensitivities to environmental variability and have different influence on the overall performance of the community. Therefore, preserving high fungal diversity is crucial to maintain fungal species with key ecosystem functions within aquatic communities in face of environmental change.
Collapse
Affiliation(s)
- Diana Graça
- CBMA, Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; IB-S, Institute of Science and Innovation for Bio-Sustainability, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
| | - Rebeca Arias-Real
- CBMA, Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; IB-S, Institute of Science and Innovation for Bio-Sustainability, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028 Barcelona, Spain.
| | - Isabel Fernandes
- CBMA, Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; IB-S, Institute of Science and Innovation for Bio-Sustainability, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
| | - Fernanda Cássio
- CBMA, Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; IB-S, Institute of Science and Innovation for Bio-Sustainability, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
| | - Cláudia Pascoal
- CBMA, Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; IB-S, Institute of Science and Innovation for Bio-Sustainability, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
| |
Collapse
|
3
|
Granados V, Arias-Real R, Gutiérrez-Cánovas C, Obrador B, Butturini A. Multiple drying aspects shape dissolved organic matter composition in intermittent streams. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 852:158376. [PMID: 36049684 DOI: 10.1016/j.scitotenv.2022.158376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 08/24/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
Water availability is a fundamental driver of biogeochemical processing in highly dynamic ecosystems such as intermittent rivers and ephemeral streams (IRES), which are recognized as the most common fluvial ecosystem globally. Because of their global extent, IRES have a remarkable contribution to organic matter processing, which is expected to intensify as climate change and water extraction expand IRES extension. Nevertheless, the effect of the complexity of the drying process on river biogeochemistry remains unclear. This study investigated how drying aspects affect the dissolved organic carbon (DOC) concentration and composition in 35 streams along a wide flow-intermittence gradient in the NE Iberian Peninsula. To do that, four drying aspects: annual drying duration, annual frequency, duration of the last drying event, and time since the last drying event were characterized. Results showed that DOC concentration and the contribution of humic-like compounds were positively associated with intensifying drying conditions. In addition, protein-like compounds decreased over the drying gradient. More specifically, changes in DOC concentration were driven mainly by annual drying duration, whereas annual drying frequency and the duration of the last drying event jointly explained dissolved organic matter composition. These results suggest that the quantity and composition of dissolved organic matter in streams respond differently to the temporal aspects of the drying process. Our study can help to better anticipate changes in organic matter in the context of climate change.
Collapse
Affiliation(s)
- Verónica Granados
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Rebeca Arias-Real
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, Barcelona, Spain; Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal; Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal.
| | - Cayetano Gutiérrez-Cánovas
- Biological Invasions Group, Department of Integrative Ecology, Doñana Biological Station (EBD-CSIC), Av. Américo Vespucio, 26, Isla de la Cartuja, 41092 Seville, Spain
| | - Biel Obrador
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Andrea Butturini
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, Barcelona, Spain
| |
Collapse
|
4
|
Hayer M, Wymore AS, Hungate BA, Schwartz E, Koch BJ, Marks JC. Microbes on decomposing litter in streams: entering on the leaf or colonizing in the water? THE ISME JOURNAL 2022; 16:717-725. [PMID: 34580429 PMCID: PMC8857200 DOI: 10.1038/s41396-021-01114-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 08/29/2021] [Accepted: 09/09/2021] [Indexed: 01/04/2023]
Abstract
When leaves fall in rivers, microbial decomposition commences within hours. Microbial assemblages comprising hundreds of species of fungi and bacteria can vary with stream conditions, leaf litter species, and decomposition stage. In terrestrial ecosystems, fungi and bacteria that enter soils with dead leaves often play prominent roles in decomposition, but their role in aquatic decomposition is less known. Here, we test whether fungi and bacteria that enter streams on senesced leaves are growing during decomposition and compare their abundances and growth to bacteria and fungi that colonize leaves in the water. We employ quantitative stable isotope probing to identify growing microbes across four leaf litter species and two decomposition times. We find that most of the growing fungal species on decomposing leaves enter the water with the leaf, whereas most growing bacteria colonize from the water column. Results indicate that the majority of bacteria found on litter are growing, whereas the majority of fungi are dormant. Both bacterial and fungal assemblages differed with leaf type on the dried leaves and throughout decomposition. This research demonstrates the importance of fungal species that enter with the leaf on aquatic decomposition and the prominence of bacteria that colonize decomposing leaves in the water.
Collapse
Affiliation(s)
- Michaela Hayer
- Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA.
| | - Adam S. Wymore
- grid.167436.10000 0001 2192 7145Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH 03824 USA
| | - Bruce A. Hungate
- grid.261120.60000 0004 1936 8040Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011 USA
| | - Egbert Schwartz
- grid.261120.60000 0004 1936 8040Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011 USA
| | - Benjamin J. Koch
- grid.261120.60000 0004 1936 8040Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011 USA
| | - Jane C. Marks
- grid.261120.60000 0004 1936 8040Center for Ecosystem Science and Society, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011 USA
| |
Collapse
|
5
|
Carl S, Mohr S, Sahm R, Baschien C. Laboratory conditions can change the complexity and composition of the natural aquatic mycobiome on Alnus glutinosa leaf litter. FUNGAL ECOL 2022. [DOI: 10.1016/j.funeco.2022.101142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
6
|
Bashir I, War AF, Rafiq I, Reshi ZA, Rashid I, Shouche YS. Phyllosphere microbiome: Diversity and functions. Microbiol Res 2021; 254:126888. [PMID: 34700185 DOI: 10.1016/j.micres.2021.126888] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/15/2021] [Accepted: 09/30/2021] [Indexed: 12/28/2022]
Abstract
Phyllosphere or aerial surface of plants represents the globally largest and peculiar microbial habitat that inhabits diverse and rich communities of bacteria, fungi, viruses, cyanobacteria, actinobacteria, nematodes, and protozoans. These hyperdiverse microbial communities are related to the host's specific functional traits and influence the host's physiology and the ecosystem's functioning. In the last few years, significant advances have been made in unravelling several aspects of phyllosphere microbiology, including diversity and microbial community composition, dynamics, and functional interactions. This review highlights the current knowledge about the assembly, structure, and composition of phyllosphere microbial communities across spatio-temporal scales, besides functional significance of different microbial communities to the plant host and the surrounding environment. The knowledge will help develop strategies for modelling and manipulating these highly beneficial microbial consortia for furthering scientific inquiry into their interactions with the host plants and also for their useful and economic utilization.
