Journal: Environmental Microbiology

Abbreviation

Environ Microbiol,

Publisher

Wiley

Journal Volumes

ISSN

1462-2912
1462-2920

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2014 - 2019112020 - 202516
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Publications 1 - 10 of 27
  • Impact of manipulation of glycerol/diol dehydratase activity on intestinal microbiota ecology and metabolism
    Item type: Journal Article
    Ramirez Garcia, Alejandro; Zhang, Jianbo; Greppi, Anna; et al. (2021)
    Environmental Microbiology
    Glycerol/diol dehydratases (GDH) are enzymes that catalyse the production of propionate from 1,2‐propanediol, and acrolein from glycerol. Acrolein reacts with dietary carcinogenic heterocyclic amines (HCA), reducing HCA mutagenicity, but is itself also an antimicrobial agent and toxicant. Gut microbial GDH activity has been suggested as an endogenous acrolein source; however, there is limited information on the potential of the intestinal microbiota to have GDH activity, and what impact it can have on the intestinal ecosystem and host health. We hypothesized that GDH activity of gut microbiota is determined by the abundance and distribution of GDH‐active taxa and can be enhanced by supplementation of the GDH active Anaerobutyricum hallii, and tested this hypothesis combining quantitative profiling of gdh, model batch fermentations, microbiota manipulation, and kinetic modelling of acrolein formation. Our results suggest that GDH activity is a common trait of intestinal microbiota shared by a few taxa, which was dependent on overall gdh abundance. Anaerobutyricum hallii was identified as a key taxon in GDH metabolism, and its supplementation increased the rate of GDH activity and acrolein release, which enhanced the transformation of HCA and reduced fermentation activity. The findings of this first systematic study on acrolein release by intestinal microbiota indicate that dietary and microbial modulation might impact GDH activity, which may influence host health. © 2021 Society for Applied Microbiology and John Wiley & Sons Ltd.
  • Diet shapes cold-water corals bacterial communities
    Item type: Journal Article
    Galand, Pierre E.; Remize, Marine; Meistertzheim, Anne-Leila; et al. (2020)
    Environmental Microbiology
  • Marked seasonality of aerobic anoxygenic phototrophic bacteria in the coastal NW Mediterranean Sea as revealed by cell abundance, pigment concentration and pyrosequencing of pufM gene
    Item type: Journal Article
    Ferrera, Isabel; Borrego, Carles M.; Salazar Guiral, Guillem; et al. (2014)
    Environmental Microbiology
  • Phylogenetically closely related pseudomonads isolated from arthropods exhibit differential insect-killing abilities and genetic variations in insecticidal factors
    Item type: Journal Article
    Vesga, Pilar; Augustiny, Eva; Keel, Christoph; et al. (2021)
    Environmental Microbiology
    Strains belonging to the Pseudomonas protegens and Pseudomonas chlororaphis species are able to control soilborne plant pathogens and to kill pest insects by producing virulence factors such as toxins, chitinases, antimicrobials or two-partner secretion systems. Most insecticidal Pseudomonas described so far were isolated from roots or soil. It is unknown whether these bacteria naturally occur in arthropods and how they interact with them. Therefore, we isolated P. protegens and P. chlororaphis from various healthy insects and myriapods, roots and soil collected in an agricultural field and a neighbouring grassland. The isolates were compared for insect killing, pathogen suppression and host colonization abilities. Our results indicate that neither the origin of isolation nor the phylogenetic position mirror the degree of insecticidal activity. Pseudomonas protegens strains appeared homogeneous regarding phylogeny, biocontrol and insecticidal capabilities, whereas P. chlororaphis strains were phylogenetically and phenotypically more heterogenous. A phenotypic and genomic analysis of five closely related P. chlororaphis isolates displaying varying levels of insecticidal activity revealed variations in genes encoding insecticidal factors that may account for the reduced insecticidal activity of certain isolates. Our findings point towards an adaption to insects within closely related pseudomonads and contribute to understand the ecology of insecticidal Pseudomonas.
  • Vibrio natriegens: an ultrafast-growing marine bacterium as emerging synthetic biology chassis
    Item type: Journal Article
    Hoff, Josef; Daniel, Benjamin; Stukenberg, Daniel; et al. (2020)
    Environmental Microbiology
    The marine bacterium Vibrio natriegens is the fastest-growing non-pathogenic bacterium known to date and is gaining more and more attention as an alternative chassis organism to Escherichia coli. A recent wave of synthetic biology efforts has focused on the establishment of molecular biology tools in this fascinating organism, now enabling exciting applications – from speeding up our everyday laboratory routines to increasing the pace of biotechnological production cycles. In this review, we seek to give a broad overview on the literature on V. natriegens, spanning all the way from its initial isolation to its latest applications. We discuss its natural ecological niche and interactions with other organisms, unveil some of its extraordinary traits, review its genomic organization and give insight into its diverse metabolism – key physiological insights required to further develop this organism into a synthetic biology chassis. By providing a comprehensive overview on the established genetic tools, methods and applications we highlight the current possibilities of this organism, but also identify some of the gaps that could drive future lines of research, hopefully stimulating the growth of the V. natriegens research community. © 2020 Society for Applied Microbiology and John Wiley & Sons Ltd.
