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Duperron S, Halary S, Bouly JP, Roussel T, Hugoni M, Bruto M, Oger PM, Duval C, Woo A, Jézéquel D, Ader M, Leboulanger C, Agogué H, Grossi V, Troussellier M, Bernard C. Transcriptomic insights into the dominance of two phototrophs throughout the water column of a tropical hypersaline-alkaline crater lake (Dziani Dzaha, Mayotte). Front Microbiol 2024; 15:1368523. [PMID: 38741748 PMCID: PMC11089139 DOI: 10.3389/fmicb.2024.1368523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 04/08/2024] [Indexed: 05/16/2024] Open
Abstract
Saline-alkaline lakes often shelter high biomasses despite challenging conditions, owing to the occurrence of highly adapted phototrophs. Dziani Dzaha (Mayotte) is one such lake characterized by the stable co-dominance of the cyanobacterium Limnospira platensis and the picoeukaryote Picocystis salinarum throughout its water column. Despite light penetrating only into the uppermost meter, the prevailing co-dominance of these species persists even in light- and oxygen-deprived zones. Here, a depth profile of phototrophs metatranscriptomes, annotated using genomic data from isolated strains, is employed to identify expression patterns of genes related to carbon processing pathways including photosynthesis, transporters and fermentation. The findings indicate a prominence of gene expression associated with photosynthesis, with a peak of expression around 1 m below the surface, although the light intensity is very low and only red and dark red wavelengths can reach it, given the very high turbidity linked to the high biomass of L. platensis. Experiments on strains confirmed that both species do grow under these wavelengths, at rates comparable to those obtained under white light. A decrease in the expression of photosynthesis-related genes was observed in L. platensis with increasing depth, whereas P. salinarum maintained a very high pool of psbA transcripts down to the deepest point as a possible adaptation against photodamage, in the absence and/or very low levels of expression of genes involved in protection. In the aphotic/anoxic zone, expression of genes involved in fermentation pathways suggests active metabolism of reserve or available dissolved carbon compounds. Overall, L. platensis seems to be adapted to the uppermost water layer, where it is probably maintained thanks to gas vesicles, as evidenced by high expression of the gvpA gene. In contrast, P. salinarum occurs at similar densities throughout the water column, with a peak in abundance and gene expression levels which suggests a better adaptation to lower light intensities. These slight differences may contribute to limited inter-specific competition, favoring stable co-dominance of these two phototrophs.
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Affiliation(s)
- Sébastien Duperron
- UMR 7245 MCAM, Muséum National d’Histoire Naturelle – CNRS, Paris, France
| | - Sébastien Halary
- UMR 7245 MCAM, Muséum National d’Histoire Naturelle – CNRS, Paris, France
| | - Jean-Pierre Bouly
- UMR 7245 MCAM, Muséum National d’Histoire Naturelle – CNRS, Paris, France
| | - Théotime Roussel
- UMR 7245 MCAM, Muséum National d’Histoire Naturelle – CNRS, Paris, France
| | - Myléne Hugoni
- Université Claude Bernard Lyon 1, CNRS, INSA de Lyon, UMR 5240 Microbiologie Adaptation et Pathogénie, University of Lyon, Villeurbanne, France
- Institut Universitaire de France, Paris, France
| | - Maxime Bruto
- Anses, UMR Mycoplasmoses Animales, VetAgro Sup, Université de Lyon, Marcy-l’Étoile, France
| | - Philippe M. Oger
- Université Claude Bernard Lyon 1, CNRS, INSA de Lyon, UMR 5240 Microbiologie Adaptation et Pathogénie, University of Lyon, Villeurbanne, France
| | - Charlotte Duval
- UMR 7245 MCAM, Muséum National d’Histoire Naturelle – CNRS, Paris, France
| | - Anthony Woo
- Pôle Analyse de Données UAR 2700 2AD, Muséum National d’Histoire Naturelle, Paris, France
| | - Didier Jézéquel
- Institut de Physique du Globe de Paris, Université de Paris Cité, CNRS, Paris, France
- UMR CARRTEL, INRAE-USMB, Thonon-les-Bains, France
| | - Magali Ader
- Institut de Physique du Globe de Paris, Université de Paris Cité, CNRS, Paris, France
- UMR CARRTEL, INRAE-USMB, Thonon-les-Bains, France
| | | | - Hélène Agogué
- Littoral Environnement et Sociétés, UMR 7266, CNRS La Rochelle Université, La Rochelle, France
| | - Vincent Grossi
- LGL-TPE, UMR 5276, CNRS, ENSL, Université Claude Bernard Lyon 1, Villeurbanne, France
| | | | - Cécile Bernard
- UMR 7245 MCAM, Muséum National d’Histoire Naturelle – CNRS, Paris, France
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2
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Bruto M, Oger PM, Got P, Bernard C, Melayah D, Cloarec LA, Duval C, Escalas A, Duperron S, Guigard L, Leboulanger C, Ader M, Sarazin G, Jézéquel D, Agogué H, Troussellier M, Hugoni M. Phytoplanktonic species in the haloalkaline Lake Dziani Dzaha select their archaeal microbiome. Mol Ecol 2023; 32:6824-6838. [PMID: 37901963 DOI: 10.1111/mec.17179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 09/18/2023] [Accepted: 10/09/2023] [Indexed: 10/31/2023]
Abstract
Microorganisms are key contributors of aquatic biogeochemical cycles but their microscale ecology remains largely unexplored, especially interactions occurring between phytoplankton and microorganisms in the phycosphere, that is the region immediately surrounding phytoplankton cells. The current study aimed to provide evidence of the phycosphere taking advantage of a unique hypersaline, hyperalkaline ecosystem, Lake Dziani Dzaha (Mayotte), where two phytoplanktonic species permanently co-dominate: a cyanobacterium, Arthrospira fusiformis, and a green microalga, Picocystis salinarum. To assay phycospheric microbial diversity from in situ sampling, we set up a flow cytometry cell-sorting methodology for both phytoplanktonic populations, coupled with metabarcoding and comparative microbiome diversity. We focused on archaeal communities as they represent a non-negligible part of the phycospheric diversity, however their role is poorly understood. This work is the first which successfully explores in situ archaeal diversity distribution showing contrasted phycospheric compositions, with P. salinarum phycosphere notably enriched in Woesearchaeales OTUs while A. fusiformis phycosphere was enriched in methanogenic lineages affiliated OTUs such as Methanomicrobiales or Methanofastidiosales. Most archaeal OTUs, including Woesearchaeales considered in literature as symbionts, were either ubiquitous or specific of the free-living microbiome (i.e. present in the 3-0.2 μm fraction). Seminally, several archaeal OTUs were enriched from the free-living microbiome to the phytoplankton phycospheres, suggesting (i) either the inhibition or decrease of other OTUs, or (ii) the selection of specific OTUs resulting from the physical influence of phytoplanktonic species on surrounding Archaea.
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Affiliation(s)
- Maxime Bruto
- VetAgro Sup, Anses, UMR Mycoplasmoses Animales, Marcy l'Etoile, France
| | - Philippe M Oger
- Universite Claude Bernard Lyon 1, INSA Lyon, CNRS, UMR 5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France
| | - Patrice Got
- MARBEC, Univ Montpellier, IRD, CNRS, Ifremer, Sète, France
| | - Cécile Bernard
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM) MNHN-CNRS, Muséum National d'Histoire Naturelle, Paris Cedex 05, France
| | - Delphine Melayah
- Universite Claude Bernard Lyon 1, INSA Lyon, CNRS, UMR 5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France
| | - Lilian A Cloarec
- Universite Claude Bernard Lyon 1, INSA Lyon, CNRS, UMR 5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France
| | - Charlotte Duval
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM) MNHN-CNRS, Muséum National d'Histoire Naturelle, Paris Cedex 05, France
| | - Arthur Escalas
- MARBEC, Univ Montpellier, IRD, CNRS, Ifremer, Sète, France
| | - Sébastien Duperron
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM) MNHN-CNRS, Muséum National d'Histoire Naturelle, Paris Cedex 05, France
| | - Ludivine Guigard
- Universite Claude Bernard Lyon 1, INSA Lyon, CNRS, UMR 5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France
| | | | - Magali Ader
- Institut de Physique du Globe de Paris, Université Paris Cité, Paris, France
| | - Gerard Sarazin
- Institut de Physique du Globe de Paris, Université Paris Cité, Paris, France
| | - Didier Jézéquel
- Institut de Physique du Globe de Paris, Université Paris Cité, Paris, France
- UMR CARRTEL, INRAE-USMB, Thonon, France
| | - Hélène Agogué
- LIENSs, UMR7266, La Rochelle Université - CNRS, La Rochelle, France
| | | | - Mylène Hugoni
- Universite Claude Bernard Lyon 1, INSA Lyon, CNRS, UMR 5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France
- Institut Universitaire de France (IUF), Paris, France
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Mouillot D, Derminon S, Mariani G, Senina I, Fromentin JM, Lehodey P, Troussellier M. Industrial fisheries have reversed the carbon sequestration by tuna carcasses into emissions. Glob Chang Biol 2023; 29:5062-5074. [PMID: 37401407 DOI: 10.1111/gcb.16823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 03/13/2023] [Accepted: 04/30/2023] [Indexed: 07/05/2023]
Abstract
To limit climate warming to 2°C above preindustrial levels, most economic sectors will need a rapid transformation toward a net zero emission of CO2 . Tuna fisheries is a key food production sector that burns fossil fuel to operate but also reduces the deadfall of large-bodied fish so the capacity of this natural carbon pump to deep sea. Yet, the carbon balance of tuna populations, so the net difference between CO2 emission due to industrial exploitation and CO2 sequestration by fish deadfall after natural mortality, is still unknown. Here, by considering the dynamics of two main contrasting tuna species (Katsuwonus pelamis and Thunnus obesus) across the Pacific since the 1980s, we show that most tuna populations became CO2 sources instead of remaining natural sinks. Without considering the supply chain, the main factors associated with this shift are exploitation rate, transshipment intensity, fuel consumption, and climate change. Our study urges for a better global ocean stewardship, by curbing subsidies and limiting transshipment in remote international waters, to quickly rebuild most pelagic fish stocks above their target management reference points and reactivate a neglected carbon pump toward the deep sea as an additional Nature Climate Solution in our portfolio. Even if this potential carbon sequestration by surface unit may appear low compared to that of coastal ecosystems or tropical forests, the ocean covers a vast area and the sinking biomass of dead vertebrates can sequester carbon for around 1000 years in the deep sea. We also highlight the multiple co-benefits and trade-offs from engaging the industrial fisheries sector with carbon neutrality.
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Affiliation(s)
- David Mouillot
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
- Institut Universitaire de France, IUF, Paris, France
| | - Suzie Derminon
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique et Evolution, Gif-sur-Yvette, France
| | - Gaël Mariani
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
| | - Inna Senina
- Satellite Oceanography Division, CLS, Toulouse, France
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4
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Durfort A, Mariani G, Tulloch V, Savoca MS, Troussellier M, Mouillot D. Recovery of carbon benefits by overharvested baleen whale populations is threatened by climate change. Proc Biol Sci 2022; 289:20220375. [PMID: 36321488 PMCID: PMC9627705 DOI: 10.1098/rspb.2022.0375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 10/10/2022] [Indexed: 12/03/2022] Open
Abstract
Despite the importance of marine megafauna on ecosystem functioning, their contribution to the oceanic carbon cycle is still poorly known. Here, we explored the role of baleen whales in the biological carbon pump across the southern hemisphere based on the historical and forecasted abundance of five baleen whale species. We modelled whale-mediated carbon sequestration through the sinking of their carcasses after natural death. We provide the first temporal dynamics of this carbon pump from 1890 to 2100, considering both the effects of exploitation and climate change on whale populations. We reveal that at their pre-exploitation abundance, the five species of southern whales could sequester 4.0 × 105 tonnes of carbon per year (tC yr-1). This estimate dropped to 0.6 × 105 tC yr-1 by 1972 following commercial whaling. However, with the projected restoration of whale populations under a RCP8.5 climate scenario, the sequestration would reach 1.7 × 105 tC yr-1 by 2100, while without climate change, recovered whale populations could sequester nearly twice as much (3.2 × 105 tC yr-1) by 2100. This highlights the persistence of whaling damages on whale populations and associated services as well as the predicted harmful impacts of climate change on whale ecosystem services.
