References of "Martin, Marjolaine"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailIdentification and Characterization of a Halotolerant, Cold-Active Marine Endo-β-1,4-Glucanase by Using Functional Metagenomics of Seaweed-Associated Microbiota
Martin, Marjolaine ULg; Biver, Sophie ULg; Steels, Sébastien ULg et al

in Applied and Environmental Microbiology (2014), 80(16), 4958-4967

A metagenomic library was constructed from microorganisms associated with the brown alga Ascophyllum nodosum. Functional screening of this library revealed 13 novel putative esterase loci and two ... [more ▼]

A metagenomic library was constructed from microorganisms associated with the brown alga Ascophyllum nodosum. Functional screening of this library revealed 13 novel putative esterase loci and two glycoside hydrolase loci. Sequence and gene cluster analysis showed the wide diversity of the identified enzymes and gave an idea of the microbial populations present during the sample collection period. Lastly, an endo-β-1,4-glucanase having less than 50% identity to sequences of known cellulases was purified and partially characterized, showing activity at low temperature and after prolonged incubation in concentrated salt solutions. [less ▲]

Detailed reference viewed: 18 (0 ULg)
Full Text
Peer Reviewed
See detailMicroorganisms living on macroalgae: diversity, interactions, and biotechnological applications
Martin, Marjolaine ULg; Portetelle, Daniel ULg; Michel, Gurvan et al

in Applied Microbiology & Biotechnology (2014)

Marine microorganisms play key roles in every marine ecological process, hence the growing interest in studying their populations and functions. Microbial communities on algae remain underexplored ... [more ▼]

Marine microorganisms play key roles in every marine ecological process, hence the growing interest in studying their populations and functions. Microbial communities on algae remain underexplored, however, despite their huge biodiversity and the fact that they differ markedly from those living freely in seawater. The study of this microbiota and of its relationships with algal hosts should provide crucial information for ecological investigations on algae and aquatic ecosystems. Furthermore, because these microorganisms interact with algae in multiple, complex ways, they constitute an interesting source of novel bioactive compounds with biotechnological potential, such as dehalogenases, antimicrobials, and alga-specific polysaccharidases (e.g., agarases, carrageenases, and alginate lyases). Here, to demonstrate the huge potential of alga-associated organisms and their metabolites in developing future biotechnological applications, we first describe the immense diversity and density of these microbial biofilms. We further describe their complex interactions with algae, leading to the production of specific bioactive compounds and hydrolytic enzymes of biotechnological interest. We end with a glance at their potential use in medical and industrial applications. [less ▲]

Detailed reference viewed: 29 (13 ULg)
Full Text
Peer Reviewed
See detailBiomass hydrolyzing enzymes identified by functional screening of a metagenomic library from algal biofilms.
Martin, Marjolaine ULg; Biver, Sophie ULg; Barbeyron, Tristan et al

Poster (2013, June)

Biomass hydrolyzing enzymes are increasingly searched for the production of biofuels and renewable chemical compounds using biomass. Microorganisms living on algaes are an interesting reservoir of biomass ... [more ▼]

Biomass hydrolyzing enzymes are increasingly searched for the production of biofuels and renewable chemical compounds using biomass. Microorganisms living on algaes are an interesting reservoir of biomass hydrolyzing enzymes, as they are in constant interaction with algal biomass. Therefore, we are interested in looking for some of those enzymes synthesized by the microflora living on the surface of the brown algae Ascophyllum nodosum. Algae samples were collected in the winter 2012 and a microbial DNA extraction method was developed. The whole extracted microbial genomes of the microorganisms living on the algae were restricted, inserted in a cloning vector and ligated products were used for transformation of cultivable Escherichia coli host cells. This metagenomic library was then screened for diverse enzymatic activities (lipolytic enzymes, cellulases, beta-glucosidases, alpha-amylases, arabinanases, xylanases and proteases) on agar plates with specific substrates. Five putative lipolytic enzymes, one cellulase and one beta-glucosidase were identified. Sequence analysis revealed low (<50%) sequence identities with known enzymes sequences, meaning new enzymes from unknown genomes have been discovered. To our knowledge this is the first functional screening that was realized with a metagenomic library from algal biofilms and this is the first cellulase identified by marine metagenomics. A second library has been constructed from algae sample from summer 2012 and is currently being screened. New enzymatic tests are being developed for the identification of enzymes degrading specific algal polysaccharides like agarases, carrageenases, alginate lyases, laminarinases,… Those very specific enzymes aren’t well known yet, and our metagenomic approach will probably help us to identify new families and structures of those algal biomass hydrolyzing enzymes. [less ▲]