  • Mycorrhiza-induced mycocypins of Laccaria bicolor are potent protease inhibitors with nematotoxic and collembola antifeedant activity
    Item type: Journal Article
    Plett, Jonathan M.; Sabotič, Jerica; Vogt, Eva; et al. (2022)
    Environmental Microbiology
    Fungivory of mycorrhizal hyphae has a significant impact on fungal fitness and, by extension, on nutrient transfer between fungi and host plants in natural ecosystems. Mycorrhizal fungi have therefore evolved an arsenal of chemical compounds that are hypothesized to protect the hyphal tissues from being eaten, such as the protease inhibitors mycocypins. The genome of the ectomycorrhizal fungus Laccaria bicolor has an unusually high number of mycocypin-encoding genes. We have characterized the evolution of this class of proteins, identified those induced by symbiosis with a host plant and characterized the biochemical properties of two upregulated L. bicolor mycocypins. More than half of L. bicolor mycocypin-encoding genes are differentially expressed during symbiosis or fruiting body formation. We show that two L. bicolor mycocypins that are strongly induced during symbiosis are cysteine protease inhibitors and exhibit similar but distinct localization in fungal tissues at different developmental stages and during interaction with a host plant. Moreover, we show that these L. bicolor mycocypins have toxic and feeding deterrent effect on nematodes and collembolans, respectively. Therefore, L. bicolor mycocypins may be part of a mechanism by which this species deters grazing by different members of the soil food web.
  • Nanotube-mediated cross-feeding couples the metabolism of interacting bacterial cells
    Item type: Journal Article
    Shitut, Shraddha; Ahsendorf, Tobias; Pande, Samay; et al. (2019)
    Environmental Microbiology
  • Life in the dark: far‐red absorbing cyanobacteria extend photic zones deep into terrestrial caves
    Item type: Journal Article
    Behrendt, Lars; Trampe, Erik L.; Nord, Nadia B.; et al. (2020)
    Environmental Microbiology
  • Quantity Versus Quality: Links Between Soil Organic Matter and Bacterial Community Composition Along a Geoclimatic Gradient
    Item type: Journal Article
    Wasner, Daniel; Han, Xingguo; Schnecker, Joerg; et al. (2025)
    Environmental Microbiology
    Soil organic matter (SOM) quantity drives soil bacterial community composition from the regional to global scale. Qualitative characteristics of SOM are known to affect soil bacterial communities in manipulation experiments. However, it remains unresolved how strongly SOM characteristics affect soil bacterial community composition at the macroscale. Here, we investigated how quantity versus qualitative characteristics of SOM shape community composition along a biogeochemical gradient of grassland soils. We assessed relative abundance patterns of soil bacteria and characterised SOM based on scalable methods. Soils with higher SOM content (along a continuum between 0.6% and 18.7% SOC) and acidic pH (along a continuum between pH 4.1-6.7) hosted fewer narrowly distributed taxa (i.e., taxa occurring in few sites) and therefore had lower bacterial alpha diversity. We could explain a larger fraction of bacterial community composition (up to 59.6% of 16S rRNA reads) in these soils. Consequently, we understand community composition in low-SOM soils less than in high-SOM soils, because the drivers of narrowly distributed taxa remain poorly understood. Qualitative SOM characteristics did not strongly affect biogeographical patterns of widely distributed soil bacterial taxa. This suggests that broad aspects of SOM quality do not dominate soil bacterial community composition at the investigated macroscale.
  • Asexual reproductive potential trumps virulence as a predictor of competitive ability in mixed infections
    Item type: Journal Article
    Bernasconi, Alessio; Alassimone, Julien; McDonald, Bruce A.; et al. (2022)
    Environmental Microbiology
    Natural infections frequently involve several co-infecting pathogen strains. These mixed infections can affect the extent of the infection, the transmission success of the pathogen and the eventual epidemic outcome. To date, few studies have investigated how mixed infections affect transmission between hosts. Zymoseptoria tritici is a highly diverse wheat pathogen in which multiple strains often coexist in the same lesion. Here we demonstrate that the most competitive strains often exclude their competitors during serial passages of mixed infections. The outcome of the competition depended on both the host genotype and the genotypes of the competing pathogen strains. Differences in virulence among the strains were not associated with competitive advantages during transmission, while differences in reproductive potential had a strong effect on strain competitive ability. Overall, our findings suggest that host specialization is determined mainly by the ability to successfully transmit offspring to new hosts during mixed infections.
Publications 1 - 10 of 27