Programme JDD 2014

Journée de l’Ecole Doctorale
Sciences des Procédés-Sciences des Aliments
Mardi 24 Juin 2014
AMPHITHEATRE 206
CAMPUS SUPAGRO-INRA, 2 PLACE PIERRE VIALA
34060 MONTPELLIER
Ecole Doctorale
Sciences des Procédés-Sciences des Aliments
11h10-11h30
Sarah Bellini, ITAP
Multispectral Optics in complex media: theory and application to
the monitoring of microalgal culture in a context of mass
production
Accueil des participants Accrochage des posters :
Hall d’honneur
11h30-11h50
Nakry Pen, IEM
An innovative membrane bioreactor for methane biohydroxylation
Présentation de la future Ecole Dotorale GAIA :
Marc Bouvy et Valérie Micard
11h50-14h00
Posters et repas : Buffet dans le parc de SupAgro
14h00-15h15
Table ronde : « Docteur-entrepreneur : rechercher pour
innover et entreprendre »
Pascal Peny, chargé de valorisation Montpellier SupAgro,
responsable de l’incubateur d’entreprises innovantes
Clément Arnal, docteur en géographie, entrepreneur porteur du
projet Via Terra
15h15-15h45
Pause café
15h45-17h00
Table ronde : « Le devenir du jeune chercheur, tour d’horizon
des modalités de recrutement »
Emna Chichti, Maitre de Conférences, IRC
Nicolas Hengl, Maitre de Conférences, Université de Grenobles
Mathieu Muller, Recherche et Développement,Envolure
Catherine Faur, Professeur, UM2
Valérie Micard, Professeur, SupAgro
Caroline Strub, Maitre de Conférences, Polytech Montpellier
Jean-Philippe Delgenès, Directeur de Recherche, INRA
17h00-17h15
Attribution des prix « meilleure communication orale » et meilleur
poster »
PROGRAMME
8h30-9h00
9h00-9h20
9h20-11h50
Présentations orales :
9h20-9h40
Stéphanie Rollero, SPO
Prediction of the effects of environmental factors
on the synthesis of fermentative aromas
9h40-10h00
Thibaut Saur, LBE
Impact of hydrodynamic conditions on structure of biofilms
10h00-10h20
10h20-10h50
10h50-11h10
Violette Bourg, C2MA
Influence of molecular architecture and processing conditions on
shrinkage behavior of biopolyester cast-film for packaging
applications
Pause café
Lizeth Lopez, IATE
Biochemical and Structural Characterization of two Acacia gum
species: Acacia Senegal and Acacia Seyal
Communications orales
Thibaut Saur
Laboratoire de Biotechnologie de l’Environnement
Impact of hydrodynamic conditions on structure of biofilms
Stéphanie Rollero
Sciences Pour l’œnologie
Prediction of the effects of environmental factors on the synthesis of
fermentative aromas
Most volatile compounds of organoleptic interest for young and
white wines are synthesized by yeast metabolism. Their production depends
both on yeast strain and on fermentation conditions. The objective of this
work was to study the combined effects of temperature, initial assimilable
nitrogen and lipid contents on the production of fermentative aromas.
Fermentations were performed using Lalvin EC1118® strain and thirty
compounds (higher alcohols, acids, ethyl and acetate esters) were measured
by GC-MS.
To identify the most discriminating factors in the production of each
flavor compound and possible interactions between those factors,
experiments were carried out according to a Box-Behnken matrix. This
experimental design limits the number of experiments while allowing the
calculation of the response surface for each studied parameter and therefore
estimating the conditions leading to a maximum (or minimum) production
of volatile compounds.
In addition, the “weight” of each environmental factor was
calculated. We found that nitrogen had the greatest impact on a large
number of flavor compounds, but the synthesis of several compounds (ethyl
esters) was also highly influenced by the lipid content and temperature.
Two kinds of biofilms are distinguished. Detrimental biofilms are
biofilms one wants to prevent or remove. They are encountered in industries
(food-processing, water supply…) and medical environments. They can
cause drastic economic losses or sanitary and health problems. On the other
hand, biofilms can be a valuable tool and optimizing these microbiological
systems can be useful. Biofilms are for example used for wastewater
treatment or energy production.
My work focuses on the impact of hydrodynamic conditions on
biofilms. I study both microbial adhesion – first step of biofilm formation –
and maturation of biofilm. A better understanding of the impact of shear on
these two steps is crucial to either prevent detrimental biofilm formation or
in contrary develop a beneficial biofilm system.