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Affiliation(s)
- Anaëlle Durfort
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
| | - Gaël Mariani
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
| | - Vivitskaia Tulloch
- Department of Forest and Conservation Science, University of British Columbia, Vancouver, BC, Canada
| | | | | | - David Mouillot
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
- Institut Universitaire de France, 75231, Paris, France
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5
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Gallet A, Yao EK, Foucault P, Bernard C, Quiblier C, Humbert JF, Coulibaly JK, Troussellier M, Marie B, Duperron S. Fish gut-associated bacterial communities in a tropical lagoon (Aghien lagoon, Ivory Coast). Front Microbiol 2022; 13:963456. [PMID: 36246274 PMCID: PMC9556852 DOI: 10.3389/fmicb.2022.963456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/05/2022] [Indexed: 11/13/2022] Open
Abstract
Aghien lagoon (Ivory Coast) is a eutrophic freshwater lagoon that harbors high biomasses of phytoplankton. Despite Increasing interest in fish gut microbiomes diversity and functions, little data is currently available regarding wild species from tropical west African lakes. Here, gut-associated bacterial communities are investigated in four fish species that are consumed by locale populations, namely the Cichlidae Hemichromis fasciatus, Tilapia guineensis and Sarotherodon melanotheron, and the Claroteidae Chrysichthys nigrodigitatus. Species-related differences are identified, that can be attributed to host phylogeny and diet. Important variations throughout the year are observed in T. guineensis and C. nigrodigitatus. This result emphasized the importance of time-series sampling and comparison with environmental variables even in tropical regions, that are not often conducted in wild populations. Effects of environmental factors (anthropogenic or not) on the microbiota and potential outcomes for fish health and populations sustainability need to be further explored. Interestingly, fish appear as major reservoirs of bacterial diversity, suggesting that they could contribute to the overall stability and resilience of bacterial communities present in the Aghien lagoon.
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Affiliation(s)
- Alison Gallet
- UMR 7245 Molécules de Communication et Adaptation des Micro-Organismes, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Paris, France
| | - Eric Kouamé Yao
- UMR 7245 Molécules de Communication et Adaptation des Micro-Organismes, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Paris, France
- Institut Pasteur de Côte d’Ivoire, Abidjan, Côte d’Ivoire
| | - Pierre Foucault
- UMR 7245 Molécules de Communication et Adaptation des Micro-Organismes, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Paris, France
| | - Cécile Bernard
- UMR 7245 Molécules de Communication et Adaptation des Micro-Organismes, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Paris, France
| | - Catherine Quiblier
- UMR 7245 Molécules de Communication et Adaptation des Micro-Organismes, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Paris, France
- Université Paris Cité, UFR Sciences du Vivant, Paris, France
| | | | | | - Marc Troussellier
- MARBEC, Centre National de la Recherche Scientifique, Université Montpellier, IFREMER, IRD, Montpellier, France
| | - Benjamin Marie
- UMR 7245 Molécules de Communication et Adaptation des Micro-Organismes, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Paris, France
| | - Sébastien Duperron
- UMR 7245 Molécules de Communication et Adaptation des Micro-Organismes, Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Paris, France
- *Correspondence: Sébastien Duperron,
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Ahoutou MK, Yao EK, Djeha RY, Kone M, Tambosco K, Duval C, Hamlaoui S, Bernard C, Bouvy M, Marie B, Montuelle B, Troussellier M, Konan FK, Coulibaly JK, Dosso M, Humbert J, Quiblier C. Impacts of nutrient loading and fish grazing on the phytoplankton community and cyanotoxin production in a shallow tropical lake: Results from mesocosm experiments. Microbiologyopen 2022; 11:e1278. [PMID: 35478289 PMCID: PMC9059227 DOI: 10.1002/mbo3.1278] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 03/14/2022] [Indexed: 12/19/2022] Open
Abstract
Given the increasing eutrophication of water bodies in Africa due to increasing anthropogenic pressures, data are needed to better understand the responses of phytoplankton communities to these changes in tropical lakes. These ecosystems are used by local human populations for multiple purposes, including fish and drinking water production, potentially exposing these populations to health threats if, for example, an increase in toxic cyanobacterial blooms is associated with increasing eutrophication. To test the short-term response of the phytoplankton community to the addition of nutrients (phosphorus and nitrogen, alone or in combination) and Nile tilapia, we developed an in situ mesocosm experiment in a freshwater lagoon located near Abidjan (Ivory Coast). We found that phytoplankton growth (estimated by chlorophyll-a quantification) was highly stimulated when both nitrogen and phosphorus were added, while there was no clear evidence for such colimitation by these two nutrients when considering their concentrations in the lagoon. Phytoplankton growth was accompanied by significant changes in the diversity and composition of this community and did not lead to an increase in the proportions of cyanobacteria. However, the addition of fish to some mesocosms resulted in a drastic decrease in phytoplankton biomass and a dominance of chlorophytes in this community. Finally, these experiments showed that the addition of nitrogen, alone or combined with phosphorus, stimulated microcystin production by cyanobacteria. In addition, no evidence of microcystin accumulation in the fish was found. Taken together, these data allow us to discuss strategies for controlling cyanobacterial blooms in this tropical ecosystem.
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Affiliation(s)
- Mathias K. Ahoutou
- Institut Pasteur d'AbidjanAbidjanCôte d'Ivoire
- Université Jean Lorougnon Guédé UFR EnvironnementDaloaCôte d'Ivoire
| | | | | | | | | | - Charlotte Duval
- MNHN, UMR 7245 Molécules de Communication et Adaptation des Micro‐organismesParisFrance
| | - Sahima Hamlaoui
- MNHN, UMR 7245 Molécules de Communication et Adaptation des Micro‐organismesParisFrance
| | - Cécile Bernard
- MNHN, UMR 7245 Molécules de Communication et Adaptation des Micro‐organismesParisFrance
| | - Marc Bouvy
- UMR MARBEC, IRD‐Université de MontpellierMontpellierFrance
| | - Benjamin Marie
- MNHN, UMR 7245 Molécules de Communication et Adaptation des Micro‐organismesParisFrance
| | | | | | - Felix K. Konan
- Université Jean Lorougnon Guédé UFR EnvironnementDaloaCôte d'Ivoire
| | | | | | | | - Catherine Quiblier
- MNHN, UMR 7245 Molécules de Communication et Adaptation des Micro‐organismesParisFrance
- Université Paris Cité UFR Sciences du vivantParisFrance
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7
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Escalas A, Troussellier M, Melayah D, Bruto M, Nicolas S, Bernard C, Ader M, Leboulanger C, Agogué H, Hugoni M. Strong reorganization of multi-domain microbial networks associated with primary producers sedimentation from oxic to anoxic conditions in an hypersaline lake. FEMS Microbiol Ecol 2021; 97:6464137. [PMID: 34918080 DOI: 10.1093/femsec/fiab163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 12/14/2021] [Indexed: 11/14/2022] Open
Abstract
Understanding the role of microbial interactions in the functioning of natural systems is often impaired by the levels of complexity they encompass. In this study, we used the relative simplicity of an hypersaline crater lake hosting only microbial organisms (Dziani Dzaha) to provide a detailed analysis of the microbial networks including the three domains of life. We identified two main ecological zones, one euphotic and oxic zone in surface, where two phytoplanktonic organisms produce a very high biomass, and one aphotic and anoxic deeper zone, where this biomass slowly sinks and undergoes anaerobic degradation. We highlighted strong differences in the structure of microbial communities from the two zones and between the microbial consortia associated with the two primary producers. Primary producers sedimentation was associated with a major reorganization of the microbial network at several levels: global properties, modules composition, nodes and links characteristics. We evidenced the potential dependency of Woesearchaeota to the primary producers' exudates in the surface zone, and their disappearance in the deeper anoxic zone, along with the restructuration of the networks in the anoxic zone toward the decomposition of the organic matter. Altogether, we provided an in-depth analysis of microbial association network and highlighted putative changes in microbial interactions supporting the functioning of the two ecological zones in this unique ecosystem.
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Affiliation(s)
- Arthur Escalas
- MARBEC, Université de Montpellier, CNRS, IRD, IFREMER, Place Eugène Bataillon, Case 093, 34 095 Montpellier Cedex 5, France
| | - Marc Troussellier
- MARBEC, Université de Montpellier, CNRS, IRD, IFREMER, Place Eugène Bataillon, Case 093, 34 095 Montpellier Cedex 5, France
| | - Delphine Melayah
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F-69622 Villeurbanne, France
| | - Maxime Bruto
- Université de Lyon, Université Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, 43 bd du 11 novembre 1918, 69622 Villeurbanne, France
| | - Sébastien Nicolas
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F-69622 Villeurbanne, France
| | - Cécile Bernard
- UMR 7245 MCAM, Muséum National d'Histoire Naturelle - CNRS, CP 39, 75005 Paris, France
| | - Magali Ader
- Université de Paris, Institut de physique du globe de Paris, CNRS, 75005 Paris, France
| | - Christophe Leboulanger
- MARBEC, Université de Montpellier, CNRS, IRD, IFREMER, Place Eugène Bataillon, Case 093, 34 095 Montpellier Cedex 5, France
| | - Hélène Agogué
- Littoral Environnement et Sociétés (LIENSs) UMR 7266 CNRS -La Rochelle Université, 17000 La Rochelle, France
| | - Mylène Hugoni
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F-69622 Villeurbanne, France.,Institut Universitaire de France (IUF)
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8
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Koffi Ahoutou M, Yao Djeha R, Kouamé Yao E, Quiblier C, Niamen-Ebrottié J, Hamlaoui S, Tambosco K, Perrin JL, Troussellier M, Bernard C, Seguis L, Bouvy M, Pédron J, Koffi Konan F, Humbert JF, Kalpy Coulibaly J. Assessment of some key indicators of the ecological status of an African freshwater lagoon (Lagoon Aghien, Ivory Coast). PLoS One 2021; 16:e0251065. [PMID: 33956828 PMCID: PMC8101731 DOI: 10.1371/journal.pone.0251065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/19/2021] [Indexed: 11/24/2022] Open
Abstract
The supply of drinking water is a vital challenge for the people who live on the African continent, as this continent is experiencing strong demographic growth and therefore increasing water demands. To meet these needs, surface water resources are becoming increasingly mobilized because underground resources are not always available or have already been overexploited. This situation is the case in the region of Abidjan in the Ivory Coast, where the drinking water deficit is a growing problem and it is therefore necessary to mobilize new water resources to ensure the supply of drinking water. Among the potential resources, local managers have identified a freshwater lagoon, Lagoon Aghien, That is in close proximity to the city of Abidjan. With the aim of enhancing knowledge on the ecological functioning of the lagoon and contributing to the assessment of its ability to provide drinking water, several physical and chemical parameters of the water and the phytoplankton community of the lagoon were monitored for 17 months (December 2016-April 2018) at six sampling stations. Our findings show that the lagoon is eutrophic, as evidenced by the high concentrations of total phosphorus (>140 μg L-1), nitrogen (1.36 mg L-1) and average chlorophyll-a (26 to 167 μg L-1) concentrations. The phytoplankton community in the lagoon is dominated by genera typical of eutrophic environments including mixotrophic genera such as Peridinium and by cyanobacteria such as Cylindrospermopsis/Raphidiopsis, Microcystis and Dolichospermum that can potentially produce cyanotoxins. The two rainfall peaks that occur in June and October appeared to be major events in terms of nutrient flows entering the lagoon, and the dynamics of these flows are complex. Significant differences were also found in the nutrient concentrations and to a lesser extent in the phytoplankton communities among the different stations, especially during the rainfall peaks. Overall, these results reveal that the quality of the lagoon’s water is already severely degraded, and this degradation could increase in future years due to increasing urbanization in the watershed. These results therefore raise questions about the potential use of the lagoon as a source of drinking water if measures are not taken very quickly to protect this lagoon from increasing eutrophication and other pollution sources.