Collapse
Affiliation(s)
- Iqra Bashir
- Department of Botany, University of Kashmir, Srinagar, 190006, Jammu and Kashmir, India.
| | - Aadil Farooq War
- Department of Botany, University of Kashmir, Srinagar, 190006, Jammu and Kashmir, India
| | - Iflah Rafiq
- Department of Botany, University of Kashmir, Srinagar, 190006, Jammu and Kashmir, India
| | - Zafar A Reshi
- Department of Botany, University of Kashmir, Srinagar, 190006, Jammu and Kashmir, India
| | - Irfan Rashid
- Department of Botany, University of Kashmir, Srinagar, 190006, Jammu and Kashmir, India
| | | |
Collapse
|
7
|
Baudy P, Zubrod JP, Konschak M, Röder N, Nguyen TH, Schreiner VC, Baschien C, Schulz R, Bundschuh M. Environmentally relevant fungicide levels modify fungal community composition and interactions but not functioning. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 285:117234. [PMID: 33962304 DOI: 10.1016/j.envpol.2021.117234] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 04/16/2021] [Accepted: 04/21/2021] [Indexed: 05/25/2023]
Abstract
Aquatic hyphomycetes (AHs), a group of saprotrophic fungi adapted to submerged leaf litter, play key functional roles in stream ecosystems as decomposers and food source for higher trophic levels. Fungicides, controlling fungal pathogens, target evolutionary conserved molecular processes in fungi and contaminate streams via their use in agricultural and urban landscapes. Thus fungicides pose a risk to AHs and the functions they provide. To investigate the impacts of fungicide exposure on the composition and functioning of AH communities, we exposed four AH species in monocultures and mixed cultures to increasing fungicide concentrations (0, 5, 50, 500, and 2500 μg/L). We assessed the biomass of each species via quantitative real-time PCR. Moreover, leaf decomposition was investigated. In monocultures, none of the species was affected at environmentally relevant fungicide levels (5 and 50 μg/L). The two most tolerant species were able to colonize and decompose leaves even at very high fungicide levels (≥500 μg/L), although less efficiently. In mixed cultures, changes in leaf decomposition reflected the response pattern of the species most tolerant in monocultures. Accordingly, the decomposition process may be safeguarded by tolerant species in combination with functional redundancy. In all fungicide treatments, however, sensitive species were displaced and interactions between fungi changed from complementarity to competition. As AH community composition determines leaves' nutritional quality for consumers, the data suggest that fungicide exposures rather induce bottom-up effects in food webs than impairments in leaf decomposition.
Collapse
Affiliation(s)
- Patrick Baudy
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Jochen P Zubrod
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, D-76829, Landau, Germany; Eußerthal Ecosystem Research Station, University of Koblenz-Landau, Birkenthalstraße 13, D-76857, Eußerthal, Germany
| | - Marco Konschak
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Nina Röder
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Thu Huyen Nguyen
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Verena C Schreiner
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Christiane Baschien
- Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Inhoffenstraße 7B, D-38124, Braunschweig, Germany
| | - Ralf Schulz
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, D-76829, Landau, Germany; Eußerthal Ecosystem Research Station, University of Koblenz-Landau, Birkenthalstraße 13, D-76857, Eußerthal, Germany
| | - Mirco Bundschuh
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, D-76829, Landau, Germany; Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Lennart Hjelms Väg 9, SWE-75007, Uppsala, Sweden.
| |
Collapse
|
8
|
Baudy P, Zubrod JP, Konschak M, Kolbenschlag S, Pollitt A, Baschien C, Schulz R, Bundschuh M. Fungal-fungal and fungal-bacterial interactions in aquatic decomposer communities: bacteria promote fungal diversity. Ecology 2021; 102:e03471. [PMID: 34260739 DOI: 10.1002/ecy.3471] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/19/2021] [Accepted: 03/15/2021] [Indexed: 11/07/2022]
Abstract
Fungi produce a variety of extracellular enzymes making recalcitrant substrates bioavailable. Thus, fungi are central for decomposition of dead organic matter such as leaf litter. Despite their ecological importance, our understanding of relationships between fungal species diversity and ecosystem functioning is limited, especially with regard to aquatic habitats. Moreover, fungal interactions with other groups of microorganisms such as bacteria are rarely investigated. This lack of information may be attributed to methodological limitations in tracking the biomass of individual fungal species in communities, impeding a detailed assessment of deviations from the overall performance expected from the sum of individual species' performances, so-called net diversity effects (NDEs). We used fungal species-specific biomolecular tools to target fungal-fungal and fungal-bacterial interactions on submerged leaves using four cosmopolitan aquatic fungal species and a stream microbial community dominated by bacteria. In microcosms, we experimentally manipulated fungal diversity and bacterial absence/presence and assessed functional performances and fungal community composition after 14 days of incubation. Fungal community data was used to evaluate NDEs on leaf colonization. The individual fungal species were functionally distinct and fungal cultures were on average more efficient than the bacterial culture. In absence of bacteria, NDEs correlated with growth rate (negatively) and genetic divergence (positively), but were predominantly negative, suggesting that higher fungal diversity led to a lower colonization success (niche overlap). In both absence and presence of bacteria, the overall functional performances of the communities were largely defined by their composition (i.e., no interactions at the functional level). In presence of bacteria, NDEs correlated with genetic divergence (positively) and were largely positive, suggesting higher fungal diversity stimulated colonization (niche complementarity). This stimulation may be driven by a bacteria-induced inhibition of fungal growth, alleviating competition among fungi. Resulting feedback loops eventually promote fungal coexistence and synergistic interactions. Nonetheless, overall functional performances are reduced compared to bacteria-free cultures. These findings highlight the necessity to conduct future studies, investigating biodiversity-ecosystem functioning relationships using artificial systems, without exclusion of key organisms naturally co-occurring in the compartment of interest. Otherwise, study outcomes might not reflect true ecological relationships and ultimately misguide conservation strategies.
Collapse
Affiliation(s)
- Patrick Baudy
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, Landau, D-76829, Germany
| | - Jochen P Zubrod
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, Landau, D-76829, Germany
- Eußerthal Ecosystem Research Station, University of Koblenz-Landau, Birkenthalstraße 13, Eußerthal, D-76857, Germany
| | - Marco Konschak
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, Landau, D-76829, Germany
| | - Sara Kolbenschlag
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, Landau, D-76829, Germany
| | - Annika Pollitt
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, Landau, D-76829, Germany
| | - Christiane Baschien
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH, Inhoffenstraße 7B, Braunschweig, D-38124, Germany
| | - Ralf Schulz
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, Landau, D-76829, Germany
- Eußerthal Ecosystem Research Station, University of Koblenz-Landau, Birkenthalstraße 13, Eußerthal, D-76857, Germany
| | - Mirco Bundschuh
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstraße 7, Landau, D-76829, Germany
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, Uppsala, SWE-75007, Sweden
| |
Collapse
|
9
|
El-Elimat T, Raja HA, Figueroa M, Al Sharie AH, Bunch RL, Oberlies NH. Freshwater Fungi as a Source of Chemical Diversity: A Review. JOURNAL OF NATURAL PRODUCTS 2021; 84:898-916. [PMID: 33662206 PMCID: PMC8127292 DOI: 10.1021/acs.jnatprod.0c01340] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
As their name indicates, freshwater fungi occur on submerged substrates in fresh water habitats. This review brings together the chemical diversity and biological activity of 199 of the 280 known freshwater fungal metabolites published from 1992 to 2020, representing at least seven structural classes, including polyketides, phenylpropanoids, terpenoids, meroterpenoids, alkaloids, polypeptides, and monosaccharides. In addition to describing what they are, where they are found, and what they do, we also discuss strategies for the collection, isolation, and identification of fungi from freshwater habitats, with the goal of enhancing chemists' knowledge of several mycological principles. We anticipate that this review will provide a springboard for future natural products studies from this fascinating but underexplored group of Ascomycota.