Hydrodynamic conditions can have paradoxical and complicated
effects on adhesion. On the one hand, improving mixing and fluid velocity
in the liquid phase enhances access of bacteria to the substratum. On the
other hand, shear also increases promoting detachment forces. The novelty
of this work consists of determining the impact of shear stress on microbial
adhesion for mixed culture in a turbulent flow which is more relevant for
bioprocess engineering.
Hydrodynamic conditions are also key parameter acting on
maturation of biofilms. It is commonly assumed that hydrodynamic
conditions shape biofilm morphology by inducing sloughing events, erosion
or compression Biofilm community structure can also directly or indirectly
be influenced by hydrodynamics conditions. If the literature focuses on
impact of the shear during the growth, my work deals with the impact of
drastic change in the environmental conditions (here hydrodynamics) on
mature biofilms. This better mimics industrial processes.
For both steps of biofilm life – adhesion and maturation – I studied
the morphological structure (spatial distribution of bacterial biomass) and
the microbiological structure (evolution of bacterial community)
Violette Bourg
Centre des Matériaux des Mines d’Alès
Influence of molecular architecture and processing conditions on
shrinkage behavior of biopolyester cast-film for packaging
applications
Introduction
In 2012, the packaging area has represented 40% of the European
plastic consumption and only 20% of the wastes of the total production
were recycled. To decrease the environmental impact of packaging on waste
management, an alternative consists in the use of biodegradable polymers.
This class of polymers has undergone a significant growth over the past ten
years and many researches are now focused on the optimization of their
properties (mechanical resistance, durability, permeability…) in order to
substitute conventional non-biodegradable materials.
Heat-shrinkable films are one of packaging products that are used
for wrapping bottles or cans. Up to now these films are produced either by
blowing process or by cast film extrusion and consisted in blends of low
density polyethylene (LDPE) and linear low density polyethylene (LLDPE).
For example, in the cast film extrusion, the molten polymer is
extruded through a slit die, stretched in a single machine direction by a
take-up device. It is then quenched in the air while being stretched and
finally cooled on chill-rolls. During the stretching, the polymer
macromolecules become oriented in some extent related to the structure and
the processing conditions. When reheated in a range between its glass
transition temperature (Tg) and melt temperature (Tm) the polymer film
shrinks and the shrinkage stress compels the products to gather tightly.
To our knowledge, no commercial grades of heat shrinkable films
made of biodegradable polymers are available hence the importance of the
present study. The first part is dedicated to investigate the influence of
blending linear and branched macromolecular structure on rheological
behavior and draw ratio on the shrinkage properties of the biodegradable
polyester (BP) casted films produced.
Experimental
A linear and a branched biopolyester (respectively LBP and BBP)
and three blends of variable proportions in weight (20/80%, 50/50%,
80/20% BBP/LBP) have been processed into films with a single screw
extruder (Thermofisher Polylab OS with Rheomex 19/25 unit) equipped
with a slit die of 270mm. The die gap was kept constant at 0.450mm. Each
blend was stretched at increasing draw ratio (E) by a take-up unit with a set
of chill-rolls cooled with circulating liquid inside and maintained at 7°C.
The dynamical rheological measurements of LBP, BBP and their
blends were performed using a strain controlled rheometer ARES (TA
Instrument) equipped with a 25mm parallel plates geometry in oscillatory
shear mode at 150°C, 170°C and 190°C. Two types of tests were
conducted: (i) the frequency sweep at strain ε=5% within the ω range from
100 to 0.01 rad.s-1; (ii) the rate sweep within the range of rate from 0.01 to
10s-1.
The extensional rheology behavior is measured with an Extensional
Viscosity Fixture (EVF) between 1 and 10s-1 and adjusted temperatures so
that the regime is set between stretch (strain-hardening) and pure reptation
dynamics (shear-thinning). All measurements were reproduced twice and
were well reproducible.
The heat-shrinkability of BP casted films was measured through two
types of tests: (i) restraint shrinkage tests are conducted with a TMA 50N
(Metravib) with an upside down frame configuration, immerged in an oil
bath maintained at Tm+15°C to investigate the shrinkage stress; (ii) free
shrinkage are conducted through immersion in an oil bath at Tm+ 15°C (+/2°C) during 120s (+/- 5s) to analyze the shrinkage rate.
Results and discussion
Comparing the Carreau-Yasuda model parameters of LBP and BBP
under shear-flow, any major difference had been highlighted. Under
elongational flow though, a shift along the lower temperature is required to
obtain a strain-hardening for LBP than for BBP.
