Publications by authors named "Guillaume Nonglaton"

11 Publications

  • Page 1 of 1

Nitrilase immobilization and transposition from a micro-scale batch to a continuous process increase the nicotinic acid productivity.

Biotechnol J 2021 Jul 16:e2100010. Epub 2021 Jul 16.

CEA, LITEN, DTCH, Laboratoire Composants et Systèmes Thermiques (LCST), Univ. Grenoble Alpes, Grenoble, France.

In recent years, many biocatalytic processes have been developed for the production of chemicals and pharmaceuticals. In this context, enzyme immobilization methods have attracted attention for their advantages, such as continuous production and increased stability. Here, enzyme immobilization methods and a collection of nitrilases from biodiversity for the conversion of 3-cyanopyridine to nicotinic acid were screened. Substrate conversion over 10 conversion cycles was monitored to optimize the process. The best immobilization conditions were found with cross-linking using glutaraldehyde to modify the PMMA beads. This method showed good activity over 10 cycles in a batch reactor at 30 and 40°C. Finally, production with a new thermostable nitrilase was examined in a continuous packed bed reactor, showing very high stability of the biocatalytic process at a flow rate of 0.12 ml min and a temperature of 50°C. The complete conversion of 3-cyanopyridine was obtained over 30 days of operation. Future steps will concern reactor scale-up to increase the production rate with reasonable pressure drops.
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http://dx.doi.org/10.1002/biot.202100010DOI Listing
July 2021

Towards a passive limitation of particle surface contamination in the Columbus module (ISS) during the MATISS experiment of the Proxima Mission.

NPJ Microgravity 2020 20;6:29. Epub 2020 Oct 20.

Univ Lyon, ENS de Lyon, CNRS, Laboratoire de Physique, Lyon, France.

Future long-duration human spaceflight calls for developments to limit biocontamination of the surface habitats. The MATISS experiment tests surface treatments in the ISS's atmosphere. Four sample holders were mounted with glass lamella with hydrophobic coatings, and exposed in the Columbus module for ~6 months. About 7800 particles were detected by tile scanning optical microscopy (×3 and ×30 magnification) indicating a relatively clean environment (a few particles per mm), but leading to a significant coverage-rate (>2% in 20 years). Varied shapes were displayed in the coarse (50-1500 µm) and fine (0.5-50 µm) area fractions, consistent with scale dices (tissue or skin) and microbial cells, respectively. The 200-900 µm fraction of the coarse particles was systematically higher on FDTS and SiOCH than on Parylene, while the opposite was observed for the <10 µm fraction of the fine particles. This trend suggests two biocontamination sources and a surface deposition impacted by hydrophobic coatings.
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http://dx.doi.org/10.1038/s41526-020-00120-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7576818PMC
October 2020

Long duration stabilization of porous silicon membranes in physiological media: Application for implantable reactors.

Mater Sci Eng C Mater Biol Appl 2020 Mar 2;108:110359. Epub 2019 Nov 2.

Université Grenoble Alpes / CNRS / TIMC-IMAG UMR 5525 (SyNaBi), Grenoble, France, Faculté de Médecine, 38706, La Tronche cedex, France. Electronic address:

The natural biodegradabilty of porous silicon (pSi) in physiological media limits its wider usage for implantable systems. We report the stabilization of porous silicon (pSi) membranes by chemical surface oxidation using RCA1 and RCA2 protocols, which was followed by a PEGylation process using a silane-PEG. These surface modifications stabilized the pSi to allow a long period of immersion in PBS, while leaving the pSi surface sufficiently hydrophilic for good filtration and diffusion of several biomolecules of different sizes without any blockage of the pSi structure. The pore sizes of the pSi membranes were between 5 and 20 nm, with the membrane thickness around 70 μm. The diffusion coefficient for fluorescein through the membrane was 2 × 10 cm s, and for glucose was 2.2 × 10 cm s. The pSi membrane maintained that level of glucose diffusion for one month of immersion in PBS. After 2 months immersion in PBS the pSi membrane continued to operate, but with a reduced glucose diffusion coefficient. The chemical stabilization of pSi membranes provided almost 1 week stable and functional biomolecule transport in blood plasma and opens the possibility for its short-term implantation as a diffusion membrane in biocompatible systems.
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http://dx.doi.org/10.1016/j.msec.2019.110359DOI Listing
March 2020

Highly absorbent cellulose nanofibrils aerogels prepared by supercritical drying.

Carbohydr Polym 2020 Feb 4;229:115560. Epub 2019 Nov 4.

Univ. Grenoble Alpes, CNRS, CERMAV, 38000 Grenoble, France.