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Affiliation(s)
- Mathias Koffi Ahoutou
- Institut Pasteur d’Abidjan, Abidjan, Côte d’Ivoire
- Université Jean Lorougnon Guédé, Daloa, Côte d’Ivoire
| | | | | | - Catherine Quiblier
- MNHN, UMR 7245 Molécules de Communication et Adaptation des Micro-organismes, Paris, France
- Université de Paris, Paris, France
| | - Julie Niamen-Ebrottié
- Laboratory of Environment and Aquatic Biology, Nangui Abrogoua University, Abidjan, Côte d’Ivoire
| | - Sahima Hamlaoui
- MNHN, UMR 7245 Molécules de Communication et Adaptation des Micro-organismes, Paris, France
| | | | - Jean-Louis Perrin
- HydroSciences Montpellier, IRD, Université de Montpellier, CNRS, Montpellier, France
| | | | - Cécile Bernard
- MNHN, UMR 7245 Molécules de Communication et Adaptation des Micro-organismes, Paris, France
| | - Luc Seguis
- HydroSciences Montpellier, IRD, Université de Montpellier, CNRS, Montpellier, France
| | - Marc Bouvy
- UMR MARBEC, IRD-Université de Montpellier, Montpellier, France
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9
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Mariani G, Cheung WWL, Lyet A, Sala E, Mayorga J, Velez L, Gaines SD, Dejean T, Troussellier M, Mouillot D. Let more big fish sink: Fisheries prevent blue carbon sequestration-half in unprofitable areas. Sci Adv 2020; 6:6/44/eabb4848. [PMID: 33115738 PMCID: PMC7608781 DOI: 10.1126/sciadv.abb4848] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 09/15/2020] [Indexed: 05/13/2023]
Abstract
Contrary to most terrestrial organisms, which release their carbon into the atmosphere after death, carcasses of large marine fish sink and sequester carbon in the deep ocean. Yet, fisheries have extracted a massive amount of this "blue carbon," contributing to additional atmospheric CO2 emissions. Here, we used historical catches and fuel consumption to show that ocean fisheries have released a minimum of 0.73 billion metric tons of CO2 (GtCO2) in the atmosphere since 1950. Globally, 43.5% of the blue carbon extracted by fisheries in the high seas comes from areas that would be economically unprofitable without subsidies. Limiting blue carbon extraction by fisheries, particularly on unprofitable areas, would reduce CO2 emissions by burning less fuel and reactivating a natural carbon pump through the rebuilding of fish stocks and the increase of carcasses deadfall.
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Affiliation(s)
- Gaël Mariani
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France.
| | - William W L Cheung
- Changing Ocean Research Unit, Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, BC, Canada
| | - Arnaud Lyet
- World Wildlife Fund, Washington, DC 20037, USA
| | - Enric Sala
- National Geographic Society, Washington, DC 20036, USA
| | - Juan Mayorga
- National Geographic Society, Washington, DC 20036, USA
- University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Laure Velez
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
| | - Steven D Gaines
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106, USA
| | - Tony Dejean
- SPYGEN, 17 rue du Lac Saint-André, Savoie Technolac, Le Bourget du Lac, France
| | | | - David Mouillot
- MARBEC, Univ Montpellier, CNRS, IFREMER, IRD, Montpellier, France
- Institut Universitaire de France, Paris, France
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10
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Olokotum M, Mitroi V, Troussellier M, Semyalo R, Bernard C, Montuelle B, Okello W, Quiblier C, Humbert JF. A review of the socioecological causes and consequences of cyanobacterial blooms in Lake Victoria. Harmful Algae 2020; 96:101829. [PMID: 32560832 DOI: 10.1016/j.hal.2020.101829] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 05/01/2020] [Accepted: 05/07/2020] [Indexed: 06/11/2023]
Abstract
Africa is experiencing high annual population growth in its major river basins. This growth has resulted in significant land use change and pollution pressures on the freshwater ecosystems. Among them, the Lake Victoria basin, with more than 42 million people, is a unique and vital resource that provides food and drinking water in East Africa. However, Lake Victoria (LV) has experienced a progressive eutrophication and substantial changes in the fish community leading to recurrent proliferation of water hyacinth and cyanobacteria. Based on an extensive literature review, we show that cyanobacterial biomasses and microcystin concentrations are higher in the bays and gulfs (B&Gs) than in the open lake (OL), with Microcystis and Dolichospermum as the dominant genera. These differences between the B&Gs and the OL are due to differences in their hydrological conditions and in the origins, type and quantities of nutrients. Using data from the literature, we describe the multiple ways in which the human population growth in the LV watershed is connected to the increasing occurrence of cyanobacterial blooms in the OL and B&Gs. We also described the consequences of cyanobacterial blooms on food resources and fishing and on direct water use and water supply of local populations, with their potential consequences on the human health. Finally, we discuss the actions that have been taken for the protection of LV. Although many projects have been implemented in the past years in order to improve the management of waste waters or to reduce deforestation and erosion, the huge challenge of the reduction of cyanobacterial blooms in LV by the control of eutrophication seems far from being achieved.
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Affiliation(s)
- Mark Olokotum
- Department of Zoology, Entomology and Fisheries Sciences, Makerere University, Kampala, Uganda; National Fisheries Resources Research Institute (NaFIRRI), Jinja, Uganda
| | - Veronica Mitroi
- INRAE-Institute of Ecology and Environmental Sciences of Paris (iEES), Sorbonne University, Paris, France
| | - Marc Troussellier
- UMR MARBEC, CNRS-University of Montpellier-IRD-IFREMER, Place Eugène Bataillon, Montpellier, France
| | - Ronald Semyalo
- Department of Zoology, Entomology and Fisheries Sciences, Makerere University, Kampala, Uganda
| | - Cécile Bernard
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), CNRS-MNHN, Muséum National d'Histoire Naturelle, Paris, France
| | | | - William Okello
- National Fisheries Resources Research Institute (NaFIRRI), Jinja, Uganda
| | - Catherine Quiblier
- UMR 7245 Molécules de Communication et Adaptations des Microorganismes (MCAM), CNRS-MNHN, Muséum National d'Histoire Naturelle, Paris, France; University of Paris, France
| | - Jean-François Humbert
- INRAE-Institute of Ecology and Environmental Sciences of Paris (iEES), Sorbonne University, Paris, France
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11
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Escalas A, Catherine A, Maloufi S, Cellamare M, Hamlaoui S, Yéprémian C, Louvard C, Troussellier M, Bernard C. Drivers and ecological consequences of dominance in periurban phytoplankton communities using networks approaches. Water Res 2019; 163:114893. [PMID: 31351356 DOI: 10.1016/j.watres.2019.114893] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/18/2019] [Accepted: 07/19/2019] [Indexed: 06/10/2023]
Abstract
Evaluating the causes and consequences of dominance by a limited number of taxa in phytoplankton communities is of huge importance in the current context of increasing anthropogenic pressures on natural ecosystems. This is of particular concern in densely populated urban areas where usages and impacts of human populations on water ecosystems are strongly interconnected. Microbial biodiversity is commonly used as a bioindicator of environmental quality and ecosystem functioning, but there are few studies at the regional scale that integrate the drivers of dominance in phytoplankton communities and their consequences on the structure and functioning of these communities. Here, we studied the causes and consequences of phytoplankton dominance in 50 environmentally contrasted waterbodies, sampled over four summer campaigns in the highly-populated Île-de-France region (IDF). Phytoplankton dominance was observed in 32-52% of the communities and most cases were attributed to Chlorophyta (35.5-40.6% of cases) and Cyanobacteria (30.3-36.5%). The best predictors of dominance were identified using multinomial logistic regression and included waterbody features (surface, depth and connection to the hydrological network) and water column characteristics (total N, TN:TP ratio, water temperature and stratification). The consequences of dominance were dependent on the identity of the dominant organisms and included modifications of biological attributes (richness, cohesion) and functioning (biomass, RUE) of phytoplankton communities. We constructed co-occurrence networks using high resolution phytoplankton biomass and demonstrated that networks under dominance by Chlorophyta and Cyanobacteria exhibited significantly different structure compared with networks without dominance. Furthermore, dominance by Cyanobacteria was associated with more profound network modifications (e.g. cohesion, size, density, efficiency and proportion of negative links), suggesting a stronger disruption of the structure and functioning of phytoplankton communities in the conditions in which this group dominates. Finally, we provide a synthesis on the relationships between environmental drivers, dominance status, community attributes and network structure.
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Affiliation(s)
- Arthur Escalas
- UMR 7245 MCAM, CNRS-MNHN, Muséum National D'Histoire Naturelle, 12 Rue Buffon, CP 39, 75231, Paris Cedex 05, France; UMR 9190 MARBEC, CNRS-Université de Montpellier-IRD-IFREMER, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France.
| | - Arnaud Catherine
- UMR 7245 MCAM, CNRS-MNHN, Muséum National D'Histoire Naturelle, 12 Rue Buffon, CP 39, 75231, Paris Cedex 05, France
| | - Selma Maloufi
- UMR 7245 MCAM, CNRS-MNHN, Muséum National D'Histoire Naturelle, 12 Rue Buffon, CP 39, 75231, Paris Cedex 05, France
| | - Maria Cellamare
- UMR 7245 MCAM, CNRS-MNHN, Muséum National D'Histoire Naturelle, 12 Rue Buffon, CP 39, 75231, Paris Cedex 05, France; Phyto-Quality, 15 Rue Pétrarque, 75116, Paris, France
| | - Sahima Hamlaoui
- UMR 7245 MCAM, CNRS-MNHN, Muséum National D'Histoire Naturelle, 12 Rue Buffon, CP 39, 75231, Paris Cedex 05, France
| | - Claude Yéprémian
- UMR 7245 MCAM, CNRS-MNHN, Muséum National D'Histoire Naturelle, 12 Rue Buffon, CP 39, 75231, Paris Cedex 05, France
| | - Clarisse Louvard
- UMR 7245 MCAM, CNRS-MNHN, Muséum National D'Histoire Naturelle, 12 Rue Buffon, CP 39, 75231, Paris Cedex 05, France
| | - Marc Troussellier
- UMR 9190 MARBEC, CNRS-Université de Montpellier-IRD-IFREMER, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France
| | - Cécile Bernard
- UMR 7245 MCAM, CNRS-MNHN, Muséum National D'Histoire Naturelle, 12 Rue Buffon, CP 39, 75231, Paris Cedex 05, France.
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12
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Bernard C, Escalas A, Villeriot N, Agogué H, Hugoni M, Duval C, Carré C, Got P, Sarazin G, Jézéquel D, Leboulanger C, Grossi V, Ader M, Troussellier M. Very Low Phytoplankton Diversity in a Tropical Saline-Alkaline Lake, with Co-dominance of Arthrospira fusiformis (Cyanobacteria) and Picocystis salinarum (Chlorophyta). Microb Ecol 2019; 78:603-617. [PMID: 30729265 PMCID: PMC6744573 DOI: 10.1007/s00248-019-01332-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 01/16/2019] [Indexed: 05/03/2023]
Abstract
Lake Dziani Dzaha (Mayotte Island, Indian Ocean) is a tropical thalassohaline lake which geochemical and biological conditions make it a unique aquatic ecosystem considered as a modern analogue of Precambrian environments. In the present study, we focused on the diversity of phytoplanktonic communities, which produce very high and stable biomass (mean2014-2015 = 652 ± 179 μg chlorophyll a L-1). As predicted by classical community ecology paradigms, and as observed in similar environments, a single species is expected to dominate the phytoplanktonic communities. To test this hypothesis, we sampled water column in the deepest part of the lake (18 m) during rainy and dry seasons for two consecutive years. Phytoplanktonic communities were characterized using a combination of metagenomic, microscopy-based and flow cytometry approaches, and we used statistical modeling to identify the environmental factors determining the abundance of dominant organisms. As hypothesized, the overall diversity of the phytoplanktonic communities was very low (15 OTUs), but we observed a co-dominance of two, and not only one, OTUs, viz., Arthrospira fusiformis (Cyanobacteria) and Picocystis salinarum (Chlorophyta). We observed a decrease in the abundance of these co-dominant taxa along the depth profile and identified the adverse environmental factors driving this decline. The functional traits measured on isolated strains of these two taxa (i.e., size, pigment composition, and concentration) are then compared and discussed to explain their capacity to cope with the extreme environmental conditions encountered in the aphotic, anoxic, and sulfidic layers of the water column of Lake Dziani Dzaha.