Collapse
Affiliation(s)
- Tamam El-Elimat
- Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Huzefa A. Raja
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| | - Mario Figueroa
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Ahmed H. Al Sharie
- Faculty of Medicine, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Rick L. Bunch
- Department of Geography, Environment, and Sustainability, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, USA
| | - Nicholas H. Oberlies
- Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, United States
| |
Collapse
|
10
|
A glance into the black box: Novel species-specific quantitative real-time PCR assays to disentangle aquatic hyphomycete community composition. FUNGAL ECOL 2019. [DOI: 10.1016/j.funeco.2019.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
11
|
Zanne AE, Abarenkov K, Afkhami ME, Aguilar-Trigueros CA, Bates S, Bhatnagar JM, Busby PE, Christian N, Cornwell WK, Crowther TW, Flores-Moreno H, Floudas D, Gazis R, Hibbett D, Kennedy P, Lindner DL, Maynard DS, Milo AM, Nilsson RH, Powell J, Schildhauer M, Schilling J, Treseder KK. Fungal functional ecology: bringing a trait-based approach to plant-associated fungi. Biol Rev Camb Philos Soc 2019; 95:409-433. [PMID: 31763752 DOI: 10.1111/brv.12570] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 10/27/2019] [Accepted: 10/31/2019] [Indexed: 12/21/2022]
Abstract
Fungi play many essential roles in ecosystems. They facilitate plant access to nutrients and water, serve as decay agents that cycle carbon and nutrients through the soil, water and atmosphere, and are major regulators of macro-organismal populations. Although technological advances are improving the detection and identification of fungi, there still exist key gaps in our ecological knowledge of this kingdom, especially related to function. Trait-based approaches have been instrumental in strengthening our understanding of plant functional ecology and, as such, provide excellent models for deepening our understanding of fungal functional ecology in ways that complement insights gained from traditional and -omics-based techniques. In this review, we synthesize current knowledge of fungal functional ecology, taxonomy and systematics and introduce a novel database of fungal functional traits (FunFun ). FunFun is built to interface with other databases to explore and predict how fungal functional diversity varies by taxonomy, guild, and other evolutionary or ecological grouping variables. To highlight how a quantitative trait-based approach can provide new insights, we describe multiple targeted examples and end by suggesting next steps in the rapidly growing field of fungal functional ecology.
Collapse
Affiliation(s)
- Amy E Zanne
- Department of Biological Sciences, George Washington University, Washington, DC, 20052, U.S.A
| | - Kessy Abarenkov
- Natural History Museum, University of Tartu, Vanemuise 46, Tartu, 51014, Estonia
| | - Michelle E Afkhami
- Department of Biology, University of Miami, Coral Gables, FL, 33146, U.S.A
| | - Carlos A Aguilar-Trigueros
- Freie Universität-Berlin, Berlin-Brandenburg Institute of Advanced Biodiversity Research, 14195, Berlin, Germany
| | - Scott Bates
- Department of Biological Sciences, Purdue University Northwest, Westville, IN, 46391, U.S.A
| | | | - Posy E Busby
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97330, U.S.A
| | - Natalie Christian
- Department of Plant Biology, University of Illinois Urbana-Champaign, Urbana, IL, 61801, U.S.A.,Department of Biology, University of Louisville, Louisville, KY 40208, U.S.A
| | - William K Cornwell
- Evolution & Ecology Research Centre, School of Biological Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Thomas W Crowther
- Department of Environmental Systems Science, Institute of Integrative Biology, ETH Zürich, 8092, Zürich, Switzerland
| | - Habacuc Flores-Moreno
- Department of Ecology, Evolution, and Behavior, and Department of Forest Resources, University of Minnesota, St. Paul, MN, 55108, U.S.A
| | - Dimitrios Floudas
- Microbial Ecology Group, Department of Biology, Lund University, Lund, Sweden
| | - Romina Gazis
- Department of Plant Pathology, Tropical Research & Education Center, University of Florida, Homestead, FL, 33031, U.S.A
| | - David Hibbett
- Biology Department, Clark University, Worcester, MA, 01610, U.S.A
| | - Peter Kennedy
- Plant & Microbial Biology, University of Minnesota, St. Paul, MN, 55108, U.S.A
| | - Daniel L Lindner
- US Forest Service, Northern Research Station, Center for Forest Mycology Research, Madison, Wisconsin, WI, 53726, U.S.A
| | - Daniel S Maynard
- Department of Environmental Systems Science, Institute of Integrative Biology, ETH Zürich, 8092, Zürich, Switzerland
| | - Amy M Milo
- Department of Biological Sciences, George Washington University, Washington, DC, 20052, U.S.A
| | - Rolf Henrik Nilsson
- University of Gothenburg, Department of Biological and Environmental Sciences, Gothenburg Global Biodiversity Centre, Box 461, 405 30, Göteborg, Sweden
| | - Jeff Powell
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, 2751, Australia
| | - Mark Schildhauer
- National Center for Ecological Analysis and Synthesis, 735 State Street, Suite 300, Santa Barbara, CA, 93101, U.S.A
| | - Jonathan Schilling
- Plant & Microbial Biology, University of Minnesota, St. Paul, MN, 55108, U.S.A
| | - Kathleen K Treseder
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA, 92697, U.S.A
| |
Collapse
|
12
|
Brighenti S, Tolotti M, Bruno MC, Wharton G, Pusch MT, Bertoldi W. Ecosystem shifts in Alpine streams under glacier retreat and rock glacier thaw: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 675:542-559. [PMID: 31030160 DOI: 10.1016/j.scitotenv.2019.04.221] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 04/10/2019] [Accepted: 04/13/2019] [Indexed: 06/09/2023]
Abstract
This review provides a detailed synthesis of the effects of glacier retreat and permafrost thaw on stream ecosystems in the European Alps. As a working framework, we present a conceptual model developed from an integration of current knowledge and understanding of the habitat and ecological shifts in Alpine streams caused by deglaciation. In our work, we depict how climate change and the loss of cryosphere trigger complex cascading effects on Alpine hydrology, as the main water sources shift from snow and glaciers to rock glaciers, groundwater, and precipitation. The associated changes in habitat conditions, such as channel stability, turbidity, temperature, nutrient loadings, and concentrations of legacy pollutants and trace elements are identified. These changes are followed by complex ecological shifts in the stream communities (microbial community, primary producers, invertebrates) and food webs, with a predicted loss of biotic diversity. Corresponding increases in taxa abundances, biomass, functional diversity, and in the complexity of food webs, are predicted to occur in the upper reaches of Alpine catchments in response to ameliorating climatic and habitat conditions. Finally, current knowledge gaps are highlighted as a basis for framing future research agendas. In particular, we call for an improved understanding of permafrost influence on Alpine headwaters, including the ecology of rock-glacier fed streams, as these streams are likely to become increasingly important for water supply in many glacier-free Alpine valleys in the near future.