Detailed reference viewed: 176 (19 ULg)
Full Text
See detailMicroorganisms living on algae : An interesting reservoir of enzymes hydrolyzing algal biomass
Martin, Marjolaine ULg; Biver, Sophie ULg; Barbeyron, Tristan et al

Poster (2013, April 18)

Algal polysaccharides are increasingly used in food industry for their gelling properties and in pharmacology for their therapeutic properties. Furthermore, increasingly interest is taken on algae for ... [more ▼]

Algal polysaccharides are increasingly used in food industry for their gelling properties and in pharmacology for their therapeutic properties. Furthermore, increasingly interest is taken on algae for their use in the production of biofuels and bioenergies. To purify algal polysaccharides and degrade algal biomass, specific microbial enzymes are needed. Microorganisms living on algae are an interesting source of those enzymes, as they are in constant interaction with algal biomass. The aim of our study is to identify new enzymes degrading algae, produced by microorganisms living on the surface of algae. Therefore we developed a method for microbial DNA extraction from biofilms living on brown algae (Ascophyllum nodosum). Microbial DNA was extracted, restricted and inserted in cultivable host cells of Echerichia coli, for the construction of our metagenomic DNA library. This metagenomic library was first screened, on solid media with specific substrates, for enzymes generally used in the degradation of biomass (lipases, cellulases, proteases, beta-glucosidases, alpha-amylases, arabinanases and xylanases). Five lipolytic enzymes, one beta-glucosidase and one cellulase were identified. Those enzymes show very low percentages of sequences identities with known enzymes, meaning we identified new and unknown enzymes. Those enzymes and their activity are being characterized. Preliminary tests show interesting results, like a cellulase active at low temperature. Screening tests are now being developed to identify enzymes hydrolyzing algal polysaccharides like agarases, carrageenases, alginate lyases, laminarinases,… Those enzymes aren’t well known yet and we hope to identify new enzymes (families) with our rich DNA library by our approach. [less ▲]

Detailed reference viewed: 14 (2 ULg)
Full Text
See detailFunctional screening of a metagenomic library from algal biofilms
Martin, Marjolaine ULg

Conference (2013, February 08)

Macroalgae, and particularly their lignin-free polysaccharides, are increasingly used for their gelling and therapeutic properties and for the production of biofuels and renewable chemical compounds. To ... [more ▼]

Macroalgae, and particularly their lignin-free polysaccharides, are increasingly used for their gelling and therapeutic properties and for the production of biofuels and renewable chemical compounds. To extract, hydrolyze and purify this biomass, algae hydrolyzing enzymes are needed. Our work aims to identify and characterize algal biomass hydrolyzing enzymes expressed by microorganisms living on the surface of algae, by functional metagenomics. Therefore, a microbial DNA extraction method was developed to isolate the gDNA from the microorganisms of the brown algae Ascophyllum nodosum and a metagenomic library was constructed in Escherichia coli. The library was screened for diverse enzymatic activities (esterases, xylanases, cellulases, α-amylases, arabinanases, caseinases and β-glucosidases) on agar plates with specific enzymes substrates. Several new microbial enzymes (esterases, β-glucosidases, α-amylases and cellulases) were identified revealing the wealth of our library. Furthermore, those enzymes had less than 50% sequence identity with known protein sequences; meaning that our approach allows to identify new microbial enzymes expressed by uncultured microorganisms. Plate tests for medium-throughput screening of specific enzymes hydrolyzing algal polysaccharides (agarases, carrageenases and alginate lyases) are currently being developed. Our approach will probably allow us to identify new families of those ill-known enzymes, with particular enzymatic activities. [less ▲]

Detailed reference viewed: 149 (19 ULg)
Full Text
Peer Reviewed
See detailFunctional screening of a metagenomic library from algal biofilms
Martin, Marjolaine ULg; Barbeyron, Tristan; Michel, Gurvan et al

in Smagghe, Guy; Boeckx, Pascal; Bossier, Peter (Eds.) et al Communications in Agricultural and Applied Biological Sciences (2013, February 08)

Macroalgae, and particularly their lignin-free polysaccharides, are increasingly used for their gelling and therapeutic properties and for the production of biofuels and renewable chemical compounds. To ... [more ▼]