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Affiliation(s)
- C Bernard
- UMR 7245 MCAM, Muséum National d'Histoire Naturelle - CNRS, 57 Rue Cuvier, CP 39, 75231, Paris Cedex 05, France.
| | - A Escalas
- UMR 7245 MCAM, Muséum National d'Histoire Naturelle - CNRS, 57 Rue Cuvier, CP 39, 75231, Paris Cedex 05, France
| | - N Villeriot
- UMR 7245 MCAM, Muséum National d'Histoire Naturelle - CNRS, 57 Rue Cuvier, CP 39, 75231, Paris Cedex 05, France
- UMR 9190 MARBEC, CNRS - Université de Montpellier - IRD - IFREMER, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France
| | - H Agogué
- UMR 7266 LIENSs, Université de La Rochelle - CNRS, 2 rue Olympe de Gouges, 17000, La Rochelle, France
| | - M Hugoni
- UMR 5557 Ecologie Microbienne, Université Lyon 1 - CNRS - INRA, 69220, Villeurbanne Cedex, France
| | - C Duval
- UMR 7245 MCAM, Muséum National d'Histoire Naturelle - CNRS, 57 Rue Cuvier, CP 39, 75231, Paris Cedex 05, France
| | - C Carré
- UMR 9190 MARBEC, CNRS - Université de Montpellier - IRD - IFREMER, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France
| | - P Got
- UMR 9190 MARBEC, CNRS - Université de Montpellier - IRD - IFREMER, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France
| | - G Sarazin
- UMR 7154 Institut de Physique du Globe de Paris - Sorbonne Paris Cité, Université Paris Diderot, 1 rue de Jussieu, 75005, Paris, France
| | - D Jézéquel
- UMR 7154 Institut de Physique du Globe de Paris - Sorbonne Paris Cité, Université Paris Diderot, 1 rue de Jussieu, 75005, Paris, France
| | - C Leboulanger
- UMR 9190 MARBEC, CNRS - Université de Montpellier - IRD - IFREMER, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France
| | - V Grossi
- Laboratoire de Géologie de Lyon, Université de Lyon - CNRS - UCBL - ENSL, 69220 Villeurbanne, France
| | - M Ader
- UMR 7154 Institut de Physique du Globe de Paris - Sorbonne Paris Cité, Université Paris Diderot, 1 rue de Jussieu, 75005, Paris, France
| | - M Troussellier
- UMR 9190 MARBEC, CNRS - Université de Montpellier - IRD - IFREMER, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France
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13
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Hugoni M, Escalas A, Bernard C, Nicolas S, Jézéquel D, Vazzoler F, Sarazin G, Leboulanger C, Bouvy M, Got P, Ader M, Troussellier M, Agogué H. Spatiotemporal variations in microbial diversity across the three domains of life in a tropical thalassohaline lake (Dziani Dzaha, Mayotte Island). Mol Ecol 2018; 27:4775-4786. [DOI: 10.1111/mec.14901] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 11/28/2022]
Affiliation(s)
- Mylène Hugoni
- Université Lyon 1; CNRS; UMR5557; Ecologie Microbienne; INRA; UMR1418; Villeurbanne France
| | - Arthur Escalas
- UMR 7245 MCAM; Muséum National d'Histoire Naturelle - CNRS; CP 39; Paris France
| | - Cécile Bernard
- UMR 7245 MCAM; Muséum National d'Histoire Naturelle - CNRS; CP 39; Paris France
| | - Sébastien Nicolas
- Université Lyon 1; CNRS; UMR5557; Ecologie Microbienne; INRA; UMR1418; Villeurbanne France
| | - Didier Jézéquel
- Institut de Physique du Globe de Paris - Sorbonne Paris Cité; Univ. Paris Diderot; UMR 7154 CNRS; Paris France
| | - Fanny Vazzoler
- UMR 7266 LIENSs CNRS; Univ. La Rochelle; La Rochelle France
| | - Gerard Sarazin
- Institut de Physique du Globe de Paris - Sorbonne Paris Cité; Univ. Paris Diderot; UMR 7154 CNRS; Paris France
| | | | - Marc Bouvy
- UMR 9190; MARBEC; CNRS; Univ. Montpellier; IRD; Ifremer; Montpellier France
| | - Patrice Got
- UMR 9190; MARBEC; CNRS; Univ. Montpellier; IRD; Ifremer; Montpellier France
| | - Magali Ader
- Institut de Physique du Globe de Paris - Sorbonne Paris Cité; Univ. Paris Diderot; UMR 7154 CNRS; Paris France
| | - Marc Troussellier
- UMR 9190; MARBEC; CNRS; Univ. Montpellier; IRD; Ifremer; Montpellier France
| | - Hélène Agogué
- UMR 7266 LIENSs CNRS; Univ. La Rochelle; La Rochelle France
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14
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Duval C, Thomazeau S, Drelin Y, Yéprémian C, Bouvy M, Couloux A, Troussellier M, Rousseau F, Bernard C. Phylogeny and salt-tolerance of freshwater Nostocales strains: Contribution to their systematics and evolution. Harmful Algae 2018; 73:58-71. [PMID: 29602507 DOI: 10.1016/j.hal.2018.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 01/06/2018] [Accepted: 01/21/2018] [Indexed: 06/08/2023]
Abstract
Phylogenetic relationships among heterocytous genera (the Nostocales order) have been profoundly modified since the use of polyphasic approaches that include molecular data. There is nonetheless still ample scope for improving phylogenetic delineations of genera with broad ecological distributions, particularly by integrating specimens from specific or up-to-now poorly sampled habitats. In this context, we studied 36 new isolates belonging to Chrysosporum, Dolichospermum, Anabaena, Anabaenopsis, and Cylindrospermopsis from freshwater ecosystems of Burkina-Faso, Senegal, and Mayotte Island. Studying strains from these habitats is of particular interest as we suspected different range of salt variations during underwent periods of drought in small ponds and lakes. Such salt variation may cause different adaptation to salinity. We then undertook a polyphasic approach, combining molecular phylogenies, morphological analyses, and physiological measurements of tolerance to salinity. Molecular phylogenies of 117 Nostocales sequences showed that the 36 studied strains were distributed in seven lineages: Dolichospermum, Chrysosporum, Cylindrospermopsis/Raphidiopsis, Anabaenopsis, Anabaena sphaerica var tenuis/Sphaerospermopsis, and two independent Anabaena sphaerica lineages. Physiological data were congruent with molecular results supporting the separation into seven lineages. In an evolutionary context, salinity tolerance can be used as an integrative marker to reinforce the delineation of some cyanobacterial lineages. The history of this physiological trait contributes to a better understanding of processes leading to the divergence of cyanobacteria. In this study, most of the cyanobacterial strains isolated from freshwater environments were salt-tolerant, thus suggesting this trait constituted an ancestral trait of the heterocytous cyanobacteria and that it was probably lost two times secondarily and independently in the ancestor of Dolichospermum and of Cylindrospermopsis.
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Affiliation(s)
- Charlotte Duval
- UMR 7245 MCAM CNRS-MNHN, Muséum National d'Histoire Naturelle, CNRS, CP 39, 12 rue Buffon, F-75231 Paris Cedex 05, France
| | - Solène Thomazeau
- UMR 7245 MCAM CNRS-MNHN, Muséum National d'Histoire Naturelle, CNRS, CP 39, 12 rue Buffon, F-75231 Paris Cedex 05, France
| | - Yannick Drelin
- UMR 7245 MCAM CNRS-MNHN, Muséum National d'Histoire Naturelle, CNRS, CP 39, 12 rue Buffon, F-75231 Paris Cedex 05, France
| | - Claude Yéprémian
- UMR 7245 MCAM CNRS-MNHN, Muséum National d'Histoire Naturelle, CNRS, CP 39, 12 rue Buffon, F-75231 Paris Cedex 05, France
| | - Marc Bouvy
- UMR 9190 MARBEC, Université de Montpellier, CNRS, IRD Ifremer, CP 093, Place Eugène Bataillon, F-34095 Montpellier Cedex 5, France
| | - Arnaud Couloux
- Genoscope, Centre national de séquençage, 2, rue Gaston Crémieux, CP 5706, F-91057 Évry Cedex, France
| | - Marc Troussellier
- UMR 9190 MARBEC, Université de Montpellier, CNRS, IRD Ifremer, CP 093, Place Eugène Bataillon, F-34095 Montpellier Cedex 5, France
| | - Florence Rousseau
- UMR 7138ISYEB, Muséum National d'Histoire Naturelle, UPMC, CNRS, EPHE, CP39, 12 rue Buffon, F-75231 Paris Cedex 05, France
| | - Cécile Bernard
- UMR 7245 MCAM CNRS-MNHN, Muséum National d'Histoire Naturelle, CNRS, CP 39, 12 rue Buffon, F-75231 Paris Cedex 05, France.
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15
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Escalas A, Troussellier M, Yuan T, Bouvier T, Bouvier C, Mouchet MA, Flores Hernandez D, Ramos Miranda J, Zhou J, Mouillot D. Functional diversity and redundancy across fish gut, sediment and water bacterial communities. Environ Microbiol 2017; 19:3268-3282. [PMID: 28618142 DOI: 10.1111/1462-2920.13822] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 06/07/2017] [Indexed: 11/26/2022]
Abstract
This article explores the functional diversity and redundancy in a bacterial metacommunity constituted of three habitats (sediment, water column and fish gut) in a coastal lagoon under anthropogenic pressure. Comprehensive functional gene arrays covering a wide range of ecological processes and stress resistance genes to estimate the functional potential of bacterial communities were used. Then, diversity partitioning was used to characterize functional diversity and redundancy within (α), between (β) and across (γ) habitats. It was showed that all local communities exhibit a highly diversified potential for the realization of key ecological processes and resistance to various environmental conditions, supporting the growing evidence that macro-organisms microbiomes harbour a high functional potential and are integral components of functional gene dynamics in aquatic bacterial metacommunities. Several levels of functional redundancy at different scales of the bacterial metacommunity were observed (within local communities, within habitats and at the metacommunity level). The results suggested a high potential for the realization of spatial ecological insurance within this ecosystem, that is, the functional compensation among microorganisms for the realization and maintenance of key ecological processes, within and across habitats. Finally, the role of macro-organisms as dispersal vectors of microbes and their potential influence on marine metacommunity dynamics were discussed.
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Affiliation(s)
- Arthur Escalas
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Marc Troussellier
- UMR 9190 MARBEC, IRD-CNRS-UM-IFREMER, Université Montpellier, 34095 Montpellier Cedex, France
| | - Tong Yuan
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Thierry Bouvier
- UMR 9190 MARBEC, IRD-CNRS-UM-IFREMER, Université Montpellier, 34095 Montpellier Cedex, France
| | - Corinne Bouvier
- UMR 9190 MARBEC, IRD-CNRS-UM-IFREMER, Université Montpellier, 34095 Montpellier Cedex, France
| | - Maud A Mouchet
- UMR 7204 CESCO, Muséum d'Histoire Naturelle, 55 rue Buffon, Paris, 75005, France
| | - Domingo Flores Hernandez
- Centro de Ecología, Pesquerias y Oceanographia de Golfo de México, Universidad Autonoma de Campeche, Campeche, Mexico
| | - Julia Ramos Miranda
- Centro de Ecología, Pesquerias y Oceanographia de Golfo de México, Universidad Autonoma de Campeche, Campeche, Mexico
| | - Jizhong Zhou
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, 73019, USA.,Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - David Mouillot
- UMR 9190 MARBEC, IRD-CNRS-UM-IFREMER, Université Montpellier, 34095 Montpellier Cedex, France.,Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia
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16
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Troussellier M, Escalas A, Bouvier T, Mouillot D. Sustaining Rare Marine Microorganisms: Macroorganisms As Repositories and Dispersal Agents of Microbial Diversity. Front Microbiol 2017; 8:947. [PMID: 28611749 PMCID: PMC5447324 DOI: 10.3389/fmicb.2017.00947] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 05/11/2017] [Indexed: 12/14/2022] Open
Abstract
Recent analyses revealed that most of the biodiversity observed in marine microbial communities is represented by organisms with low abundance but, nonetheless essential for ecosystem dynamics and processes across both temporal and spatial scales. Surprisingly, few studies have considered the effect of macroorganism–microbe interactions on the ecology and distribution dynamics of rare microbial taxa. In this review, we synthesize several lines of evidence that these relationships cannot be neglected any longer. First, we provide empirical support that the microbiota of macroorganisms represents a significant part of marine bacterial biodiversity and that host-microbe interactions benefit to certain microbial populations which are part of the rare biosphere (i.e., opportunistic copiotrophic organisms). Second, we reveal the major role that macroorganisms may have on the dispersal and the geographic distribution of microbes. Third, we introduce an innovative and integrated view of the interactions between microbes and macroorganisms, namely sustaining the rares, which suggests that macroorganisms favor the maintenance of marine microbial diversity and are involved in the regulation of its richness and dynamics. Finally, we show how this hypothesis complements existing theories in microbial ecology and offers new perspectives about the importance of macroorganisms for the microbial biosphere, particularly the rare members.