Collapse
Affiliation(s)
- Stefano Brighenti
- Department of Civil, Environmental and Mechanical Engineering, University of Trento, Trento, TN, Italy; Department of Sustainable Agro-ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, TN, Italy
| | - Monica Tolotti
- Department of Sustainable Agro-ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, TN, Italy
| | - Maria Cristina Bruno
- Department of Sustainable Agro-ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, TN, Italy.
| | - Geraldene Wharton
- School of Geography, Queen Mary University of London, London, United Kingdom
| | - Martin T Pusch
- Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
| | - Walter Bertoldi
- Department of Civil, Environmental and Mechanical Engineering, University of Trento, Trento, TN, Italy
| |
Collapse
|
13
|
Koivusaari P, Tejesvi MV, Tolkkinen M, Markkola A, Mykrä H, Pirttilä AM. Fungi Originating From Tree Leaves Contribute to Fungal Diversity of Litter in Streams. Front Microbiol 2019; 10:651. [PMID: 31001228 PMCID: PMC6454979 DOI: 10.3389/fmicb.2019.00651] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 03/14/2019] [Indexed: 01/03/2023] Open
Abstract
Biomass production and decomposition are key processes in ecology, where plants are primarily responsible for production and microbes act in decomposition. Trees harbor foliar microfungi living on and inside leaf tissues, epiphytes, and endophytes, respectively. Early researchers hypothesized that all fungal endophytes are parasites or latent saprophytes, which slowly colonize the leaf tissues for decomposition. While this has been proven for some strains in the terrestrial environment, it is not known whether foliar microfungi from terrestrial origin can survive or perform decomposition in the aquatic environment. On the other hand, aquatic hyphomycetes, fungi which decompose organic material in stream environments, have been suggested to have a plant-associated life phase. Our aim was to study how much the fungal communities of leaves and litter submerged in streams overlap. Ergosterol content on litter, which is an estimator of fungal biomass, was 5-14 times higher in submerged litter than in senescent leaves, indicating active fungal colonization. Leaves generally harbored a different microbiome prior to than after submergence in streams. The Chao1 richness was significantly higher (93.7 vs. 60.7, p = 0.004) and there were more observed operational taxonomic units (OTUs) (78.3 vs. 47.4, p = 0.004) in senescent leaves than in stream-immersed litter. There were more Leotiomycetes (9%, p = 0.014) in the litter. We identified a group of 35 fungi (65%) with both plant- and water-associated lifestyles. Of these, eight taxa had no previous references to water, such as lichenicolous fungi. Six OTUs were classified within Glomeromycota, known as obligate root symbionts with no previous records from leaves. Five members of Basidiomycota, which are rare in aquatic environments, were identified in the stream-immersed litter only. Overall, our study demonstrates that foliar microfungi contribute to fungal diversity in submerged litter.
Collapse
Affiliation(s)
| | - Mysore V Tejesvi
- Ecology and Genetics, University of Oulu, Oulu, Finland.,Chain Antimicrobials Oy, Oulu, Finland
| | | | | | - Heikki Mykrä
- Freshwater Centre, Finnish Environment Institute, Oulu, Finland
| | | |
Collapse
|
14
|
Gonçalves AL, Simões S, Bärlocher F, Canhoto C. Leaf litter microbial decomposition in salinized streams under intermittency. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 653:1204-1212. [PMID: 30759560 DOI: 10.1016/j.scitotenv.2018.11.050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 11/03/2018] [Accepted: 11/04/2018] [Indexed: 06/09/2023]
Abstract
Human-induced salinization of freshwaters constitutes a growing global problem, whose consequences on streams functioning are largely unknown. Climate change projections predict enhanced evaporation, as well as an increase in extreme events and in variability of precipitation. This will result in more frequent, extended and severe drought periods that may aggravate water salinization of streams and rivers. In this study we conducted a microcosm experiment to assess the combined effects of three drought regimes - abrupt (AD), slow (SD) and very slow transition to dryness (VSD) - and three levels of salinization (0, 4, 6 g L-1 NaCl) on microbial-mediated oak leaf decomposition over ten weeks. Salinization did not affect mass loss and associated microbial respiration of colonized oak leaves but significantly reduced the biomass and eliminated the sporulating capacity of fungi. Desiccation negatively affected leaf decomposition regardless of regime. Even though microbial respiration did not react to the different treatments, lower fungal biomass, diversity, and conidial production were observed under AD; for fungal biomass these effects were amplified at higher salt concentrations (particularly at 6 g L-1). Our results indicate that effects of leaf litter desiccation depend on the rate of transition between wet and dry conditions and on the level of salt in the water. The two factors jointly affect decomposer survival and activity and, by extension, the dynamics of detrital food webs in streams.
Collapse
Affiliation(s)
- Ana Lúcia Gonçalves
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal.
| | - Sara Simões
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
| | - Felix Bärlocher
- Department of Biology, Mt. Allison University, Sackville, New Brunswick, Canada
| | - Cristina Canhoto
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
| |
Collapse
|
15
|
Cornut J, De Respinis S, Tonolla M, Petrini O, Bärlocher F, Chauvet E, Bruder A. Rapid characterization of aquatic hyphomycetes by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Mycologia 2019; 111:177-189. [PMID: 30640580 DOI: 10.1080/00275514.2018.1528129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Protein fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI--TOF MS) is a rapid, reliable, and economical method to characterize isolates of terrestrial fungi and other microorganisms. The objective of our study was to evaluate the suitability of MALDI-TOF MS for the identification of aquatic hyphomycetes, a polyphyletic group of fungi that play crucial roles in stream ecosystems. To this end, we used 34 isolates of 21 aquatic hyphomycete species whose identity was confirmed by spore morphology and internal transcribed spacer (ITS1-5.8S-ITS2 = ITS) nuc rDNA sequencing. We tested the efficiency of three protein extraction methods, including chemical and mechanical treatments using 13 different protocols, with the objective of producing high-quality MALDI-TOF mass spectra. In addition to extraction protocols, mycelium age was identified as a key parameter affecting protein extraction efficiency. The dendrogram based on mass-spectrum similarity indicated good and relevant taxonomic discrimination; the tree structure was comparable to that of the phylogram based on ITS sequences. Consequently, MALDI-TOF MS could reliably identify the isolates studied and provided greater taxonomic accuracy than classical morphological methods. MALDI-TOF MS seems suited for rapid characterization and identification of aquatic hyphomycete species.