Macroalgae, and particularly their lignin-free polysaccharides, are increasingly used for their gelling and therapeutic properties and for the production of biofuels and renewable chemical compounds. To extract, hydrolyze and purify this biomass, algae hydrolyzing enzymes are needed. Our work aims to identify and characterize algal biomass hydrolyzing enzymes expressed by microorganisms living on the surface of algae, by functional metagenomics. Therefore, a microbial DNA extraction method was developed to isolate the gDNA from the microorganisms of the brown algae Ascophyllum nodosum and a metagenomic library was constructed in Escherichia coli. The library was screened for diverse enzymatic activities (esterases, xylanases, cellulases, α-amylases, arabinanases, caseinases and β-glucosidases) on agar plates with specific enzymes substrates. Several new microbial enzymes (esterases, β-glucosidases, α-amylases and cellulases) were identified revealing the wealth of our library. Furthermore, those enzymes had less than 50% sequence identity with known protein sequences; meaning that our approach allows to identify new microbial enzymes expressed by uncultured microorganisms. Plate tests for medium-throughput screening of specific enzymes hydrolyzing algal polysaccharides (agarases, carrageenases and alginate lyases) are currently being developed. Our approach will probably allow us to identify new families of those ill-known enzymes, with particular enzymatic activities. [less ▲]

Detailed reference viewed: 122 (18 ULg)
Full Text
Peer Reviewed
See detailIdentification of new microbial enzymes from forest and marine ecosystems by functional metagenomics
Martin, Marjolaine ULg; Biver, Sophie ULg; Barbeyron, Tristan et al

Poster (2012, August 21)

Detailed reference viewed: 89 (36 ULg)
Full Text
See detailImplémentation d'une méthode de détection du virus de la diarrhée virale bovine au sein de la fondation de la promotion des productions andines Proinpa (Bolivie)
Martin, Marjolaine ULg

Master's dissertation (2010)

An animal infected by the Bovine Viral Diarrhea Virus will have diarrheas, which can lead to milk production reduction, reproduction problems (and particularly abortion problems) and general weakness ... [more ▼]

An animal infected by the Bovine Viral Diarrhea Virus will have diarrheas, which can lead to milk production reduction, reproduction problems (and particularly abortion problems) and general weakness. This all leads to an economic loss. This is why the virus detection and the carriers, or Persistently Infected (PI) animals, eradication are important. If the virus presence was previously suspected in Bolivia, since 2009 it is certain that there is BVDV infection and the prevalence is high in comparison with others areas. Furthermore, this virus can also infect « New Worlds camelids » which are the alpacas, lamas, vicunas and guanacos species living in South-America. The aim of this study was to implement a BVDV detection method for the Foundation of Andeans Productions Promotion PROINPA in Bolivia. This objective was first met by a prevalence evaluation of the virus using ELISA anti-antibodies analysis. Then, a screening of the tested herds containing animals with a positive serology was done by real-time PCR and finally the PI animals were detected by individual real-time PCR analysis or by two ELISA anti-antigens analysis’s in a 3 week's interval. There was no problem from an infrastructure viewpoint; the laboratories have all the necessary material and equipment and the labor was qualified for both analyses. But the logistic part was more difficult, because the molecular kit has to be preserved at minus twenty degrees. And this kit took 10 days to arrive from Belgium. Because none of the molecular analysis’s succeeded, we concluded that the kit had been damaged during the travel and had been degraded. The kit conservation conditions seemed to be a problem and that is why the elaboration of a new lyophilized kit was tried in Belgium. The lyophilisation of the BVDV sequences, the IPC and EPC was easy but wasn’t possible for the Master MIX (containing the Taq Polymerase (Taq)) and the Reverse Transcriptase (RT). The « Illustra Ready-To-GoTM RT-PCR Beads », from GE Healthcare, are beads made of Taq and RT that can be stored at room temperature. The combination of a lyophilized part of the LSI kit (BVDV sequences, EPC and IPC) with those beads will lead to a molecular BVDV detection kit that can be stored at room temperature. However, this combination doesn’t seem to work. This can be due to a lot of different things like the incompatibility between the primers size and design and the Taq, the temperature activities of the Taq and the RT, the salt concentration, etc. In conclusion, different experiments are required to finalize a qPCR kit resistant to long trip conditions. [less ▲]

Detailed reference viewed: 35 (11 ULg)