Diversity in Biorefinery : an interdisciplinary approachon Science, Business and "doubly green" Chemistry

International audienceThe word “biorefinery” was coined to describe an industrial process of cracking biomass resembling the industrial cracking of fossil carbon (Kamm and Kamm, 2005). But it can also be seen as an "Intermediary Object" (Vinck 2009) socially constructed by macroactors in European projects such as "Star-Colibri", with a view to developing a particular vision of the transition towards the use of renewable resources. Narrative approaches are mobilized by sociologists to describe the complexity of systemic change in a multilevel perspective (Grin, Rotmans and Schot, 2010). Narratives have also been used in Economics and Management of Technologies since the works of David (1985) to Dumez and Jeunemaitre (2005), to identify and describe various potential technological trajectories. We used a similar (analysis, cognitive process, method, procedure.) in the course of an interdisciplinary approach involving economists chemists and biochemists. Our "narrative approach" aims at highlighting the diversity of technological expectations. In the dominant vision of the biorefinery, large-scale units crack the biomass into a limited number (top 10 chemical intermediates) of standardized "small molecules", easily purified and introduced into the traditional petrochemical processes. Production of liquid fuels ("bio"-fuels) would enable economic operators to reach this large scale, while chemicals with high added value should ensure their economic balance (Bozell, Petersen 2010). However, other technical routes are worth considering: For example the intrinsic complexity and self-organization properties of biomass materials can be used as a way to introducing principles of green chemistry in processes operating more systematically on the macromolecular level ("one pot", whole plant, "reactive extrusion", modified starches, photochemistry and so on ..). They minimize fractionation steps and thus the use of energy or water. They can also entail smaller scale chemical units, which would not need to be stitched to the existing network of large-scale commodities production (of "bio"fuels,) and would be better rooted in local production areas. The discussion on the transition must therefore integrate the diversity of possible technical (ways) (routes) and examine how institutional policies support either of these solutions

Neural Network Parameterizations of Electromagnetic Nucleon Form Factors

The electromagnetic nucleon form-factors data are studied with artificial feed forward neural networks. As a result the unbiased model-independent form-factor parametrizations are evaluated together with uncertainties. The Bayesian approach for the neural networks is adapted for chi2 error-like function and applied to the data analysis. The sequence of the feed forward neural networks with one hidden layer of units is considered. The given neural network represents a particular form-factor parametrization. The so-called evidence (the measure of how much the data favor given statistical model) is computed with the Bayesian framework and it is used to determine the best form factor parametrization.Comment: The revised version is divided into 4 sections. The discussion of the prior assumptions is added. The manuscript contains 4 new figures and 2 new tables (32 pages, 15 figures, 2 tables

Silver activation on thin films of Ag-ZrCN coatings for antimicrobial activity

Nowadays, with the increase of elderly population and related health problems, knee and hip joint prosthesis are being widely used worldwide. However, failure of these invasive devices occurs in a high percentage thus demanding the revision of the chirurgical procedure. Within the reasons of failure, microbial infections, either hospital or subsequently-acquired, contribute in high number to the statistics. Staphylococcus epidermidis (S. epidermidis) has emerged as one of the major nosocomial pathogens associated with these infections. Silver has a historic performance in medicine due to its potent antimicrobial activity, with a broad-spectrum on the activity of different types of microorganisms. Consequently, the main goal of this work was to produce Ag-ZrCN coatings with antimicrobial activity, for the surface modification of hip prostheses. Thin films of ZrCN with several silver concentrations were deposited onto stainless steel 316 L, by DC reactive magnetron sputtering, using two targets, Zr and Zr with silver pellets (Zr + Ag target), in an atmosphere containing Ar, C2H2 and N2. The antimicrobial activity of the modified surfaces was tested against S. epidermidis and the influence of an activation step of silver was assessed by testing samples after immersion in a 5 % (w/v) NaClO solution for 5 minutes. The activation procedure revealed to be essential for the antimicrobial activity, as observed by the presence of an inhibition halo on the surface with 11 at. % of Ag. The morphology analysis of the surface before and after the activation procedure revealed differences in silver distribution indicating segregation/diffusion of the metallic element to the films surface. Thus, the results indicate that the silver activation step is responsible for an antimicrobial effect of the coatings, due to silver oxidation and silver ion release.IF acknowledges the financial support of FCT-Fundacao para a Ciencia e a Tecnologia through grant SFRH/BD/71139/2010.This research is partially sponsored by FEDER funds through the program COMPETE-Programa Operacional Factores de Competitividade and by Portuguese national funds through FCT-Fundacao para a Ciencia e a Tecnologia, under the projects ANTIMICROBCOAT-PTDC/CTM/102853/2008 and in the framework of the Strategic Projects PEST-C/FIS/UI607/2011, and PEST-C/EME/UI0285/2011.The authors thank the FCT Strategic Project PEST-OE/EQB/LA0023/2013 and the Project "BioHealth-Biotechnology and Bioengineering approaches to improve health quality", Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER. The authors also acknowledge the project "Consolidating Research Expertise and Resources on Cellular and Molecular Biotechnology at CEB/IBB", Ref. FCOMP-01-0124-FEDER-027462