Collapse
Affiliation(s)
- Julien Cornut
- a Laboratory of Applied Microbiology, University of Applied Sciences and Arts of Southern Switzerland , Via Mirasole 22A, 6501 Bellinzona , Switzerland.,b Institute of Earth Sciences, University of Applied Sciences and Arts of Southern Switzerland, Trevano Campus , 6952 Canobbio , Switzerland
| | - Sophie De Respinis
- a Laboratory of Applied Microbiology, University of Applied Sciences and Arts of Southern Switzerland , Via Mirasole 22A, 6501 Bellinzona , Switzerland
| | - Mauro Tonolla
- a Laboratory of Applied Microbiology, University of Applied Sciences and Arts of Southern Switzerland , Via Mirasole 22A, 6501 Bellinzona , Switzerland.,c Microbial Ecology Laboratory, Microbiology Unit, Department of Botany and Plant Biology , University of Geneva , Switzerland
| | | | - Felix Bärlocher
- e Department of Biology , Mount Allison University , Sackville , News Brunswick E4L1G7, Canada
| | - Eric Chauvet
- f EcoLab, Université de Toulouse , CNRS, UPS, INPT, 31062 Toulouse , France
| | - Andreas Bruder
- a Laboratory of Applied Microbiology, University of Applied Sciences and Arts of Southern Switzerland , Via Mirasole 22A, 6501 Bellinzona , Switzerland.,b Institute of Earth Sciences, University of Applied Sciences and Arts of Southern Switzerland, Trevano Campus , 6952 Canobbio , Switzerland
| |
Collapse
|
16
|
Quality and quantity of leaf litter: Both are important for feeding preferences and growth of an aquatic shredder. PLoS One 2018; 13:e0208272. [PMID: 30540796 PMCID: PMC6291097 DOI: 10.1371/journal.pone.0208272] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/14/2018] [Indexed: 11/19/2022] Open
Abstract
The study of leaf litter as a resource for shredders has emerged as a key topic in trophic links in ecology. However, thus far, most studies have emphasized the leaf quality as one of the main determinants of shredder behaviour and growth without simultaneously considering the leaf quantity availability. Nevertheless, the combined effects of leaf quantity and quality on shredder behaviour and growth is particularly crucial to further understand how ecosystem functioning may respond to the increasing flow intermittency due to climate change. In this study, we explore how changes in the leaf litter quality and quantity influence the feeding preferences and growth of an invertebrate shredder (Potamophylax latipennis). To do so, we used black poplar leaves conditioned in two streams with different flow regimens as a food resource. Afterwards, using a microcosm approach, we offered leaf discs that varied in terms of leaf quantity and quality to P. latipennis. Our results showed that flow intermittency had a negative effect on the quality of the food resource, and a lower quality had a negative effect on the consumption and growth rates of P. latipennis. Furthermore, we found that P. latipennis fed selectively on higher quality leaves even though the availability (quantity) of this resource was lower. In the context of climate change, with higher aridity/drier conditions/scenarios, our findings suggest that a decrease in the availability (quantity) of high-quality resources could potentially threaten links in global fluvial food webs and thus threaten ecosystem functioning.
Collapse
|
17
|
A High-Resolution Time Series Reveals Distinct Seasonal Patterns of Planktonic Fungi at a Temperate Coastal Ocean Site (Beaufort, North Carolina, USA). Appl Environ Microbiol 2018; 84:AEM.00967-18. [PMID: 30143506 DOI: 10.1128/aem.00967-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 08/17/2018] [Indexed: 11/20/2022] Open
Abstract
There is a growing awareness of the ecological and biogeochemical importance of fungi in coastal marine systems. While highly diverse fungi have been discovered in these marine systems, still, little is known about their seasonality and associated drivers in coastal waters. Here, we examined fungal communities over 3 years of weekly sampling at a dynamic, temperate coastal site (Pivers Island Coastal Observatory [PICO], Beaufort, NC, USA). Fungal 18S rRNA gene abundance, operational taxonomic unit (OTU) richness, and Shannon's diversity index values exhibited prominent seasonality. Fungal 18S rRNA gene copies peaked in abundance during the summer and fall, with positive correlations with chlorophyll a, SiO4, and oxygen saturation. Diversity (measured using internal transcribed spacer [ITS] libraries) was highest during winter and lowest during summer; it was linked to temperature, pH, chlorophyll a, insolation, salinity, and dissolved inorganic carbon (DIC). Fungal communities derived from ITS libraries were dominated throughout the year by Ascomycota, with contributions from Basidiomycota, Chytridiomycota, and Mucoromycotina, and their seasonal patterns linked to water temperature, light, and the carbonate system. Network analysis revealed that while cooccurrence and exclusion existed within fungus networks, exclusion dominated the fungus-and-phytoplankton network, in contrast with reported pathogenic and nutritional interactions between marine phytoplankton and fungi. Compared with the seasonality of bacterial communities in the same samples, the timing, extent, and associated environmental variables for fungi community are unique. These results highlight the fungal seasonal dynamics in coastal water and improve our understanding of the ecology of planktonic fungi.IMPORTANCE Coastal fungal dynamics were long assumed to be due to terrestrial inputs; here, a high-resolution time series reveals strong, repeating annual patterns linked to in situ environmental conditions, arguing for a resident coastal fungal community shaped by environmental factors. These seasonal patterns do, however, differ from those observed in the bacterioplankton at the same site; e.g., fungal diversity peaks in winter, whereas bacterial diversity maxima occur in the spring and fall. While the dynamics of these communities are linked to water temperature and insolation, fungi are also influenced by the carbonate system (pH and DIC). As both fungi and heterotrophic bacteria are thought to be key organic-material metabolizers, differences in their environmental drivers may offer clues as to which group dominates secondary production at this dynamic site. Overall, this study suggests the unique ecological roles of mycoplankton and their potentially broad niche complementarities to other microbial groups in the coastal ocean.