In this paper, strictly speaking aerogels of cellulose nanofibrils (CNFs) and TEMPO-oxidized CNFs (TO-CNFs) were obtained from an optimized supercritical drying processes and cryogels were prepared after freeze-drying. The cryogels and aerogels were characterized and the influence of the preparation process on the resulting properties was studied. Significant differences were observed in the micro- and nanoscale organization of the porous structures. In addition, the specific surface areas measured varied from 25 to 160 m² g for CNF materials, depending on the preparation process. Very high specific surface areas up to 482 m² g among the highest reported for pure cellulose nanofibrils porous materials were achieved for TO-CNF aerogels. Finally, in order to evaluate their aptitudes for wound dressings applications, the capillary water uptake capacities were assessed on skin mimicking layers. From this study, it was revealed that TO-CNF aerogels can absorb almost 120 times their own weight of water.
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http://dx.doi.org/10.1016/j.carbpol.2019.115560DOI Listing
February 2020

A robust ALD-protected silicon-based hybrid photoelectrode for hydrogen evolution under aqueous conditions.

Chem Sci 2019 Apr 12;10(16):4469-4475. Epub 2019 Mar 12.

Université Grenoble Alpes , CNRS , CEA , Laboratoire de Chimie et Biologie des Métaux , 17 rue des Martyrs , 38000 Grenoble , France . Email:

Hydrogen production through direct sunlight-driven water splitting in photo-electrochemical cells (PECs) is a promising solution for energy sourcing. PECs need to fulfill three criteria: sustainability, cost-effectiveness and stability. Here we report an efficient and stable photocathode platform for H evolution based on Earth-abundant elements. A p-type silicon surface was protected by atomic layer deposition (ALD) with a 15 nm TiO layer, on top of which a 300 nm mesoporous TiO layer was spin-coated. The cobalt diimine-dioxime molecular catalyst was covalently grafted onto TiO through phosphonate anchors and an additional 0.2 nm ALD-TiO layer was applied for stabilization. This assembly catalyzes water reduction into H in phosphate buffer (pH 7) with an onset potential of +0.47 V RHE. The resulting current density is -1.3 ± 0.1 mA cm at 0 V RHE under AM 1.5 solar irradiation, corresponding to a turnover number of 260 per hour of operation and a turnover frequency of 0.071 s.
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http://dx.doi.org/10.1039/c8sc05006fDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6482884PMC
April 2019

Metallic Conductive Nanowires Elaborated by PVD Metal Deposition on Suspended DNA Bundles.

Small 2017 09 5;13(33). Epub 2017 Jul 5.

Université Grenoble Alpes, F-38000, Grenoble, France.

Metallic conductive nanowires (NWs) with DNA bundle core are achieved, thanks to an original process relying on double-stranded DNA alignment and physical vapor deposition (PVD) metallization steps involving a silicon substrate. First, bundles of DNA are suspended with a repeatable process between 2 µm high parallel electrodes with separating gaps ranging from 800 nm to 2 µm. The process consists in the drop deposition of a DNA lambda-phage solution on the electrodes followed by a naturally evaporation step. The deposition process is controlled by the DNA concentration within the buffer solution, the drop volume, and the electrode hydrophobicity. The suspended bundles are finally metallized with various thicknesses of titanium and gold by a PVD e-beam evaporation process. The achieved NWs have a width ranging from a few nanometers up to 100 nm. The electrical behavior of the achieved 60 and 80 nm width metallic NWs is shown to be Ohmic and their intrinsic resistance is estimated according to different geometrical models of the NW section area. For the 80 nm width NWs, a resistance of about few ohms is established, opening exploration fields for applications in microelectronics.
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http://dx.doi.org/10.1002/smll.201700956DOI Listing
September 2017

A DNA array based on clickable lesion-containing hairpin probes for multiplexed detection of base excision repair activities.

Analyst 2016 Oct;141(22):6208-6216

Université Grenoble Alpes, INAC - SyMMES/CEA, 17 rue des martyrs, F-38000 Grenoble, France.