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Affiliation(s)
- Marc Troussellier
- MARBEC, UMR IRD-CNRS-UM-IFREMER 9190, Université MontpellierMontpellier, France
| | - Arthur Escalas
- Institute for Environmental Genomics, Department of Microbiology and Plant Biology, University of Oklahoma, NormanOK, United States
| | - Thierry Bouvier
- MARBEC, UMR IRD-CNRS-UM-IFREMER 9190, Université MontpellierMontpellier, France
| | - David Mouillot
- MARBEC, UMR IRD-CNRS-UM-IFREMER 9190, Université MontpellierMontpellier, France.,Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, TownsvilleQLD, Australia
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Catherine A, Selma M, Mouillot D, Troussellier M, Bernard C. Patterns and multi-scale drivers of phytoplankton species richness in temperate peri-urban lakes. Sci Total Environ 2016; 559:74-83. [PMID: 27054495 DOI: 10.1016/j.scitotenv.2016.03.179] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 01/07/2016] [Accepted: 03/24/2016] [Indexed: 05/20/2023]
Abstract
Local species richness (SR) is a key characteristic affecting ecosystem functioning. Yet, the mechanisms regulating phytoplankton diversity in freshwater ecosystems are not fully understood, especially in peri-urban environments where anthropogenic pressures strongly impact the quality of aquatic ecosystems. To address this issue, we sampled the phytoplankton communities of 50 lakes in the Paris area (France) characterized by a large gradient of physico-chemical and catchment-scale characteristics. We used large phytoplankton datasets to describe phytoplankton diversity patterns and applied a machine-learning algorithm to test the degree to which species richness patterns are potentially controlled by environmental factors. Selected environmental factors were studied at two scales: the lake-scale (e.g. nutrients concentrations, water temperature, lake depth) and the catchment-scale (e.g. catchment, landscape and climate variables). Then, we used a variance partitioning approach to evaluate the interaction between lake-scale and catchment-scale variables in explaining local species richness. Finally, we analysed the residuals of predictive models to identify potential vectors of improvement of phytoplankton species richness predictive models. Lake-scale and catchment-scale drivers provided similar predictive accuracy of local species richness (R(2)=0.458 and 0.424, respectively). Both models suggested that seasonal temperature variations and nutrient supply strongly modulate local species richness. Integrating lake- and catchment-scale predictors in a single predictive model did not provide increased predictive accuracy; therefore suggesting that the catchment-scale model probably explains observed species richness variations through the impact of catchment-scale variables on in-lake water quality characteristics. Models based on catchment characteristics, which include simple and easy to obtain variables, provide a meaningful way of predicting phytoplankton species richness in temperate lakes. This approach may prove useful and cost-effective for the management and conservation of aquatic ecosystems.
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Affiliation(s)
- Arnaud Catherine
- UMR7245 MCAM MNHN-CNRS, Muséum National d'Histoire Naturelle, CC 39, 12 rue Buffon, F-75231 Paris, Cedex 05, France.
| | - Maloufi Selma
- UMR7245 MCAM MNHN-CNRS, Muséum National d'Histoire Naturelle, CC 39, 12 rue Buffon, F-75231 Paris, Cedex 05, France.
| | - David Mouillot
- UMR 9190 MARBEC UM2-CNRS-IRD-UM1-IFREMER, CC 93, Place Eugène Bataillon, Université de Montpellier 2, F-34095 Montpellier, France.
| | - Marc Troussellier
- UMR 9190 MARBEC UM2-CNRS-IRD-UM1-IFREMER, CC 93, Place Eugène Bataillon, Université de Montpellier 2, F-34095 Montpellier, France.
| | - Cécile Bernard
- UMR7245 MCAM MNHN-CNRS, Muséum National d'Histoire Naturelle, CC 39, 12 rue Buffon, F-75231 Paris, Cedex 05, France.
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Albouy C, Lasram FBR, Velez L, Guilhaumon F, Meynard CN, Boyer S, Benestan L, Mouquet N, Douzery E, Aznar R, Troussellier M, Somot S, Leprieur F, Le Loc'h F, Mouillot D. FishMed: traits, phylogeny, current and projected species distribution of Mediterranean fishes, and environmental data. Ecology 2015. [DOI: 10.1890/14-2279.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Guilhaumon F, Albouy C, Claudet J, Velez L, Ben Rais Lasram F, Tomasini JA, Douzery EJP, Meynard CN, Mouquet N, Troussellier M, Araújo MB, Mouillot D. Representing taxonomic, phylogenetic and functional diversity: new challenges for Mediterranean marine-protected areas. DIVERS DISTRIB 2014. [DOI: 10.1111/ddi.12280] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- François Guilhaumon
- ‘Rui Nabeiro’ Biodiversity Chair; CIBIO; University of Évora; Casa Cordovil, 2° Andar Rua Dr. Joaquim Henrique da Fonseca 7000-890 c Portugal
- IRD; UMR 5119; IRD-CNRS-IFREMER-UM2-UM1 ECOSYM; Université Montpellier 2; cc 093, Place E. Bataillon 34095 Montpellier Cedex 05 France
| | - Camille Albouy
- IRD; UMR 5119; IRD-CNRS-IFREMER-UM2-UM1 ECOSYM; Université Montpellier 2; cc 093, Place E. Bataillon 34095 Montpellier Cedex 05 France
- Département de Biologie, Chimie et Géographie; Université du Québec à Rimouski; 300 Allée des Ursulines Rimouski QC Canada G5L 3A1
| | - Joachim Claudet
- National Center for Scientific Research; USR 3278; CNRS-EPHE CRIOBE; University of Perpignan; 66860 Perpignan Cedex France
- Laboratoire d'Excellence ‘CORAIL’; Tunis Tunisia
| | - Laure Velez
- IRD; UMR 5119; IRD-CNRS-IFREMER-UM2-UM1 ECOSYM; Université Montpellier 2; cc 093, Place E. Bataillon 34095 Montpellier Cedex 05 France
| | - Frida Ben Rais Lasram
- Laboratoire Écosystèmes et Ressources Aquatiques UR03AGRO1; Institut National Agronomique de Tunisie; 43 Avenue Charles Nicolle 1082 Tunis Tunisia
| | - Jean-Antoine Tomasini
- IRD; UMR 5119; IRD-CNRS-IFREMER-UM2-UM1 ECOSYM; Université Montpellier 2; cc 093, Place E. Bataillon 34095 Montpellier Cedex 05 France
| | - Emmanuel J. P. Douzery
- Institut des Sciences de l'Evolution; UMR 5554; CNRS; UM2; cc 065, Place E. Bataillon 34095 Montpellier Cedex 05 France
| | - Christine N. Meynard
- Institut des Sciences de l'Evolution; UMR 5554; CNRS; UM2; cc 065, Place E. Bataillon 34095 Montpellier Cedex 05 France
- INRA; UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro); Campus International de Baillarguet; CS 30016 FR-34988 Montferrier-sur-Lez cedex France
- Virginia Institute of Marine Science; College of William & Mary; PO Box 1346 Gloucester Point VA 23062 USA
| | - Nicolas Mouquet
- Institut des Sciences de l'Evolution; UMR 5554; CNRS; UM2; cc 065, Place E. Bataillon 34095 Montpellier Cedex 05 France
| | - Marc Troussellier
- IRD; UMR 5119; IRD-CNRS-IFREMER-UM2-UM1 ECOSYM; Université Montpellier 2; cc 093, Place E. Bataillon 34095 Montpellier Cedex 05 France
| | - Miguel B. Araújo
- ‘Rui Nabeiro’ Biodiversity Chair; CIBIO; University of Évora; Casa Cordovil, 2° Andar Rua Dr. Joaquim Henrique da Fonseca 7000-890 c Portugal
- Departamento de Biogeografía y Cambio Global; Museo Nacional de Ciencias Naturales; CSIC; C/José Gutiérrez Abascal, 2 28006 Madrid Spain
- Center for Macroecology, Evolution and Climate; University of Copenhagen; Universitetsparken 15 2100 Copenhagen Denmark
- Division of Ecology and Evolution; Imperial College London; Silwood Park Buckhurst Road Ascot Berkshire SL5 7PY UK
| | - David Mouillot
- IRD; UMR 5119; IRD-CNRS-IFREMER-UM2-UM1 ECOSYM; Université Montpellier 2; cc 093, Place E. Bataillon 34095 Montpellier Cedex 05 France
- ARC Centre of Excellence for Coral Reef Studies; James Cook University; Townsville Qld 4811 Australia
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Catherine A, Mouillot D, Maloufi S, Troussellier M, Bernard C. Projecting the impact of regional land-use change and water management policies on lake water quality: an application to periurban lakes and reservoirs. PLoS One 2013; 8:e72227. [PMID: 23991066 PMCID: PMC3753357 DOI: 10.1371/journal.pone.0072227] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 07/07/2013] [Indexed: 11/19/2022] Open
Abstract
As the human population grows, the demand for living space and supplies of resources also increases, which may induce rapid change in land-use/land-cover (LULC) and associated pressures exerted on aquatic habitats. We propose a new approach to forecast the impact of regional land cover change and water management policies (i.e., targets in nutrient loads reduction) on lake and reservoir water eutrophication status using a model that requires minimal parameterisation compared with alternative methods. This approach was applied to a set of 48 periurban lakes located in the Ile de France region (IDF, France) to simulate catchment-scale management scenarios. Model outputs were subsequently compared to governmental agencies' 2030 forecasts. Our model indicated that the efforts made to reduce pressure in the catchment of seepage lakes might be expected to be proportional to the gain that might be obtained, whereas drainage lakes will display little improvement until a critical level of pressure reduction is reached. The model also indicated that remediation measures, as currently planned by governmental agencies, might only have a marginal impact on improving the eutrophication status of lakes and reservoirs within the IDF region. Despite the commitment to appropriately managing the water resources in many countries, prospective tools to evaluate the potential impacts of global change on freshwater ecosystems integrity at medium to large spatial scales are lacking. This study proposes a new approach to investigate the impact of region-scale human-driven changes on lake and reservoir ecological status and could be implemented elsewhere with limited parameterisation. Issues are discussed that relate to model uncertainty and to its relevance as a tool applied to decision-making.
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Affiliation(s)
- Arnaud Catherine
- Laboratoire Molécules de communication et adaptation des micro-organismes, Muséum national d'Histoire naturelle, Paris, Ile-de-France, France.
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Escalas A, Bouvier T, Mouchet MA, Leprieur F, Bouvier C, Troussellier M, Mouillot D. A unifying quantitative framework for exploring the multiple facets of microbial biodiversity across diverse scales. Environ Microbiol 2013; 15:2642-57. [PMID: 23731353 DOI: 10.1111/1462-2920.12156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 05/05/2013] [Accepted: 05/07/2013] [Indexed: 01/26/2023]
Abstract
Recent developments of molecular tools have revolutionized our knowledge of microbial biodiversity by allowing detailed exploration of its different facets and generating unprecedented amount of data. One key issue with such large datasets is the development of diversity measures that cope with different data outputs and allow comparison of biodiversity across different scales. Diversity has indeed three components: local (α), regional (γ) and the overall difference between local communities (β). Current measures of microbial diversity, derived from several approaches, provide complementary but different views. They only capture the β component of diversity, compare communities in a pairwise way, consider all species as equivalent or lack a mathematically explicit relationship among the α, β and γ components. We propose a unified quantitative framework based on the Rao quadratic entropy, to obtain an additive decomposition of diversity (γ = α + β), so the three components can be compared, and that integrate the relationship (phylogenetic or functional) among Microbial Diversity Units that compose a microbial community. We show how this framework is adapted to all types of molecular data, and we highlight crucial issues in microbial ecology that would benefit from this framework and propose ready-to-use R-functions to easily set up our approach.