Collapse
|
18
|
Seena S, Marvanová L, Letourneau A, Bärlocher F. Articulospora - Phylogeny vs morphology. Fungal Biol 2018; 122:965-976. [PMID: 30227932 DOI: 10.1016/j.funbio.2018.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 05/31/2018] [Accepted: 06/08/2018] [Indexed: 01/29/2023]
Abstract
The taxonomy of the aquatic hyphomycete genus Articulospora (Ascomycota, Pezizomycotima, Leotiales, Helotiaceae) is based on the morphology of the generative phase of its lifecycle. The type species is Articulospora tetracladia, which is distributed worldwide. Its most frequent populations in nature have dimorphic conidia, differing by the extent of conidial branching (i.e., one or two levels of branching). Some strains, stable in culture, produce exclusively conidia of one type. With the molecular analyses employed here and the relatively low number of available isolates (20), separation based on branching of conidia has not been fully supported. Therefore we propose to retain the broad concept of A. tetracladia with dimorphic conidia. Among the three gene sequences tested as potential barcodes, the internal transcribed spacer (ITS) gene was the most promising region. All strains yielded amplifiable DNA which provided adequate resolution, according to accepted ranges in inter/intraspecific differences, to differentiate among the three Articulospora and two Fontanospora species that were tested (Articulospora atra, Articulospora proliferata, A. tetracladia, Fontanospora eccentrica, Fontanospora fusiramosa). D1/D2 primers also permitted amplification in all strains, however without much resolution. Amplification of the COX1 gene sequence was least consistent.
Collapse
Affiliation(s)
- Sahadevan Seena
- MARE-Marine and Environmental Sciences Centre, University of Coimbra, PT-3004-517, Coimbra, Portugal
| | - Ludmila Marvanová
- Czech Collection of Microorganisms, Faculty of Science, Masaryk University, 625 00, Brno, Czech Republic
| | - Allan Letourneau
- Department of Chemistry, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada
| | - Felix Bärlocher
- Department of Biology, Mount Allison University, Sackville, NB, E4L 1G7, Canada.
| |
Collapse
|
19
|
|
20
|
Canhoto C, Simões S, Gonçalves AL, Guilhermino L, Bärlocher F. Stream salinization and fungal-mediated leaf decomposition: A microcosm study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 599-600:1638-1645. [PMID: 28535592 DOI: 10.1016/j.scitotenv.2017.05.101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 05/11/2017] [Accepted: 05/11/2017] [Indexed: 06/07/2023]
Abstract
Salinization is of major global concern due to its effect on stream biota, and ecosystem functions and services. In small streams, litter decomposition is a key ecosystem-level process driven by decomposers, mainly fungi (aquatic hyphomycetes), which link litter and invertebrates. Here we assessed the effects of an environmentally relevant range of salt additions (0, 2, 4, 8, 16gL-1 NaCl) on (1) fungal growth and species-specific reproductive output and (2) fungal mediated-decomposition of Quercus robur leaves. Growth rates of eight out of nine species of aquatic hyphomycetes were negatively affected by salinity at concentrations ≥4gL-1. EC50s were species-specific and ≥7.80gL-1. Distinct thresholds were observed for reproduction: only five species sporulated at 2gL-1, and a single one (Flagellospora curta) sporulated at 4 and 8gL-1 NaCl. Based on these results, we evaluated if tolerant fungal assemblages, with increasingly fewer species (9, 5, 1), were able to maintain similar functional functions and processes at the different salt levels. No significant differences were found in oak mass loss or sporulation rates at 0 or 2gL-1 NaCl; a clear inhibition of both parameters was observed at the highest concentrations (i.e., 4 and 8gL-1 NaCl). Different dominance patterns in multi-species fungal assemblages may determine bottom-up impacts on the stream food webs through effects on detritivore feeding preferences. Specific growth rate, characterized by RNA concentration, was higher in the single species, at the highest salt-concentration, and lower in the 9-species assemblage. Respiration was almost 2-times higher in mixed assemblages without added salt. Under salt-contamination, trade-offs between growth and sporulation seem to guarantee high levels of fungal growth and decomposition, particularly in multi-species assemblages. In the presence of salt contamination, aquatic hyphomycetes, even at reduced diversity, remain important drivers of leaf decomposition and ensure organic matter recycling.
Collapse
Affiliation(s)
- Cristina Canhoto
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal.
| | - Sara Simões
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
| | - Ana Lúcia Gonçalves
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal
| | - Lúcia Guilhermino
- ICBAS & CIIMAR, University of Porto, CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, Research Group of Ecotoxicology, Stress Ecology and Environmental Health, ICBAS - Institute of Biomedical Sciences of Abel Salazar, Department of Population Studies, Laboratory of Ecotoxicology, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Felix Bärlocher
- Department of Biology, Mt. Allison University, Sackville, New Brunswick E4L1G7, Canada
| |
Collapse
|
21
|
Brosed M, Jabiol J, Gessner MO. Nutrient stoichiometry of aquatic hyphomycetes: Interstrain variation and ergosterol conversion factors. FUNGAL ECOL 2017. [DOI: 10.1016/j.funeco.2017.04.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
|
22
|
Duarte S, Cássio F, Pascoal C, Bärlocher F. Taxa-area relationship of aquatic fungi on deciduous leaves. PLoS One 2017; 12:e0181545. [PMID: 28719634 PMCID: PMC5515451 DOI: 10.1371/journal.pone.0181545] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 07/03/2017] [Indexed: 02/01/2023] Open
Abstract
One of the fundamental patterns in macroecology is the increase in the number of observed taxa with size of sampled area. For microbes, the shape of this relationship remains less clear. The current study assessed the diversity of aquatic fungi, by the traditional approach based on conidial morphology (captures reproducing aquatic hyphomycetes) and next generation sequencing (NGS; captures other fungi as well), on graded sizes of alder leaves (0.6 to 13.6 cm2). Leaves were submerged in two streams in geographically distant locations: the Oliveira Stream in Portugal and the Boss Brook in Canada. Decay rates of alder leaves and fungal sporulation rates did not differ between streams. Fungal biomass was higher in Boss Brook than in Oliveira Stream, and in both streams almost 100% of the reads belonged to active fungal taxa. In general, larger leaf areas tended to harbour more fungi, but these findings were not consistent between techniques. Morphospecies-based diversity increased with leaf area in Boss Brook, but not in Oliveira Stream; metabarcoding data showed an opposite trend. The higher resolution of metabarcoding resulted in steeper taxa-accumulation curves than morphospecies-based assessments (fungal conidia morphology). Fungal communities assessed by metabarcoding were spatially structured by leaf area in both streams. Metabarcoding promises greater resolution to assess biodiversity patterns in aquatic fungi and may be more accurate for assessing taxa-area relationships and local to global diversity ratios.