Regarding the shrinkage characteristics, adding BBP in LBP (and
increasing draw ratio E) induced an increase of both the shrinkage rate from
55% to 75% at low E and 80% to 90% at high E and the shrinkage stress
from 0.05 MPa to 1 MPa at low E and 0.25 to 0.35 at high E. Considering
the structure, LBP lead to a lower shrinkage stress and rate whatever the
draw ratio tested.
Conclusions
These preliminary results have revealed a promising level of heatshrinkability of BP casted films suggesting the possibility of using them as
alternatives to polyethylene based films for heat shrinkable packaging
applications. The rheological behavior of LBP and BBP exhibit different
responses to a unique solicitation (same process geometry) leading to
different shrinkage rates and stresses even though the processing conditions
were kept the same. BBP always exhibit a higher strain-hardening than LBP
under extensional flow. These behavior was highlighted under elongational
deformation because of the higher sensitiveness of this technique to the
LCB level.
Further investigations will concern the determination of the required
branching structure for BP casted films inducing a controlled shrinkage by
blending linear and branching BP.
Lizeth Lopez
Ingénierie des Agro-Polymères et Technologies Emergentes
Biochemical and Structural Characterization of two Acacia gum
species: Acacia Senegal and Acacia Seyal
Acacia gum is a natural complex arabinogalactan polysaccharide
exuded from Acacia trees. Acacia Senegal is commonly used in food and
non-food applications as emulsifying, stabilizing, and coating ingredient.
Currently, Acacia Seyal is also gaining importance in the food industry.
However, only few studies focused on this variety. The aim of this study
was then to characterize and compare the biochemical and structural
features of Acacia Senegal and Acacia Seyal gums.
Biochemical analysis showed similarities between both varieties in
their main structure but also differences in their sugar composition,
distribution, and mode of branching. Acacia Senegal and Acacia Seyal were
mainly formed by 1→3,6-linked β-D-Galactopyranosyl residues, 1→3 αArabinosyl residues, and terminal Arabinofuranoses. However, Acacia
Senegal contained more branched Galactopyranosyl residues and shorter
Arabinosyl side branches than Acacia Seyal. Size exclusion
chromatography coupled to light scattering, refractometry, and viscosimetry
showed that although Acacia Seyal had larger molecular weight, it was
more compact and less viscous than Acacia Senegal. Conformation in
solution was also variety-dependent. In conclusion, even though Acacia
Senegal and Acacia Seyal display similar characteristics, this study
evidenced differences in their branching organization and physical
conformation that could be at the origin of differences in their functional
properties.
Sarah Bellini
Information et Technologies pour les Agro Procédés
Multispectral Optics in complex media: theory and application to the
monitoring of microalgal culture in a context of mass production
Microalgae are seen as a viable source of biofuels or biogas, beside
cultivation for human and animal feeding, or to extract high-value
chemicals and pharmaceuticals. Cultivation processes are being tested for
mass production and growth models, based on a set of measurements on the
culture medium, are developed in order to settle a complete monitoring of
the farming. However the complete analysis is hard to set-up and implies
many long-time samples preparations and high-cost measuring devices.
Microalgae community is looking forward to a quick measurement that
would give direct information about the algae chemical (pigments rate) and
physical (size of the cells, biomass) states. For this purpose, utilizing visible
(VIS) and near infrared (NIR) spectroscopy is looked as a promising
operational solution, as it is a fast measurement process widely used in life
sciences. Moreover, previous studies demonstrated that the absorption and
scattering coefficients of micoalgal suspensions in the VIS-NIR domain
depend heavily on the chemical characteristics (mainly nature and
concentration of pigments) and physical characteristics of the cells (size,
density of the cells).
The thesis aims first at developing a sound measurement method,
and second at building an interpretation theory linking the chemical and
physical characteristics of the algal cells to the measured spectra. Due to
significant scattering phenomena, optically complex media such as dense
algal media require a careful measurement protocol: a measurement method
relying on a dedicated optical setup and a precise measurement protocol
was thus investigated. A double integrating sphere (DIS) setup was
implemented and calibrated by means of a complete study of the
photometrical performances of the system. The setup and the measurement
protocol were validated on microsphere phantom suspensions. The
measurement method was proved to be adapted to measure adequately the
reflected and transmitted signals of highly scattering media, and in
particular of dense algal culture samples. The optical properties of an algal
cell can be adequately simulated using extended Mie theory for a
multilayered sphere. In a first approach, the algal cells were described as
spheres composed of concentric layers of different materials representing
the main organic substances encountered. From the width and complex
refractive index of each layer, the extended Mie theory makes it possible to
retrieve the extinction cross section of one cell. Based on this theory, the
AlgaSim simulation program was implemented to simulate the optical
coefficients of an algal population described by chemical and physical
parameters.