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Affiliation(s)
- Arthur Escalas
- UMR 5119 CNRS-UM2-UM1-IRD-Ifremer Ecologie des systèmes marins côtiers, Université Montpellier 2 cc 093, 34 095, Montpellier Cedex 5, France
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22
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Ledreux A, Sérandour AL, Morin B, Derick S, Lanceleur R, Hamlaoui S, Furger C, Biré R, Krys S, Fessard V, Troussellier M, Bernard C. Collaborative study for the detection of toxic compounds in shellfish extracts using cell-based assays. Part II: application to shellfish extracts spiked with lipophilic marine toxins. Anal Bioanal Chem 2012; 403:1995-2007. [DOI: 10.1007/s00216-012-6029-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 03/30/2012] [Accepted: 04/06/2012] [Indexed: 11/30/2022]
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23
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Catherine A, Escoffier N, Belhocine A, Nasri AB, Hamlaoui S, Yéprémian C, Bernard C, Troussellier M. On the use of the FluoroProbe®, a phytoplankton quantification method based on fluorescence excitation spectra for large-scale surveys of lakes and reservoirs. Water Res 2012; 46:1771-1784. [PMID: 22280952 DOI: 10.1016/j.watres.2011.12.056] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 12/20/2011] [Accepted: 12/26/2011] [Indexed: 05/31/2023]
Abstract
Although microscope analysis is very useful for studying phytoplankton community composition, it does not allow for high frequency (spatial and/or temporal) data acquisition. In an attempt to overcome this issue, fluorescence-based approaches that use selective excitation of pigment antennae have spread rapidly. However, the ability of spectral fluorescence to provide accurate estimates of phytoplankton biomass and composition is still debated, and only a few datasets have been tested to date. In this study, we sampled of a wide range of water bodies (n=50) in the Ile-de-France region (North Central France). We used the resulting extensive dataset to assess the ability of the bbe-Moldaenke FluoroProbe II (FP) to estimate phytoplankton community composition in lakes and reservoirs. We demonstrated that FP data yields better estimates of total phytoplankton biovolume than do spectrophotometric chlorophyll a measures and that FP data can be further corrected using the average chlorophyll a to biovolume ratio among phytoplankton groups. Overall, group-specific relationships between FP and biovolume data were consistent. However, we identified a number of cases where caution is required. We found that Euglenophytes are expected to depart from the global FP vs. biovolume relationship of the 'green' group due to varying Fv/Fm and pigment content in response to environmental conditions (photoautotrophic vs. photoheterotrophic growth). Then, it appears necessary to consider the composition of the Chromophytes community in order to obtain a good agreement between both biomass estimation methods. Finally, we confirmed the misattribution toward the 'red' group of phycoerythrin-containing cyanobacteria and the occurrence of a strong scattering in the relationship between the FP vs. biovolume of the 'blue' group that can be partly attributed to the occurrence of large colony-forming cyanobacteria (e.g., Microcystis spp, Aphanizomenon flos-aquae). We propose correcting procedures to improve the quality of data obtained from spectral fluorescence tools in the context of large-scale sampling of lakes and reservoirs.
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Affiliation(s)
- A Catherine
- UMR 7245 MCAM MNHN-CNRS, Equipe Cyanobactéries, Cyanotoxines et Environnement, Muséum National d'Histoire Naturelle, Case 39, 12 rue Buffon, F-75231 Paris Cedex 05, France
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24
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Mouchet MA, Bouvier C, Bouvier T, Troussellier M, Escalas A, Mouillot D. Genetic difference but functional similarity among fish gut bacterial communities through molecular and biochemical fingerprints. FEMS Microbiol Ecol 2011; 79:568-80. [PMID: 22092438 DOI: 10.1111/j.1574-6941.2011.01241.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 08/26/2011] [Accepted: 10/26/2011] [Indexed: 11/26/2022] Open
Abstract
Considering the major involvement of gut microflora in the digestive function of various macro-organisms, bacterial communities inhabiting fish guts may be the main actors of organic matter degradation by fish. Nevertheless, the extent and the sources of variability in the degradation potential of gut bacterial communities are largely overlooked. Using Biolog Ecoplate™ and denaturing gradient gel electrophoresis (DGGE), we explored functional (i.e. the ability to degrade organic matter) and genetic (i.e. identification of DGGE banding patterns) diversity of fish gut bacterial communities, respectively. Gut bacterial communities were extracted from fish species characterized by different diets sampled along a salinity gradient in the Patos-Mirim lagoons complex (Brazil). We found that functional diversity was surprisingly unrelated to genetic diversity of gut bacterial communities. Functional diversity was not affected by the sampling site but by fish species and diet, whereas genetic diversity was significantly influenced by all three factors. Overall, the functional diversity was consistently high across fish individuals and species, suggesting a wide functional niche breadth and a high potential of organic matter degradation. We conclude that fish gut bacterial communities may strongly contribute to nutrient cycling regardless of their genetic diversity and environment.
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Affiliation(s)
- Maud A Mouchet
- UMR 5119 CNRS-UM2-UM1-IRD-Ifremer Ecologie des systèmes marins côtiers, Université Montpellier 2, Montpellier, France.
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25
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Baklouti M, Chevalier C, Bouvy M, Corbin D, Pagano M, Troussellier M, Arfi R. A study of plankton dynamics under osmotic stress in the Senegal River Estuary, West Africa, using a 3D mechanistic model. Ecol Modell 2011. [DOI: 10.1016/j.ecolmodel.2011.04.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Mouillot D, Albouy C, Guilhaumon F, Ben Rais Lasram F, Coll M, Devictor V, Meynard C, Pauly D, Tomasini J, Troussellier M, Velez L, Watson R, Douzery E, Mouquet N. Protected and Threatened Components of Fish Biodiversity in the Mediterranean Sea. Curr Biol 2011; 21:1044-50. [DOI: 10.1016/j.cub.2011.05.005] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 04/20/2011] [Accepted: 05/04/2011] [Indexed: 11/27/2022]
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Boukef Ben Omrane I, El Bour M, Mejri S, Mraouna R, Got P, Troussellier M, Boudabous A. Survival study of enterotoxigenic Escherichia colistrain in seawater and wastewater microcosms. Arch Inst Pasteur Tunis 2011; 88:29-34. [PMID: 23461140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In order to survey osmotic and oligotrophic stress consequence on pathogenic enterobacteria discharged in marine areas, we examined enterotoxigenic Escherichia coli (ETEC) and a reference (Ecoli O126:B16) strains during their survival (47 days) in wastewater microcosms, submerged in natural seawater and maintained in laboratory conditions. The results revealed that the survival time for the two strains was prolonged when bacterial cells were previously incubated in wastewater, with less cellular membrane damage. In addition, the wild clinical E. coli strain showed a better survival capacity than the reference E. coli strain one. For both, we noted some modifications in biochemical profiles relatively to the initial state, notably when they were previously incubated in wastewater microcosm.
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Affiliation(s)
- I Boukef Ben Omrane
- Laboratoire de Microbiologie, Institut National des Sciences et Technologie de la Mer, 2025 Salammbô, Tunisie.
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Boukef I, El Bour M, Al Gallas N, El Bahri O, Mejri S, Mraouna R, Ben Aissa R, Boudabous A, Got P, Troussellier M. Survival of Escherichia coli strains in Mediterranean brackish water in the Bizerte lagoon in northern Tunisia. Water Environ Res 2010; 82:2249-2257. [PMID: 21141386 DOI: 10.2175/106143010x12609736967161] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This study investigated survival and virulence of Escherichia coli strains exposed to natural conditions in brackish water. Two E. coli strains (O126:B16 and O55:B5) were incubated in water microcosms in the Bizerte lagoon in northern Tunisia and exposed for 12 days to natural sunlight in June (231 to 386 W/m2, 26 +/- 1 degrees C, 30 g/L) and in April (227 to 330 W/m2, 17 +/- 1 degrees C, 27 g/L) or maintained in darkness for 21 days (17 +/- 1 degrees C, 27 g/L). The results revealed that sunlight was the most significant inactivating factor (decrease of 3 Ulog within 48 hours for the two strains) compared to salinity and temperature (in darkness). Survival time of the strains was prolonged as they were maintained in darkness. Local strain (E. coli O55:B5) showed better survival capacity (T90 = 52 hours) than E. coli O126:B16 (T90 = 11 h). For both, modifications were noted only for some metabolic activities of carbohydrates hydrolysis. Cytotoxicity of the two strains, tested on Vero cell, was maintained during the period of survival.
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Affiliation(s)
- I Boukef
- National Institute of Sea Sciences and Technology, Laboratory of Microbiology, Salammbô, Tunisia
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Michaud L, Lo Giudice A, Troussellier M, Smedile F, Bruni V, Blancheton J. Phylogenetic characterization of the heterotrophic bacterial communities inhabiting a marine recirculating aquaculture system. J Appl Microbiol 2009; 107:1935-46. [DOI: 10.1111/j.1365-2672.2009.04378.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Catherine A, Troussellier M, Bernard C. Design and application of a stratified sampling strategy to study the regional distribution of cyanobacteria (Ile-de-France, France). Water Res 2008; 42:4989-5001. [PMID: 18945472 DOI: 10.1016/j.watres.2008.09.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 09/08/2008] [Accepted: 09/11/2008] [Indexed: 05/27/2023]
Abstract
This study describes the design and application of a stratified sampling strategy of waterbodies to assess and analyze the distribution of cyanobacteria at a regional scale (Ile-de-France, IDF). Ten groups of hydrographical zones were defined within the IDF on the basis of their anthropogenic and geomorphologic characteristics. Sampling effort (n=50) was then randomly allocated according to the number of waterbodies in each group. This sampling strategy was tested in August 2006, using a field probe to estimate total phytoplankton as well as cyanobacteria biomasses. The sampled waterbodies exhibited a wide range of phytoplankton (< 1-375 microg equiv.Chla L(-1)) and cyanobacteria biomasses (< 1-278 microg equiv.ChlaL(-1)). 72% of the waterbodies in the IDF were classified as eutrophic (42% hypereutrophic), and 24% of the sites studied were dominated by cyanobacteria. Waterbodies connected to hydrographical networks (n=26) showed significantly higher total (p<0.0001; 3.5 times greater) and cyanobacterial (p<0.001, 3.2 times greater) biomasses than the isolated ones (n=24). No significant overall relationship was found through contingency analysis between waterbody trophic status and global land use categories (urban, periurban, and rural) within their hydrographical zones. However, concerning the waterbodies linked to hydrographical networks, the percentage of land covered by forest appeared as a good indicator of phytoplankton and cyanobacterial biomasses. This observation may be a consequence of lower amounts of nutrients being discharged into waterbodies from highly forested hydrological zone than from urban and/or agricultural areas. Our results illustrate a successful means of selecting representative waterbodies to conduct a regional assessment of cyanobacteria distribution using accessible GIS analyses.
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Affiliation(s)
- Arnaud Catherine
- Unité Ecosystèmes et interactions toxiques, USM 0505/EA 4105 MNHN, Muséum National d'Histoire Naturelle, Case 39, 12 rue Buffon, F-75231 Paris Cedex 5, France.
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Catherine A, Quiblier C, Yéprémian C, Got P, Groleau A, Vinçon-Leite B, Bernard CÃ, Troussellier M. Collapse of a Planktothrix agardhii perennial bloom and microcystin dynamics in response to reduced phosphate concentrations in a temperate lake. FEMS Microbiol Ecol 2008; 65:61-73. [DOI: 10.1111/j.1574-6941.2008.00494.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Caro A, Gros O, Got P, De Wit R, Troussellier M. Characterization of the population of the sulfur-oxidizing symbiont of Codakia orbicularis (Bivalvia, Lucinidae) by single-cell analyses. Appl Environ Microbiol 2007; 73:2101-9. [PMID: 17259363 PMCID: PMC1855656 DOI: 10.1128/aem.01683-06] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the characteristics of the sulfur-oxidizing symbiont hosted in the gills of Codakia orbicularis, a bivalve living in shallow marine tropical environments. Special attention was paid to describing the heterogeneity of the population by using single-cell approaches including flow cytometry (FCM) and different microscopic techniques and by analyzing a cell size fractionation experiment. Up to seven different subpopulations were distinguished by FCM based on nucleic acid content and light side scattering of the cells. The cell size analysis of symbionts showed that the symbiotic population was very heterogeneous in size, i.e., ranging from 0.5 to 5 mum in length, with variable amounts of intracellular sulfur. The side-scatter signal analyzed by FCM, which is often taken as a proxy of cell size, was greatly influenced by the sulfur content of the symbionts. FCM revealed an important heterogeneity in the relative nucleic acid content among the subclasses. The larger cells contained exceptionally high levels of nucleic acids, suggesting that these cells contained multiple copies of their genome, i.e., ranging from one copy for the smaller cells to more than four copies for the larger cells. The proportion of respiring symbionts (5-cyano-2,3-ditolyl-terazolium chloride positive) in the bacteriocytes of Codakia revealed that around 80% of the symbionts hosted by Codakia maintain respiratory activity throughout the year. These data allowed us to gain insight into the functioning of the symbionts within the host and to propose some hypotheses on how the growth of the symbionts is controlled by the host.