Collapse
Affiliation(s)
- Sofia Duarte
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga, Portugal
- * E-mail:
| | - Fernanda Cássio
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga, Portugal
- Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Braga, Portugal
| | - Cláudia Pascoal
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga, Portugal
- Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Braga, Portugal
| | - Felix Bärlocher
- Department of Biology, Mount Allison University, Sackville, New Brunswick, Canada
| |
Collapse
|
23
|
|
24
|
Feckler A, Schrimpf A, Bundschuh M, Bärlocher F, Baudy P, Cornut J, Schulz R. Quantitative real-time PCR as a promising tool for the detection and quantification of leaf-associated fungal species - A proof-of-concept using Alatospora pulchella. PLoS One 2017; 12:e0174634. [PMID: 28384166 PMCID: PMC5383034 DOI: 10.1371/journal.pone.0174634] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 03/13/2017] [Indexed: 11/18/2022] Open
Abstract
Traditional methods to identify aquatic hyphomycetes rely on the morphology of released conidia, which can lead to misidentifications or underestimates of species richness due to convergent morphological evolution and the presence of non-sporulating mycelia. Molecular methods allow fungal identification irrespective of the presence of conidia or their morphology. As a proof-of-concept, we established a quantitative real-time polymerase chain reaction (qPCR) assay to accurately quantify the amount of DNA as a proxy for the biomass of an aquatic hyphomycete species (Alatospora pulchella). Our study showed discrimination even among genetically closely-related species, with a high sensitivity and a reliable quantification down to 9.9 fg DNA (3 PCR forming units; LoD) and 155.0 fg DNA (47 PCR forming units; LoQ), respectively. The assay's specificity was validated for environmental samples that harboured diverse microbial communities and likely contained PCR-inhibiting substances. This makes qPCR a promising tool to gain deeper insights into the ecological roles of aquatic hyphomycetes and other microorganisms.
Collapse
Affiliation(s)
- Alexander Feckler
- Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anne Schrimpf
- Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany
| | - Mirco Bundschuh
- Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Felix Bärlocher
- Department of Biology, Mt. Allison University, Sackville, Canada
| | - Patrick Baudy
- Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany
| | - Julien Cornut
- Laboratoire Interdisciplinaire des Environnements Continentaux, UMR CNRS 7360, Université de Lorraine, Metz, France
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, Germany
- MARE–Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | - Ralf Schulz
- Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany
| |
Collapse
|
25
|
Tlili A, Jabiol J, Behra R, Gil-Allué C, Gessner MO. Chronic Exposure Effects of Silver Nanoparticles on Stream Microbial Decomposer Communities and Ecosystem Functions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2447-2455. [PMID: 28085256 DOI: 10.1021/acs.est.6b05508] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
With the accelerated use of silver nanoparticles (AgNP) in commercial products, streams will increasingly serve as recipients of, and repositories for, AgNP. This raises concerns about the potential toxicity of these nanomaterials in the environment. Here we aimed to assess the impacts of chronic AgNP exposure on the metabolic activities and community structure of fungal and bacterial plant litter decomposers as central players in stream ecosystems. Minimal variation in the size and surface charge of AgNP indicated that nanoparticles were rather stable during the experiment. Five days of exposure to 0.05 and 0.5 μM AgNP in microcosms shifted bacterial community structure but had no effect on a suite of microbial metabolic activities, despite silver accumulation in the decomposing leaf litter. After 25 days, however, a broad range of microbial endpoints, as well as rates of litter decomposition, were strongly affected. Declines matched with the total silver concentration in the leaves and were accompanied by changes in fungal and bacterial community structure. These results highlight a distinct sensitivity of litter-associated microbial communities in streams to chronic AgNP exposure, with effects on both microbial functions and community structure resulting in notable ecosystem consequences through impacts on litter decomposition and further biogeochemical processes.
Collapse
Affiliation(s)
- Ahmed Tlili
- Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) , 16775 Stechlin, Germany
- Department of Environmental Toxicology, Eawag: Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf, Switzerland
| | - Jérémy Jabiol
- Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) , 16775 Stechlin, Germany
| | - Renata Behra
- Department of Environmental Toxicology, Eawag: Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf, Switzerland
| | - Carmen Gil-Allué
- Department of Environmental Toxicology, Eawag: Swiss Federal Institute of Aquatic Science and Technology , 8600 Dübendorf, Switzerland
| | - Mark O Gessner
- Department of Experimental Limnology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) , 16775 Stechlin, Germany
- Department of Ecology, Berlin Institute of Technology (TU Berlin) , 10623 Berlin, Germany
| |
Collapse
|
26
|
Jankowiak R, Bilański P, Paluch J, Kołodziej Z. Fungi associated with dieback of Abies alba seedlings in naturally regenerating forest ecosystems. FUNGAL ECOL 2016. [DOI: 10.1016/j.funeco.2016.08.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
27
|
Vacher C, Hampe A, Porté AJ, Sauer U, Compant S, Morris CE. The Phyllosphere: Microbial Jungle at the Plant–Climate Interface. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2016. [DOI: 10.1146/annurev-ecolsys-121415-032238] [Citation(s) in RCA: 229] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Arndt Hampe
- BIOGECO, INRA, Univ. Bordeaux, 33610 Cestas, France
| | | | - Ursula Sauer
- Bioresources Unit, Department of Health and Environment, AIT Austrian Institute of Technology GmbH, 3430 Tulln, Austria
| | - Stéphane Compant
- Bioresources Unit, Department of Health and Environment, AIT Austrian Institute of Technology GmbH, 3430 Tulln, Austria
| | - Cindy E. Morris
- INRA, Unité de Recherche de Pathologie Végétale, 84143 Montfavet, France
| |
Collapse
|
28
|
Mustonen KR, Mykrä H, Louhi P, Markkola A, Tolkkinen M, Huusko A, Alioravainen N, Lehtinen S, Muotka T. Sediments and flow have mainly independent effects on multitrophic stream communities and ecosystem functions. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:2116-2129. [PMID: 27755727 DOI: 10.1890/15-1841.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 02/11/2016] [Accepted: 03/04/2016] [Indexed: 06/06/2023]
Abstract
Stream ecosystems are affected by multiple abiotic stressors, and species responses to simultaneous stressors may differ from those predicted based on single-stressor responses. Using 12 semi-natural stream channels, we examined the individual and interactive effects of flow level (low or high flow) and addition of fine sediments (grain size <2 mm) on key ecosystem processes (leaf breakdown, algal biomass accrual) and benthic macroinvertebrate and fungal communities. Both stressors had mostly independent effects on biological responses, with sand addition being the more influential of the two. Sand addition decreased algal biomass and microbe-mediated leaf breakdown significantly, whereas invertebrate shredder-mediated breakdown only responded to flow level. Macroinvertebrate community composition responded significantly to both stressors. Fungal biomass decreased and shredder abundance increased when sand was added; thus, organisms at different trophic levels can exhibit highly variable responses to the same stressor. Terrestrial endophytic fungi were abundant in low-flow flumes where leaf mass loss was also highest, indicating that terrestrial endophytes may contribute importantly to leaf decomposition in the aquatic environment. Leaf breakdown rates depended on the identity and abundance of the dominant decomposer species, suggesting that the effects of anthropogenic activities on ecosystem processes may be driven by changes in the abundance of a few key species. The few observed interactive effects were all antagonistic (i.e., less than the sum of the individual effects); for example, increased flow stimulated algal biomass accumulation but this effect was largely cancelled by sand. While our finding that sand and stream flow did not have strong synergistic effects can be considered reassuring for management, future experiments should manipulate these and other human stressors in experiments that run for much longer periods, thus focusing on the long-term impacts of multiple simultaneously operating stressors.
