Clément OffretUniversité Bretagne Sud | UBS · LBCM - Laboratoire de Biotechnologie et Chimie Marines
Clément Offret
PhD Microbiology & Biochemistry
About
19
Publications
5,364
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273
Citations
Citations since 2017
Introduction
My research interests involve the exploration of holobiont in marine invertebrates and how good-guy and bad-guy from microbiota affect host homeostasis.
Additional affiliations
November 2021 - present
December 2019 - October 2021
Position
- PostDoc Position
Description
- Biopreservation using marine bacteria in seafood
May 2018 - November 2019
Position
- PostDoc Position
Description
- Bacterial diversity of digestive microbiota from bivalves • Digestive microbiota dynamic face to biotic and abiotic parameters • Microbiota patterns as biomarkers in bivalve diseases
Education
October 2013 - September 2016
Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne (LUBEM, Université de Bretagne Occidentale)
Field of study
- Marine microbiology and biochemistry
September 2011 - September 2013
Institut Universitaire et Européen de la Mer (IEUM, Université de Bretagne Occidentale, Brest, France)
Field of study
- Biotechnological valorization of marine resources
September 2009 - September 2011
IUEM (Université de Bretagne Occidentale)
Field of study
- Biology of Organisms and Populations
Publications
Publications (19)
Digestive microbiota provides a wide range of beneficial effects on host physiology and are therefore likely to play a key role in marine intertidal bivalve ability to acclimatize to the intertidal zone. This study investigated the effect of intertidal levels on the digestive bacterial microbiota of oysters Crassostrea gigas and clams Ruditapes phi...
Three bacterial strains, named h Oe -66 T , h Oe -124 and h Oe -125, were isolated from the haemolymph of different specimens of the flat oyster Ostrea edulis collected in Concarneau bay (Finistère, France). These strains were characterized by a polyphasic approach, including (i) whole genome analyses with 16S rRNA gene sequence alignment and pange...
The Manila clam (Ruditapes philippinarum) is the second most exploited bivalve in the world but remains threatened by diseases and global changes. Their associated microbiota play a key role in their fitness and acclimation capacities. This study aimed at better understanding the behavior of clam digestive glands and extrapallial fluids microbiota...
Biomolecules offering health effects on inflammation, as cause or effect of metabolic syndrome, are the subject of many research studies. Among different classes of marine and terrestrial bioactive compounds, fish-extracted biopeptides are of great importance since they have been proven to modulate inflammation in different experimental settings. T...
Five strains of Pseudoalteromonas, isolated from oyster hemolymph, exhibited antibacterial activity against several Gram-negative bacteria. Bioactive compounds were identified in their cell-free supernatant and characterized as alterins, which are cyclolipopeptides composed of an heptapeptidic ring connected to a fatty acid chain. Using UPLC-HRMS,...
The Manila clam ( Ruditapes philippinarum) is the second most exploited bivalve in the world but remains threatened by diseases and global changes. Their associated microbiota play a key role in their fitness and acclimation capacities. This study aimed at better understanding the behavior of clam digestive glands and extrapallial fluids microbiota...
Due to a constant microbial pressure, marine animals harbor a specific microbiota that can be assimilated to a microbial shield. This hypothesis is supported by the hologenome theory of evolution. To explore the host associated bacteria and their metabolite chemodiversity we used marine bivalves as natural selectors.
As a first step, we defined the...
Egg yolk phosvitin is of particular interest due to its functional and biological properties. Recently, it was demonstrated that high hydrostatic pressure (HHP) (400 MPa for 5 min) induced the transfer of folic acid and phosvitin from the egg yolk granule to the plasma fraction. A granule fraction (Gin) produced by egg yolk centrifugation was press...
Snow crab (Chionoecetes opilio) by-products are a rich source of biomolecules, such as lipids, proteins, and chitin, which have not been extensively investigated. This study aims to identify antibacterial peptides to enhance the value of C. opilio by-products. After hydrolysis of different component parts using Protamex®, and concentration by solid...
