Publications by authors named "Philippe N Bertin"

Stenotrophomonas maltophilia strain 1800 was isolated from the effluent of an industrial oil refinery in Algeria. Its genome was sequenced using Illumina MiSeq (2 × 150-bp read pairs) and Oxford Nanopore (long reads) technologies and assembled using Unicycler. It is composed of one chromosome of 4.

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Owing to their roles in the arsenic (As) biogeochemical cycle, microorganisms and plants offer significant potential for developing innovative biotechnological applications able to remediate As pollutions. This possible use in bioremediation processes and phytomanagement is based on their ability to catalyse various biotransformation reactions leading to, e.g.

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A novel bacterial strain was isolated from industrially contaminated waste water. In the presence of crude oil, this strain was shown to reduce the rate of total petroleum hydrocarbons (TPH) up to 97.10% in 24 h.

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sp. strain Nx66 was isolated from waters contaminated by petrochemical effluents collected in Algeria. Its genome was sequenced using Illumina MiSeq (2 × 150-bp read pairs) and Oxford Nanopore (long reads) technologies and was assembled using Unicycler.

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Amongst iron-oxidizing bacteria playing a key role in the natural attenuation of arsenic in acid mine drainages (AMDs), members of the Ferrovum genus were identified in mine effluent or water treatment plants, and were shown to dominate biogenic precipitates in field pilot experiments. In order to address the question of the in situ activity of the uncultivated Ferrovum sp. CARN8 strain in the Carnoulès AMD, we assembled its genome using metagenomic and metatranscriptomic sequences and we determined standardized expression values for protein-encoding genes.

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Article Synopsis
  • Microorganisms are key players in biogeochemical cycles and have potential for biotechnological improvements to combat pollution.
  • Their effectiveness in bioremediation comes from their ability to break down toxic substances and facilitate various chemical reactions.
  • Advancements in genomics can enhance our understanding of these metabolic processes and help develop effective strategies for remediating pollutants like arsenic, which poses a significant health risk globally.
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Arsenic, which is a major contaminant of many aquatic ecosystems worldwide, is responsible for serious public health issues. However, life has evolved various strategies for coping with this toxic element. In particular, prokaryotic organisms have developed processes enabling them to resist and metabolize this chemical.

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Arsenic is a toxic metalloid known to generate an important oxidative stress in cells. In the present study, we focused our attention on an alga related to the genus Coccomyxa, exhibiting an extraordinary capacity to resist high concentrations of arsenite and arsenate. The integrated analysis of high-throughput transcriptomic data and non-targeted metabolomic approaches highlighted multiple levels of protection against arsenite.

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The acid mine drainage (AMD) in Carnoulès (France) is characterized by the presence of toxic metals such as arsenic. Several bacterial strains belonging to the Thiomonas genus, which were isolated from this AMD, are able to withstand these conditions. Their genomes carry several genomic islands (GEIs), which are known to be potentially advantageous in some particular ecological niches.

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Article Synopsis
  • Acid mine drainage (AMD) poses a toxic threat to life due to elements like arsenic, but Thiomonas bacteria can survive by oxidizing arsenite.
  • * Researchers sequenced the genomes of six Thiomonas isolates from the Carnoulès AMD to understand their adaptive traits, comparing them to other strains like Tm. arsenitoxydans and Tm. intermedia.
  • * The analysis revealed significant genomic rearrangements and over 20 genomic islands across the strains, indicating that arsenic-related genes have evolved differently, enhancing their survival in arsenic-rich environments.
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Pseudomonas xanthomarina S11 is an arsenite-oxidizing bacterium isolated from an arsenic-contaminated former gold mine in Salsigne, France. This bacterium showed high resistance to arsenite and was able to oxidize arsenite to arsenate at concentrations up to 42.72 mM As[III].