Collapse
Affiliation(s)
- Kaisa-Riikka Mustonen
- Thule Institute, University of Oulu, P.O. Box 7300, FI-90014, Oulu, Finland.
- Department of Ecology, University of Oulu, P.O. Box 8000, FI-90014, Oulu, Finland.
| | - Heikki Mykrä
- Thule Institute, University of Oulu, P.O. Box 7300, FI-90014, Oulu, Finland
- Finnish Environment Institute (SYKE), Freshwater Centre, P.O. Box 413, FI-90014, Oulu, Finland
| | - Pauliina Louhi
- Department of Ecology, University of Oulu, P.O. Box 8000, FI-90014, Oulu, Finland
| | - Annamari Markkola
- Department of Ecology, University of Oulu, P.O. Box 8000, FI-90014, Oulu, Finland
| | - Mikko Tolkkinen
- Finnish Environment Institute (SYKE), Freshwater Centre, P.O. Box 413, FI-90014, Oulu, Finland
| | - Ari Huusko
- Natural Resources Institute Finland, Manamansalontie 90, FI-88300, Paltamo, Finland
| | - Nico Alioravainen
- Department of Ecology, University of Oulu, P.O. Box 8000, FI-90014, Oulu, Finland
| | - Sirkku Lehtinen
- Department of Ecology, University of Oulu, P.O. Box 8000, FI-90014, Oulu, Finland
| | - Timo Muotka
- Department of Ecology, University of Oulu, P.O. Box 8000, FI-90014, Oulu, Finland
| |
Collapse
|
29
|
Comeau AM, Vincent WF, Bernier L, Lovejoy C. Novel chytrid lineages dominate fungal sequences in diverse marine and freshwater habitats. Sci Rep 2016; 6:30120. [PMID: 27444055 PMCID: PMC4957111 DOI: 10.1038/srep30120] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/29/2016] [Indexed: 11/08/2022] Open
Abstract
In aquatic environments, fungal communities remain little studied despite their taxonomic and functional diversity. To extend the ecological coverage of this group, we conducted an in-depth analysis of fungal sequences within our collection of 3.6 million V4 18S rRNA pyrosequences originating from 319 individual marine (including sea-ice) and freshwater samples from libraries generated within diverse projects studying Arctic and temperate biomes in the past decade. Among the ~1.7 million post-filtered reads of highest taxonomic and phylogenetic quality, 23,263 fungal sequences were identified. The overall mean proportion was 1.35%, but with large variability; for example, from 0.01 to 59% of total sequences for Arctic seawater samples. Almost all sample types were dominated by Chytridiomycota-like sequences, followed by moderate-to-minor contributions of Ascomycota, Cryptomycota and Basidiomycota. Species and/or strain richness was high, with many novel sequences and high niche separation. The affinity of the most common reads to phytoplankton parasites suggests that aquatic fungi deserve renewed attention for their role in algal succession and carbon cycling.
Collapse
Affiliation(s)
- André M. Comeau
- Institut de Biologie Intégrative et des Systèmes (IBIS) and Centre d’Étude de la Forêt (CEF), Université Laval, Québec, Canada
| | - Warwick F. Vincent
- Centre d’Études Nordiques (CEN), Takuvik Joint International Laboratory (CNRS UMI-3376) and Département de Biologie, Université Laval, Québec, Canada
| | - Louis Bernier
- Institut de Biologie Intégrative et des Systèmes (IBIS) and Centre d’Étude de la Forêt (CEF), Université Laval, Québec, Canada
| | - Connie Lovejoy
- Institut de Biologie Intégrative et des Systèmes (IBIS), Takuvik Joint International Laboratory (CNRS UMI-3376) and Département de Biologie, Université Laval, Québec, Canada
| |
Collapse
|
30
|
Ghate SD, Sridhar KR. Diurnal periodicity of conidia of aquatic hyphomycetes in water and entrapment on latex-coated slides in two South Indian streams. Mycology 2016; 7:88-97. [PMID: 30123620 PMCID: PMC6059061 DOI: 10.1080/21501203.2016.1196759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 05/28/2016] [Indexed: 10/26/2022] Open
Abstract
Aquatic hyphomycete conidial trapping efficiency by the banyan (F. benghalensis L.) latex-coated glass slides was tested diurnally (3 h intervals) in the Western Ghats (Sampaje) and west coast (Konaje) streams in relation to abiotic factors (humidity, air temperature and water temperature). The conidial trapping efficiency of latex-coated slides was compared with plain glass slides and drift conidia in water. Three methods of assessment showed higher species richness, conidial richness and diversity in Sampaje than in Konaje stream. In both streams, species richness, conidial richness and diversity in latex-coated slides were the highest followed by conidia in water and plain slides. Three-way ANOVA revealed significant differences in overall species and conidial richness between the streams, sampling methods and time of sampling (p < 0.001). Multiple comparisons by Holm-Sidak test revealed significant differences in overall species and conidial richness between Sampaje and Konaje (p < 0.001); latex-coated slides and plain slides (p < 0.001); latex-coated slides and water filtration (p < 0.001); plain slides and water filtration (p < 0.001). Total species, total conidia and diversity assessed by the three methods peaked during 12 am-3 am in Sampaje stream, while during 3 am-6 am in Konaje stream. Cooler conditions due to relatively low water temperature favoured higher diversity of aquatic hyphomycetes in Sampaje than in Konaje stream. The three methods employed in the present study were not biased towards scolecoid or stauroid conidia. The top five species in both streams was composed of both types of conidia corroborating earlier annual or biannual studies in Konaje and Sampaje streams. Thus, assessment of population of aquatic hyphomycetes using banyan latex-coated slides will be advantageous over plain slides and drift conidia in streams.
Collapse
Affiliation(s)
- Sudeep D. Ghate
- Department of Biosciences, Mangalore University, Mangalore, India
| | | |
Collapse
|
31
|
Duarte S, Bärlocher F, Pascoal C, Cássio F. Biogeography of aquatic hyphomycetes: Current knowledge and future perspectives. FUNGAL ECOL 2016. [DOI: 10.1016/j.funeco.2015.06.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
32
|
|
33
|
|