DNA is under continuous assault by environmental and endogenous reactive oxygen and alkylating species, inducing the formation of mutagenic, toxic and genome destabilizing nucleobase lesions. Due to the implications of such genetic alterations in cell death, aging, inflammation, neurodegenerative diseases and cancer, many efforts have been devoted to developing assays that aim at analyzing DNA repair activities from purified enzymes or cell extracts. The present work deals with the conception and application of a new, miniaturized and parallelized on surface-DNA biosensor to measure base excision repair (BER) activities. Such a bio-analytical tool was built by using the "click chemistry" approach to immobilize, on a glass slide, fluorescent stem-loop DNA probes, which contain a specific nucleobase lesion. The performance of this new high-throughput DNA repair analysis technology was determined by detecting uracil N-glycosylase and AP-endonuclease activities from purified enzymes or in cell extracts. The applications of this device were extended to analyze, in cell extracts, the ability of two inhibitors (Uracil glycosylase inhibitor (Ugi) and methoxyamine (MX)) to block the excision of uracil and the cleavage of AP sites, respectively. Altogether, our results show that this new fluorescent DNA microarray platform provides an easy, rapid and robust method for detecting DNA N-glycosylase and AP-endonuclease activities and evaluating the effects of BER inhibitors in a multiplexed fashion.
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http://dx.doi.org/10.1039/c6an01165aDOI Listing
October 2016

Selective detection of bacterial layers with terahertz plasmonic antennas.

Biomed Opt Express 2012 Nov 23;3(11):2937-49. Epub 2012 Oct 23.

FOM Institute AMOLF, Centre for Nanophotonics, c/o Philips Research Laboratories, HTC4, 5656AE Eindhoven, The Netherlands . ; Now with Universität Stuttgart, 1.Physikalisches Institut, Pffafenwaldring 57, 70550 Stuttgart, Germany.

Current detection and identification of micro-organisms is based on either rather unspecific rapid microscopy or on more accurate but complex and time-consuming procedures. In a medical context, the determination of the bacteria Gram type is of significant interest. The diagnostic of microbial infection often requires the identification of the microbiological agent responsible for the infection, or at least the identification of its family (Gram type), in a matter of minutes. In this work, we propose to use terahertz frequency range antennas for the enhanced selective detection of bacteria types. Several microorganisms are investigated by terahertz time-domain spectroscopy: a fast, contactless and damage-free investigation method to gain information on the presence and the nature of the microorganisms. We demonstrate that plasmonic antennas enhance the detection sensitivity for bacterial layers and allow the selective recognition of the Gram type of the bacteria.
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http://dx.doi.org/10.1364/BOE.3.002937DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3493226PMC
November 2012

Metal phosphonates applied to biotechnologies: a novel approach to oligonucleotide microarrays.

Chemistry 2005 Mar;11(7):1980-8

Laboratoire de Synthèse Organique, UMR CNRS 6513 & FR CNRS 2465, 2 Rue de la Houssinière, BP92208, 44322 Nantes Cedex 03, France.

A new process for preparing oligonucleotide arrays is described that uses surface grafting chemistry which is fundamentally different from the electrostatic adsorption and organic covalent binding methods normally employed. Solid supports are modified with a mixed organic/inorganic zirconium phosphonate monolayer film providing a stable, well-defined interface. Oligonucleotide probes terminated with phosphate are spotted directly on to the zirconated surface forming a covalent linkage. Specific binding of terminal phosphate groups with minimal binding of the internal phosphate diesters has been demonstrated. The mixed organic/inorganic thin films have also been extended for use arraying DNA duplex probes, and therefore represent a viable general approach to DNA-based bioarrays. Ideas for interfacing mixed organic/inorganic interfaces to other bioapplications are also discussed.
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http://dx.doi.org/10.1002/chem.200400960DOI Listing
March 2005

New approach to oligonucleotide microarrays using zirconium phosphonate-modified surfaces.

J Am Chem Soc 2004 Feb;126(5):1497-502

Laboratoire de Synthèse Organique, UMR CNRS 6513 and FR CNRS 2465, 2 Rue de la Houssinière, BP92208, 44322 Nantes Cedex 03, France.

A new approach to oligonucleotide arrays is demonstrated that utilizes zirconium phosphonate-derivatized glass slides. The active slides are prepared by binding Zr(4+) to surfaces terminated with organophosphonate groups previously deposited using either Langmuir-Blodgett or self-assembled monolayer methods. Oligonucleotide probes modified with a terminal phosphate bind strongly to the active zirconium phosphonate monolayer, and arrays for detecting fluorescent targets have been prepared using commercial spotting and scanning instruments. Preferred binding to the surface of the terminal phosphate of the modified probes instead of the internal phosphate diester groups is demonstrated and shown to yield increased fluorescence intensity after hybridization with labeled targets. A significant decrease in background signal is achieved by treating the slides with bovine serum albumin after spotting and before hybridization. A further increase in fluorescence after hybridization is observed when using a poly-guanine spacer between the probe oligomer and the terminal phosphate. Combining these modifications, an intensity ratio of nearly 1000 is achieved when comparing 5'-phosphate-modified 33-mer probes with unmodified probes upon hybridization with fluorescent targets.
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http://dx.doi.org/10.1021/ja039072rDOI Listing
February 2004
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