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Article Synopsis
  • Recent advances in microbial ecology enable the study of microorganisms in their natural environments without the need for lab cultivation, tapping into vast uncultivable microbial communities.
  • Environmental proteomics has become a valuable tool alongside metagenomics, revealing important metabolic functions and how organisms adapt to their environments.
  • The review discusses various proteomic methods used to explore the structure and function of microbial communities and highlights recent studies demonstrating these approaches.
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Deciphering the biotic and abiotic factors that control microbial community structure over time and along an environmental gradient is a pivotal question in microbial ecology. Carnoulès mine (France), which is characterized by acid waters and very high concentrations of arsenic, iron, and sulfate, provides an excellent opportunity to study these factors along the pollution gradient of Reigous Creek. To this end, biodiversity and spatiotemporal distribution of bacterial communities were characterized using T-RFLP fingerprinting and high-throughput sequencing.

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Arsenic is a toxic metalloid known to cause multiple and severe cellular damages, including lipid peroxidation, protein misfolding, mutagenesis and double and single-stranded DNA breaks. Thus, exposure to this compound is lethal for most organisms but some species such as the photosynthetic protist Euglena mutabilis are able to cope with very high concentrations of this metalloid. Our comparative transcriptomic approaches performed on both an arsenic hypertolerant protist, i.

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Article Synopsis
  • The bacterium Halomonas sp. strain A3H3 was isolated from polluted sediments in l'Estaque harbor, Marseille, France, and is known for its ability to tolerate arsenite.
  • Its genome consists of a large chromosome measuring 5,489,893 base pairs and a plasmid that is 157,085 base pairs long.
  • This research contributes to our understanding of how certain bacteria can survive in contaminated environments.
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Microorganisms dwelling in sediments have a crucial role in biogeochemical cycles and are expected to have a strong influence on the cycle of arsenic, a metalloid responsible for severe water pollution and presenting major health risks for human populations. We present here a metagenomic study of the sediment from two harbours on the Mediterranean French coast, l'Estaque and St Mandrier. The first site is highly polluted with arsenic and heavy metals, while the arsenic concentration in the second site is below toxicity levels.

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Arsenic is widespread in the environment and its presence is a result of natural or anthropogenic activities. Microbes have developed different mechanisms to deal with toxic compounds such as arsenic and this is to resist or metabolize the compound. Here, we present the first reference set of genomic, transcriptomic and proteomic data of an Alphaproteobacterium isolated from an arsenic-containing goldmine: Rhizobium sp.

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Arsenic causes threats for environmental and human health in numerous places around the world mainly due to its carcinogenic potential at low doses. Removing arsenic from contaminated sites is hampered by the occurrence of several oxidation states with different physicochemical properties. The actual state of arsenic strongly depends on its environment whereby microorganisms play important roles in its geochemical cycle.

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Here, we report the draft genome sequence of Desulfotomaculum hydrothermale, a sulfate-reducing, spore-forming bacterium isolated from a Tunisian hot spring. The genome is composed of 2.7 Mb, with a G+C content of 49.

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Article Synopsis
  • Polyadenylation is a process that helps eliminate defective RNA and is important for gene expression in both eukaryotes and prokaryotes, like E. coli.
  • In studies, E. coli strains without poly(A)polymerase I (PAP I) showed reduced flagellin levels and lower transcription of flagellar biosynthesis genes, suggesting that PAP I positively influences their expression.
  • Despite the reduced expression of flagellar genes in the mutant strains, there were no major defects in flagella synthesis or swimming speed, although they were less motile on soft agar and more sensitive to antibiotics, hinting at PAP I's role in helping bacteria adjust to environmental challenges.
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Euglena mutabilis is a photosynthetic protist found in acidic aquatic environments such as peat bogs, volcanic lakes and acid mine drainages (AMDs). Through its photosynthetic metabolism, this protist is supposed to have an important role in primary production in such oligotrophic ecosystems. Nevertheless, the exact contribution of E.

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Biofilms represent the most common microbial lifestyle, allowing the survival of microbial populations exposed to harsh environmental conditions. Here, we show that the biofilm development of a bacterial species belonging to the Thiomonas genus, frequently found in arsenic polluted sites and playing a key role in arsenic natural remediation, is markedly modified when exposed to subinhibitory doses of this toxic element. Indeed, arsenite [As(III)] exposure led to a considerable impact on biofilm maturation by strongly increasing the extracellular matrix synthesis and by promoting significant cell death and lysis within microcolonies.

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