The spectral measurement setup coupled with the inversion of
AlgaSim was tested on real algal samples of two different strains taken at
three successive growth stages: the retrieved physical and chemical
characteristics were compared to measurements made with the standard
methods, microscope counting and flow cytometry for the cell number and
size, and HPLC for the pigment content. The spectroscopic method revealed
to predict the cell number and size with a relative error below 10% for both
strains. Moreover, the photopigments content and proportions were
obtained with a good precision at each growth stages. Those results are very
promising and indicate that the spectral measurement technique coupled
with the optical simulation implemented can be used as an alternative way
to determine the algal cell physiological state in routine.
Nakry Pen
Institut Européen des Membranes
An innovative membrane bioreactor for methane biohydroxylation
Methane constitutes a large carbon feedstock, which can potentially
be used for the production of liquid oxygenated products serving in fine
chemistry, such as methanol or formic acid. The development of processes
allowing the methane biohydroxylation, i.e. methane conversion into
methanol, is thus of great interest. The high stability of C-H bond induces
however strong methane inertness and its chemical activation still remains
unselective and energy consuming despite recent progress. The microbial
hydroxylation of methane by aerobic methanotrophic bacteria is a
promising alternative as this bioconversion is specific and performed in
mild conditions. The non-pathogenic methanotrophic bacteria Methylosinus
trichosporium OB3b was notably identified as an efficient biocatalyst for
the methane hydroxylation.
A new membrane bioreactor (MBR) was developed at the European
Membrane Institute, France to achieve the microbial methane hydroxylation
by M. trichosporium OB3b. This innovative MBR couples a bioreactor to
two gas/liquid microporous membrane contactors. This MBR was operated
in fed-batch mode: the bacterial suspension circulates in closed loop within
the contactors allowing a continuous feeding of the two gaseous substrates
(methane and oxygen) into the reaction medium. Using gas/liquid
microporous membrane contactors offers not only a large exchange surface
which ensures the reaction medium saturation but also a safety operating by
avoiding the formation of gas bubbles into the reactor that could generate an
explosive gas mixture.
In this study, the feasibility and the reproducibility of this new
biohydroxylation process were demonstrated. A mean productivity of 74 ±
23 mg methanol.(g dry cell)-1.h-1 was obtained. This productivity was
nearly 35-fold higher than the one reported for the sole fed-batch bioreactor
using the membrane technology to our knowledge, in which the gaseous
substrates were fed through two dense silicone tubes immerged into the
reaction medium. This result evidenced that microporous membranes
allowed a much better gas/liquid transfer compared to dense membranes.
Besides, the reached productivity appeared to be similar to the
productivities reported for either continuous or fed-batch bioreactors (75 80 mg methanol.(g dry cell)-1.h-1) that were all operated with a bubble
sparger for gas supply.
The hydroxylation performance of this new MBR was finally
compared to the one obtained within a batch reactor operated with similar
conditions. The average productivity for this batch reactor (42 ± 25 mg
methanol.(g dry cell)-1.h-1) was significantly lower, which was due to a
less efficient gas/liquid transfer leading to a substrate limitation into the
batch reactor.