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Affiliation(s)
- Audrey Caro
- UMR-CNRS 5119, Laboratoire Ecosystèmes Lagunaires, CC 93, Université Montpellier II, 34095 Montpellier Cedex 5, France.
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Cappello S, Caruso G, Zampino D, Monticelli LS, Maimone G, Denaro R, Tripodo B, Troussellier M, Yakimov M, Giuliano L. Microbial community dynamics during assays of harbour oil spill bioremediation: a microscale simulation study. J Appl Microbiol 2007; 102:184-94. [PMID: 17184334 DOI: 10.1111/j.1365-2672.2006.03071.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Microcosm experiments simulating an oil spill event were performed to evaluate the response of the natural microbial community structure of Messina harbour seawater following the accidental load of petroleum. METHODS AND RESULTS An experimental harbour seawater microcosm, supplemented with nutrients and crude oil, was monitored above 15 days in comparison with unpolluted ones (control microcosms). Bacterial cells were counted with a Live/Dead BacLight viability kit; leucine aminopeptidase, beta-glucosidase, alkaline phosphatase, lipase and esterase enzymes were measured using fluorogenic substrates. The microbial community dynamic was monitored by isolation of total RNA, RT-PCR amplification of 16S rRNA, cloning and sequencing. Oil addition stimulated an increase of the total bacterial abundance, leucine aminopeptidase and phosphatase activity rates, as well as a change in the community structure. This suggested a prompt response of micro-organisms to the load of petroleum hydrocarbons. CONCLUSIONS The present study on the viability, specific composition and metabolic characteristics of the microbial community allows a more precise assessment of oil pollution. Both structural and functional parameters offer interesting perspectives as indicators to monitor changes caused by petroleum hydrocarbons. SIGNIFICANCE AND IMPACT OF THE STUDY A better knowledge of microbial structural successions at oil-polluted sites is essential for environmental bioremediation. Data obtained in microcosm studies improve our understanding of natural processes occurring during oil spills.
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Affiliation(s)
- S Cappello
- Istituto per l'Ambiente Marino Costiero (IAMC) IST-CNR Section of Messina, Messina, Italy.
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Berger C, Ba N, Gugger M, Bouvy M, Rusconi F, Couté A, Troussellier M, Bernard C. Seasonal dynamics and toxicity of Cylindrospermopsis raciborskii in Lake Guiers (Senegal, West Africa). FEMS Microbiol Ecol 2006; 57:355-66. [PMID: 16907750 DOI: 10.1111/j.1574-6941.2006.00141.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Cylindrospermopsis raciborskii is a toxic bloom-forming cyanobacterium that occurs at tropical and temperate latitudes. Despite several reports from Africa, no data were previously available about its dynamics or toxic potential there. We therefore carried out a 1-year survey of the dynamics of C. raciborskii in the main water reservoir in Senegal, Lake Guiers. Cylindrospermopsis raciborskii never formed a bloom in this lake during the period studied, but was dominant during the dry season. The only observed bloom-forming species was a diatom, Fragilaria sp., which displayed a seasonal pattern contrary to that exhibited by C. raciborskii. Principal component analysis applied to environmental and phytoplankton data showed that high C. raciborskii biomasses were mainly related to high temperature and water column stability. Tests for C. raciborskii species-related toxicity and/or toxin synthesis were performed on 21 isolated clones. All the strains isolated tested negative in mouse toxicity bioassays, toxin analysis (MS/MS) and tests for known cylindrospermopsin genes (ps, pks). The limited number of isolates studied, and the occurrence of toxic and nontoxic clones in natural cyanobacterial populations, mean that we cannot conclude that there is no C. raciborskii-associated health risk in this drinking water reservoir.
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Affiliation(s)
- Céline Berger
- USM 505 Ecosystèmes et interactions toxiques, Muséum National d'Histoire Naturelle, Paris, France
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Joux F, Lebaron P, Troussellier M. Succession of cellular states in a Salmonella typhimurium population during starvation in artificial seawater microcosms. FEMS Microbiol Ecol 2006. [DOI: 10.1111/j.1574-6941.1997.tb00357.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Baleux B, Alibou J, Troussellier M, Got P. Utilisation du bouillon sélénite F modifié pour dénombrer Salmonella dans les milieux aquatiques. ACTA ACUST UNITED AC 2005. [DOI: 10.7202/705019ar] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ce travail a pour objet de présenter une nouvelle méthode de dénombrement des Salmonella dans différents types d'eaux (de rivière, saumâtre, eaux usées brutes et épurées) basée sur l'utilisation d'un milieu d'enrichissement au sélénite additionné de Novobiocine et de Pril et sur une adaptation de la technique du N.P.P. à l'ensemencement d'échantillons de grands volumes après filtration permettant de quantifier les très faibles concentrations de Salmonella. Les vérifications des performances de cette méthode d'isolement et de quantification sont basées sur l'étude des croissances de différentes souches de Salmonella et d'autres espèces bactériennes dans le milieu d'enrichissement modifié, ainsi que sur les résultats quantitatifs et qualitatifs fournis par cette méthode lorsqu'elle est appliquée à des échantillons d'eau en provenance de l'environnement aquatique. Ces résultats montrent notamment que la méthode proposée est suffisamment sensible pour détecter 1 à 2 Salmonella dans 10 litres d'eau analysée et qu'elle ne parait pas exclure de sérotypes, du moins parmi ceux les plus fréquemment isolés en France. L'efficacité de la méthode standardisée API Z pour l'identification enzymatique du genre Salmonella a été également testée en référence aux résultats de la sérotypie.
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Denaro R, D'Auria G, Di Marco G, Genovese M, Troussellier M, Yakimov MM, Giuliano L. Assessing terminal restriction fragment length polymorphism suitability for the description of bacterial community structure and dynamics in hydrocarbon-polluted marine environments. Environ Microbiol 2005; 7:78-87. [PMID: 15643938 DOI: 10.1111/j.1462-2920.2004.00685.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The distribution of bacterial communities terminal restriction fragment length polymorphism (T-RFLP) fingerprint patterns was evaluated at three proximal hydrocarbon-contaminated sites located within the harbour of Messina. In order to analyse the short-term variability of the individual terminal restriction fragment (T-RF) patterns, water samples were collected at the three sites on three occasions within 3 months (T(0), T(90) and T(91)). Four sample sizes, from 50 to 1000 ml for each collected sample, were analysed separately (36 total analysed samples) to evaluate the relationship between the sample size and the bacterial diversity estimates. The dominant T-RF groups mostly belonged to signatures of putative hydrocarbon-degrading bacteria, as revealed by the virtual analysis of the obtained bands. In order to test whether significant differences were occurring between the analysed samples, the Kruskal-Wallis non-parametric test was applied to the T-RF data set. Neither significant influence of the sample size nor short spatial variability within the three sampled sites was detected for each sampling time. On the contrary, significant temporal changes in the diversity of the bacterial communities were observed. These results were confirmed by the non-metric multidimensional scales (nMDS) analysis of the whole set of samples, which indicated three main groups corresponding to the three different sampling times. In summary, the T-RFLP technique, although a polymerase chain reaction-based method, proved to be a suitable technique for monitoring polluted marine environments, typically characterized by low diversity and high relative abundances of a few dominant groups.
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Affiliation(s)
- R Denaro
- Istituto per l'Ambiente Marino Costiero (IAMC), sezione di Messina, Consiglio Nazionale delle Ricerche (CNR), Spianata S. Raineri 86, 98122 Messina, Italy.
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Troussellier M, Got P, Bouvy M, M'Boup M, Arfi R, Lebihan F, Monfort P, Corbin D, Bernard C. Water quality and health status of the Senegal River estuary. Mar Pollut Bull 2004; 48:852-862. [PMID: 15111032 DOI: 10.1016/j.marpolbul.2003.10.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Senegal River estuary was sampled in May 2002 to get the first data on both the trophic and sanitary status of the water of the main river of the northwest African coast. Several physical, chemical and microbiological variables were measured twice along a transect. Inorganic nutrient concentrations were low while phytoplanktonic abundances (0.58-1.8 x 10(5) cells ml(-1)), bacterial abundances (0.27-8.1 x 10(7) cells ml(-1)), activity (22-474 pmol l(-1) h(-1)), were among the highest recorded in such ecosystems. Microbiological variables revealed a eutrophicated status for this estuary. Largest abundances of fecal contamination bacterial indicators were only detected in localized areas (Saint-Louis city and surrounding areas). The apparent good survival of fecal indicator bacteria in the estuarine waters despite a long residence time (4-5 days) has been evaluated by complementary survival experiments. Exposed to a salinity gradient, a local Escherichia coli strain showed a significantly better survival than those of an E. coli reference strain.
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Affiliation(s)
- M Troussellier
- Laboratoire Ecosystèmes lagunaires, UMR 5119 CNRS, Université Montpellier II, Case 093, Place E. Bataillon, 34095 Montpellier 5, France.
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Fiandrino A, Martin Y, Got P, Bonnefont JL, Troussellier M. Bacterial contamination of Mediterranean coastal seawater as affected by riverine inputs: simulation approach applied to a shellfish breeding area (Thau lagoon, France). Water Res 2003; 37:1711-1722. [PMID: 12697215 DOI: 10.1016/s0043-1354(02)00573-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Consequences of short-term changes in thermotolerant coliform loads on their spatio-temporal distribution in a Mediterranean lagoon with large-scale mollusk farming (Thau lagoon, France) were explored using a simulation approach. Simulations were based on bacterial transport and survival coupled models forced by the input of bacterial loads from the two main rivers (Vène and Pallas) that flow into the lagoon. Different flow types (reference, sudden and constant), bringing the same bacterial load, were considered and subsequent spatial and temporal bacterial contamination of lagoon surface water and shellfish was estimated. Simulation results showed that as long as loads were high, hydrodynamical processes governed the distribution of bacterial abundance in receiving areas. As soon as loads decreased or when time supply increased, biological die-off processes became dominant. Bacterial contamination of shellfish induced by the different flow types appeared to depend on the receiving area. In the case of Pallas River area, a sudden input of bacteria led to a high bacterial contamination of shellfish but only during a short period ( approximately 1 day). A constant input of the same amount of bacteria induced a lower but significant contamination during all the simulation period (10 days). On the contrary, bacterial inputs from the Vène River led to shellfish contamination only when bacteria were delivered through a flood event. Exposure time of bacteria to adverse environmental conditions appeared to be the main explanation to the above-mentioned differences. Consequences of our results in terms of environmental management strategy were discussed.
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Affiliation(s)
- A Fiandrino
- UMR 5119 CNRS Université Montpellier II, Lab. Ecosystèmes lagunaires, 34095 Montpellier Cedex 05, France
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Morris CE, Bardin M, Berge O, Frey-Klett P, Fromin N, Girardin H, Guinebretière MH, Lebaron P, Thiéry JM, Troussellier M. Microbial biodiversity: approaches to experimental design and hypothesis testing in primary scientific literature from 1975 to 1999. Microbiol Mol Biol Rev 2002; 66:592-616, table of contents. [PMID: 12456784 PMCID: PMC134657 DOI: 10.1128/mmbr.66.4.592-616.2002] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Research interest in microbial biodiversity over the past 25 years has increased markedly as microbiologists have become interested in the significance of biodiversity for ecological processes and as the industrial, medical, and agricultural applications of this diversity have evolved. One major challenge for studies of microbial habitats is how to account for the diversity of extremely large and heterogeneous populations with samples that represent only a very small fraction of these populations. This review presents an analysis of the way in which the field of microbial biodiversity has exploited sampling, experimental design, and the process of hypothesis testing to meet this challenge. This review is based on a systematic analysis of 753 publications randomly sampled from the primary scientific literature from 1975 to 1999 concerning the microbial biodiversity of eight habitats related to water, soil, plants, and food. These publications illustrate a dominant and growing interest in questions concerning the effect of specific environmental factors on microbial biodiversity, the spatial and temporal heterogeneity of this biodiversity, and quantitative measures of population structure for most of the habitats covered here. Nevertheless, our analysis reveals that descriptions of sampling strategies or other information concerning the representativeness of the sample are often missing from publications, that there is very limited use of statistical tests of hypotheses, and that only a very few publications report the results of multiple independent tests of hypotheses. Examples are cited of different approaches and constraints to experimental design and hypothesis testing in studies of microbial biodiversity. To prompt a more rigorous approach to unambiguous evaluation of the impact of microbial biodiversity on ecological processes, we present guidelines for reporting information about experimental design, sampling strategies, and analyses of results in publications concerning microbial biodiversity.