The Atlantic mackerel, Scomber scombrus, is one of the most fished species in the world, but it is still largely used for low-value products, such as bait; mainly for crustacean fishery. This resource could be transformed into products of high value and may offer new opportunities for the discovery of bioactive molecules. Mackerel hydrolysate was i...
The hemolymph of healthy marine invertebrates is known to harbor antibiotic-producing bacteria belonging to the genus Pseudoalteromonas. Such strains are potential probiotics to control infectious diseases in aquaculture. In the present study, we screened a collection of Pseudoalteromonas strains isolated from the hemolymph of oyster and mussel for...
Aims: The aim of this study was to investigate the diversity of bacteria with antimicrobial activity present in the coelomic fluid and haemolymph of wild and healthy echinodermata and mollusca. Methods and Results: Collection expeditions of healthy marine molluscs and echinoderms were conducted in the Glenan archipelago in spring 2014. Members of t...
Food safety is a public health priority. Antimicrobial resistance has been posing increasingly serious concern to the public, health specialists and food industries. To overcome this threat and to retain consumer confidence in a safe and “clean label” food supply, searching for alternative natural antimicrobials is extensively investigated. The dev...
The diversity and function of the circulatory fluid microbiota of marine invertebrates are still unclear. This microbiota may exert a hurdle effect against potential pathogenic bacteria. In this context, the antimicrobial activity of bacteria composing the circulatory fluid microbiota of 4 marine invertebrates was explored. The coelomic fluid of th...
This review is dedicated to the antimicrobial metabolite-producing Pseudoalteromonas strains. The genus Pseudoalteromonas hosts 41 species, among which 16 are antimicrobial metabolite producers. To date, a total of 69 antimicrobial compounds belonging to 18 different families have been documented. They are classified into alkaloids, polyketides, an...
Exploration of abalone microbiota as microbial shielding against pathogens. After a short (4 hour-long) exposition to Pseudoalteromonas hCg-6, the strain was rapidly and significantly detected in the hemolymph of abalone exposed to Pseudoalteromonas sp. hCg-6 at 1·106. The short exposition to Pseudoalteromonas hCg-6 resulted in a significant decrea...
Wild or farmed abalone are regularly exposed to stressors, such as air exposure and handling. Immune and transcriptional responses as well as susceptibility to vibriosis of sexually mature or immature European abalone acclimated at 16 or 19°C were determined following handling or air exposure. Hemocyte density and H2O2 production increased while he...
L'étude du statut physiologique des organismes face à des conditions contraignantes permet de mieux comprendre leur tolérance à ces stress. Ces vingt dernières années, des recherches ont notamment été initiées sur l'effet des activités anthropiques sur l'immunité et la sensibilité des organismes marins face à des agents pathogènes. En écloserie et...
Projects
Projects (4)
Bivalves associated with coastal marine ecosystems are confronted with changes in their habitat and a resurgence of pathogens, which leads to high mortality. It is therefore necessary to understand which factors have an impact on their health and their ability to acclimatize. Among different factors, their digestive microbiota are likely to play a major role in their physiology and resistance to infections. The establishment and structuring of these microbiotas depends on the environment, the type of food ingested, the physiological, genetic and immune characteristics of the host, and the interactions between microorganisms. There is currently no understanding of the intertidal position effect on the structuration of bivalve microbiota, while their physiology, physical condition, and infection resistance are impacted. The main objective of this study will be to characterize the effect of intertidal level on the bacterial diversity of digestive microbiota of burrowing (Ruditapes philippinarum) or non-burrowing (Crassostera gigas) bivalves positioned at different levels on the same intertidal site (site BR08 in the Bay of Brest) using metabarcoding techniques. Physiological parameters and resistance to infections will also be studied, as well as environmental parameters (biotics and abiotics) in order to link the physiology of the host, the structuring of its digestive microbiota and its ability to withstand infection based on environmental parameters.
Etude fonctionnelle des peptides et protéines générés par hydrolyse enzymatique du maquereau dans la prévention des maladies infectieuses et inflammatoires
Evaluation of marine bacteria, Pseudoalteromonas hCg-6 as probiotic for halioticulture.