Potential applications of fungal peroxidases in the biological processing of wood, lignocelluloses and related compounds

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Etude de la degradation de lignines macromoleculaires par la lignine peroxydase de P. chrysosporium

SIGLEINIST T 74099 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

La peroxydase de raifort est elle une enzyme ligninolytique?

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Dispersion of lignin in water : characterization of the phenomenon and influence on lignin enzymic degradability

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Influence of the physical state of lignin on its degradability by the lignin peroxydase of Phanerochaete chrysosporium

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Influence of lignin peroxidase concentration and localisation in lignin biodegradation by Phanerochaete chrysosporium

International audienceThe lignin mineralization rate in cultures of Phanerochaete chrysosporium increases with lignin peroxidase concentration up to 20 nkat ml–1. At higher concentrations the rate of lignin mineralization decreases with increasing lignin peroxidase concentration. The amount of mycelium is not a limiting factor for lignin mineralization at high exocellular lignin peroxidase in association with the mycelium as pellets and no free exocellular enzyme induce a lignin mineralization rate equivalent to cultures reconstituted with washed pellets supplemented with 15 nkat ml–1 of exogenous free enzyme. These results show that although lignin degradation by lignin peroxidase seems to be facilitated when lignin peroxidase is localised on the surface of the mycelium, free exocellular lignin peroxidase can also efficiently enhance mineralization of lignin by P. chrysosporium

Mapping twenty years of Green Chem: Four Productive Heritages moving towards "Doubly Green Chemistry" DGC Beyond the green varnish"

International audienceThe last twenty years have seen a tremendous turmoil in Green Chem Research and Economic developments. With the perspective of peak oil and CO2 taxation, the part of Green Chem publications dedicated to the use of rene wable resources in the last decade has become prevalent. But chemistry of renewable product can be very unsustainable, hence the emerging need of “Doubly Green Chemistry” (DGC) biosourced and sustainable concept. The scientific programs dedicated to the use of biomass seek to integrate other principles of green chemistry in addition to the seventh principle. The results exposed in the present paper were produced within an interdisciplinary research program, between economists, chemists and biochemists. Ou r aim consist in studying how scientific research programs, devoted to to using renewable resources, integrate the economic and technological dimensions of sustainable transitions in their conceptions and evolutions. Our results shows that the investment of the Green Chem. Community is based on institutionally built "visions to the future", these visions resulting from "technological roadmap"exercises. There is no unified vision of what DGC should be, but instead four distinct communities canbe observed in the field of green chemistry,. These communities are based on four distinct technological and productive heritages: PH1 Extensive thermal/catalytic deconstruction to C 1 C 5 molecules (eg; Thermo chemical transformation of biomass into syngas and refo rming.); PH2 Extensive biotechnological deconstruction to C 2 C 10 (Enzymatic transformation of biomass into small building blocks (for uses such as chemo synthetic PLA PHA). PH3 Limited chemical tailoring of extracted C 5 C 60 molecules (Use of natural ly occurring synthons (e.g. modified fatty acids for polymers); PH4 Limited deconstruction and transformations of biopolymers C x C n (Use of plant components and intricate polymolecular complexity trough innovative technologies (e.g. starch/hemicellulose /lignin/protein modif., using reactive extrusion, microwave, whole plant process) The internal logics of DGC integration by these different communities are analyzed in a supply chain analytical framework