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Affiliation(s)
- Cindy E Morris
- Station de Pathologie Végétale, Station de Technologie de Produits Végétaux, France.
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Abstract
BACKGROUND The present review is based on the identification of four major environmental crises that have been approached from a biological oceanographic viewpoint. These crises are the release of contaminants in near shore marine waters, the collapse of marine resources that were renewable until recently, the loss of biodiversity, and global climate change METHODS The review examines the contribution of cytometry-based biological oceanography to the resolution of the four environmental crises. Using a database of 302 papers, flow cytometric (FCM) studies in biological oceanography over the 1989--1999 decade are examined. Future biological oceanographic applications of FCM are discussed. RESULTS Most of the published FCM oceanographic studies focus on phytoplankton and bacterioplankton. Analysis of our 1989-1999 database shows the predominance of studies dedicated to phytoplankton (77%), followed by heterotrophic bacteria (21%). The latter progressively increased over the last decade, together with the improved understanding of the biogeochemical and trophic roles of marine bacteria. Most studies on these two microorganisms were conducted in vitro until 1996, after which the trend reversed in favor of in situ research. The most investigated areas were those with major international sampling efforts, related to the changing climate. Concerning environmental topics, 62% of papers on phytoplankton and bacterioplankton focused on the structure of microbial communities and fluxes (e.g., production, grazing); this provides the basis for biological oceanographic studies on resources and climate change. CONCLUSIONS Future progress in the biological oceanographic use of FCM will likely fall into two categories, i.e., applications where FCM will be combined with the development of other methods and those where FCM will be the main analytical tool. It is expected that FCM and other cytometric approaches will improve the ability of biological oceanography to address the major environmental challenges that are confronting human societies.
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Affiliation(s)
- L Legendre
- Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, France.
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Abstract
BACKGROUND In the past decade, flow cytometry has become a useful and precise alternative to microscopic bacterial cell counts in aquatic samples. However, little evidence of its usefulness for the evaluation of bacterial biovolumes has emerged in from the literature. METHODS The light scattering and cell volume of starved bacterial strains and natural bacterial communities from the Black Sea were measured by flow cytometry and epifluorescence microscopy, respectively, in order to establish a relationship between light scattering and cell volume. RESULTS With the arc-lamp flow cytometer, forward angle light scatter (FALS) was related to cell size in both the starved strains and natural communities, although regression parameters differed. We tested the predictive capacity of the FALS verous cell size relationship in a bacterial community from the North Sea. That analysis showed that a reliable bacterial biovolume prediction of a natural bacterial community can be obtained from FALS using a model generated from natural bacterial community data. CONCLUSIONS Bacterial biovolume is likely to be related to FALS measurements. It is possible to establish a generally applicable model derived from natural bacterial assemblages for flow cytometric estimation of bacterial biovolumes by light scatter.
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Affiliation(s)
- T Bouvier
- Ecologie des Systèmes Aquatiques, Université Libre de Bruxelles, Brussels, Belgium
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Schäfer H, Bernard L, Courties C, Lebaron P, Servais P, Pukall R, Stackebrandt E, Troussellier M, Guindulain T, Vives-Rego J, Muyzer G. Microbial community dynamics in Mediterranean nutrient-enriched seawater mesocosms: changes in the genetic diversity of bacterial populations. FEMS Microbiol Ecol 2001; 34:243-253. [PMID: 11137604 DOI: 10.1111/j.1574-6941.2001.tb00775.x] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
A mesocosm experiment was performed to study the influence of nutrients on activity and diversity of bacterial assemblages from the Mediterranean Sea. Changes in the diversity of the predominant bacterial populations were monitored by DGGE fingerprinting of PCR products derived from 16S rRNA encoding genes. Fluctuations in the diversity of the most active populations was inferred by performing the DGGE fingerprinting on the basis of the cellular rRNA after reverse transcription and PCR amplification. DNA-derived DGGE patterns obtained from duplicate control and nutrient-enriched mesocosms showed differences in the development of the bacterial communities between control and nutrient-enriched experimental mesocosms. Multidimensional scaling analysis of the DNA-derived DGGE fingerprints indicated that duplicate treatments were reproducible. DNA- and RNA-derived DGGE fingerprints of bacterial assemblages changed over time, showing that the composition of the bacterial assemblages, as well as the most active bacterial populations changed during different phases of the incubation. Sequences of predominant DGGE bands in RNA-derived patterns were similar to 16S rRNA gene sequences of members of the alpha-, gamma- and delta-Proteobacteria and of the Cytophaga-Flavobacterium-Bacteroides phylum (CFB). Bands corresponding to Ruegeria-like bacteria and members of the CFB became especially dominant during the course of incubation, suggesting that these populations were important contributors to bacterial production and activity in the post-grazing phase of the experiment.
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Lebaron P, Servais P, Troussellier M, Courties C, Muyzer G, Bernard L, Schäfer H, Pukall R, Stackebrandt E, Guindulain T, Vives-Rego J. Microbial community dynamics in Mediterranean nutrient-enriched seawater mesocosms: changes in abundances, activity and composition. FEMS Microbiol Ecol 2001; 34:255-266. [PMID: 11137605 DOI: 10.1111/j.1574-6941.2001.tb00776.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Quantitative and qualitative changes in bacterial communities from the Mediterranean Sea were compared in duplicate batch mesocosms with or without addition of inorganic nutrients. Methods including traditional microbial ecology techniques, molecular biology and flow cytometry were combined to determine abundances, production, cell size, activity, culturability and taxonomic diversity of bacterial cells. Addition of nutrients and confinement resulted in an increase of bacterial densities which were rapidly controlled by protozoan grazing. Changes in bacterial activity and morphology were observed during the growth phase of bacteria and under grazing pressure. The proportion of medium-size and culturable cells increased during the growth phase. These cells were preferentially consumed by grazers resulting in a strong limitation of bacterial production. As a consequence of the grazing pressure, large cells were produced and contributed to the remaining bacterial productivity after grazing. Grazing had an effect on the taxonomic composition of bacterial communities by preferentially eliminating gamma-Proteobacteria, alpha-Proteobacteria were preserved. It seems that some species from the genera Ruegeria and Cytophaga may have developed defence strategies to escape predation.
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Bernard L, Courties C, Servais P, Troussellier M, Petit M, Lebaron P. Relationships among Bacterial Cell Size, Productivity, and Genetic Diversity in Aquatic Environments using Cell Sorting and Flow Cytometry. Microb Ecol 2000; 40:148-158. [PMID: 11029083 DOI: 10.1007/s002480000046] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The study of relationships between cell size and productivity is of key importance in microbial ecology to understand which members of natural aquatic communities are responsible for the overall activity and/or productivity. Flow sorting of microorganisms from different environmental samples was used to analyze the activity of bacterial cells depending on their biovolume. Bacterial cells from five different natural samples taken along the Mediterranean coast including fresh- and seawaters were incubated with tritiated leucine, then stained with SYTO 13 and sorted by flow cytometry according to their average side-angle-scattered (SSC) light. In all samples, a bell-shaped relationship was found between cell biovolume and activity, whereas activity of a given cell-size class varied between samples. In contrast, an inverse relationship was found between biovolumes and abundances. These results suggest that medium-sized cells with highest growth rates are probably submitted to intense grazing. For one sample, bacteria within five different size classes were sorted and the genetic diversity of cells within each sorted size class and that of the whole community were analyzed by the denaturing gradient gel electrophoresis (DGGE) method. The genetic diversity, as determined at the community level was highly represented into the pool of small cells, whereas only few species were present into larger cell subpopulations. The results suggest that only a few genotypes may be dominant within the largest and most productive cells. Furthermore, cell size polymorphism as well as heterogeneous cellular activities were found within some species.
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Affiliation(s)
- L Bernard
- Observatoire Océanologique, Université Pierre et Marie Curie, UMR-7621 and 7628 CNRS, Institut National des Sciences de l'Univers BP 44, F-66651 Banyuls-sur-Mer Cedex, France
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Servais P, Courties C, Lebaron P, Troussellier M. Coupling Bacterial Activity Measurements with Cell Sorting by Flow Cytometry. Microb Ecol 1999; 38:180-189. [PMID: 10441710 DOI: 10.1007/s002489900160] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
> Abstract A new procedure to investigate the relationship between bacterial cell size and activity at the cellular level has been developed; it is based on the coupling of radioactive labeling of bacterial cells and cell sorting by flow cytometry after SYTO 13 staining. Before sorting, bacterial cells were incubated in the presence of tritiated leucine using a procedure similar to that used for measuring bacterial production by leucine incorporation and then stained with SYTO 13. Subpopulations of bacterial cells were sorted according to their average right-angle light scatter (RALS) and fluorescence. Average RALS was shown to be significantly related to the average biovolume. Experiments were performed on samples collected at different times in a Mediterranean seawater mesocosm enriched with nitrogen and phosphorus. At four sampling times, bacteria were sorted in two subpopulations (cells smaller and larger than 0.25 µm(3)). The results indicate that, at each sampling time, the growth rate of larger cells was higher than that of smaller cells. In order to confirm this tendency, cell sorting was performed on six subpopulations differing in average biovolume during the mesocosm follow-up. A clear increase of the bacterial growth rates was observed with increasing cell size for the conditions met in this enriched mesocosm.http://link.springer-ny.com/link/service/journals/00248/bibs/38n2p180.html
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Affiliation(s)
- P Servais
- Groupe de Microbiologie des Milieux Aquatiques, Université Libre de Bruxelles, Campus de la Plaine, CP 221, Boulevard du Triomphe, B-1050 Bruxelles, Belgium
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Troussellier M, Courties C, Lebaron P, Servais P. Flow cytometric discrimination of bacterial populations in seawater based on SYTO 13 staining of nucleic acids. FEMS Microbiol Ecol 1999. [DOI: 10.1111/j.1574-6941.1999.tb00623.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Martin Y, Troussellier M, Bonnefont JL. Adaptative responses of E. coli to marine environmental stresses: a modelling approach based on viability and dormancy concepts. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0399-1784(99)80018-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Joux F, Lebaron P, Troussellier M. Changes in Cellular States of the Marine Bacterium Deleya aquamarina under Starvation Conditions. Appl Environ Microbiol 1997; 63:2686-94. [PMID: 16535646 PMCID: PMC1389201 DOI: 10.1128/aem.63.7.2686-2694.1997] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, we have used different fluorescent dyes and techniques to characterize the heterogeneity and changes of the physiological states encountered by the marine bacterium Deleya aquamarina during a 92-day starvation survival experiment at 20 and 5(deg)C. Changes of physiological states were investigated on a single-cell basis by flow cytometry and epifluorescence microscopy in conjunction with fluorescent dyes specific for various cellular functions and constituents. Heterogeneities within populations with regard to functions (respiration, substrate responsiveness, enzymatic activity, and cytoplasmic membrane permeability), constituent (DNA), and cell volume (light scatter) were compared to the evolution of viable plate counts (CFU). At 20(deg)C, CFU changes were divided into three stages corresponding to stability up to day 13 followed by a rapid drop between days 13 and 42 and then by stabilization at a level of 10 to 20% during the remaining survival period. Most of the cellular fractions showing a metabolic activity were close to the evolution of the culturable cells, suggesting the absence of viable but nonculturable cells. On the other hand, cells with selective cytoplasmic membrane permeability but without any metabolic activity were observed, and this stage was followed by DNA alteration occurring at different rates after the loss of membrane cytoplasmic permeability. We observed a greater maintenance of culturability, physiological functions, DNA, and cellular volume at the lower temperature. These results have different ecological implications from both methodological and conceptual viewpoints.
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