Posters
Doctorant
Nicolas Tarlier
Alexandre Rubio
José Acera Fernández
Morgan Chabannes
UMR
Titre
ICGM
Preliminary characterization of a textured
mannitol compactibility using a rotary
tablet press simulator
BioWooEB
C2MA
C2MA
Natural rubber latex co-product
valorization: tangential filtration
optimization through a physico-chemical
approach*
Développement des traitements et des
procédés de fonctionnalisation de surfaces
des fibres végétales pour application
matériaux composites
Filippo Acerbi
IATE
Simultaneous assesment of solubility and
diffusivity coefficients of carbon dioxide
in cheese
guilherme De oliveira reis
IATE
Rheological properties and strain
hardening in Hevea brasiliensis latex gels
Fabien Bibi
IATE
Dielectric properties of vegetal proteins
for the developement of green RFID biosensors
IATE
Optimization of Chemo-Mechanical
Pretreatments in Semi-humid medium of
Lignocellulosic Biomass for Biofuels
Production
Claudia Grajeda-Iglesias
IATE
Evaluation of antioxidant activity of
protocatechuic acid esters by the CAT
Method
Vincent Raggiri
IATE
Durum wheat milling value: an important
criteria to investigate*
Sébastien Rolere
IATE
Santi Chuetor
Adriaan Van der Mijnsbrugge
IATE
Mechano-chemical model study of the
mixing process of flour/water mixtures in
the context of the industrial wheat
gluten-starch separation process*
Erika Zago
IATE
Extraction and enzymatic transformation
of phenolic molecules from oilseeds
IATE
Multi-scale modelling of structure and
mass transfer properties relationship –
Application to biomaterials based
composites
Marie-Alix Berthet
IATE
Poly-(3-hydroxybutyrate-covalerate)/Wheat Straw biocomposites for
food packaging: structure-processingproperties relationships
Ian Soulairol
ICGM
New apparatus for measuring swelling
functionality of super-disintegrants
Caroline Wolf
Design of a lightweight insulating concrete
using rice husk
Ameni Lahdhiri
IEM
Nils Kuster
NUTRIPASS
Damien Wlodarczyk
IEM
Elaboration de membranes à base de
chitosane par gélification enzymatique*
Jennifer Biscarat
IEM
Preparation of sustainable bioartificial blend
membranes for gas separation
Michel Rivier
Qualisud
IEM
Sweep Gas Membrane Distillation using
Stainless-Steel Hollow -Fibers: from material
to process
Céline Bigot
Qualisud
Bactericidal study of a Al2O3-TiO2-Ag
material in a fixed-bed reactor for
continuous spa water disinfection
Layal Dahdouh
Qualisud
Guilhem Raffray
Qualisud
Sushumna Shukla
Marie-Anne Tartanson
IEM
Quentin Ricoux
IEM
Sorption sélective du palladium sur un
matériau polymère innovant à base
d'aminophosphine
Majid Al Heidary
ITAP
Identification of nozzles macroscopic
descriptors for spray drift modeling
ITAP
Développement d'un modèle pour
l'évaluation environnementale des
systèmes d'eau urbains dans le cadre
conceptuel de l'Analyse du Cycle de Vie
(ACV)
Elisabeth Cazier
LBE
Inhibition of dry AD of wheat straws by
hydrogen
Violette Thuron
LBE
Philippe Loubet
Caroline Baroukh
Sofiane Mazeghrane
Caroline Baroukh
Quentin Aemig
LBE
LBE
LBE
LBE
A new framework for metabolic modelling
under non-balanced growth. Application to
photoautotrophic microalgae in day/night
cycle
Thibaut Bontpart
SPO
Souhir Marsit
SPO
Nicolas De Royer Dupre
SPO
Christelle Bressuire
SQPOV
Cécile Labadie
SQPOV
Estimation of age- and comorbiditiesadjusted percentiles of high-sensitivity
cardiac troponin T levels and risk
stratification in elderly
Semi-empirical models of heat transfer
and friction factor in a tubular heat
exchanger with turbulators
Comparative analysis of the microbial
ecology of organic and conventional
fruits
Identification of relevant fruit juices
characteristics for the prediction of
microfiltration performance
Multi-objective optimization of the
design of food processes
Vers la caractérisation de gènes
influençant l'astringence des tanins
condensés chez la Vigne
Adaptative role of horizontally
transferred oligopeptide transporters in
wien yeasts
vine water status and aroma potential:
the case of grenache noir and shiraz
grapes
Characterisation of spoilage microflora in
Rose flower and Orange blossom
hydrosols
*: Sous reserve (problème de confidentialité)
Liens Utiles
-Ecole doctorale SP-SA : http://www.edspsa.univ -montp2.fr/
- LinkendIn : http://www.linkedin.com/groups/Ecole -Doctorale -SPSA
- UMR CMGD /EMA : http://www.ensm -ales.fr/CMGD/index.html
- UMR IATE : http://umr -iate.cirad.fr/index.php
- UMR IEM : http://www.iemm.univ -montp2.fr/
- UMR ITAP : http://itap.irstea.fr/
-UMR LBE : http://www4.montpellier.inra.fr/narbonne
- UMR NUTRIPASS : http://www.nutripass.ird.fr/
- UMR QUALISUD : http://umr -qualisud.cirad.fr/
- UMR SPO : http://www5.montpellier.inra.fr/spo/
-UMR SQPOV : http://www.univavignon.fr/fr/recherche/laboratoires/strlab/structure/unite-mixte-derecherche-a408-qualite-et-securit.html
- UR Bois Tropicaux: http://ur-bois-tropicaux.cirad.fr/