TECHNOLOGIES FOR BIOREACTORS - ONLINE METROLOGY - DETECTION OF VFAs USING ELECTROCHEMICALLY MODIFIED ELECTRODES

Biochemical approaches using electrochemical transduction were investigated for monitoring Volatile Fatty Acids (VFAs). Modified electrodes were obtained by means of electrodeposition technique. Cyclic voltammetry and square wave voltammetry (SWV) revealed that some oxidation and reduction peaks were shifted in the presence of acetic acid. These electrodes based on macrocyles are promised tools for VFAs detection.

Structure of macrocycles.		SWV curves of Au SPE-TPPH2 with addition of the acetic acid. Potential step=10mV; potential pulse=60mV;  frequency=15Hz.

     
Post doc: S. Delile, A. Ndiaye

Contracts: ANR LabEx IMobS3, Challenge 3, Action Bioenergy Production Processes (2012-2016) / Invited Professor M.L. Rodriguez-Mendez for VFAs detection issues

Selected papers:
•    Detection of acetic acid using electrochemically modified electrodes based on metallophthalocyanines and porphyrins derivatives, A.L. Ndiaye et al., Electrochimica Acta (2015).
•    Electrodes modification based on metal free phthalocyanine: example of electrochemical sensors for the detection of acetic acid, A.L. Ndiaye et al., Journal of Sensors (2015).

BIOPROCESSES INTENSIFICATION WITH HIGH FREQUENCY ELECTROMAGNETIC FIELDS

Bi-compartmented experimental device was designed to evaluate the effects of high frequency, high intensity electromagnetic waves in eukaryotic cells. Dielectric properties were measured; an electromagnetic simulation code allowed the determination of the electromagnetic field inside the reactor. The simulations showed that the shape of the reactor has a major influence on both attenuation of the electromagnetic waves in the culture medium and the orientation of the field.

Schematic overview of the experimental device and picture and mesh of the secondary reactor placed inside the exposure chamber.		(left) Culture medium relative permittivity and conductivity during the cultivation of Saccharomyces cerevisiae. (right) Cartesian decomposition of the simulated electric field in the secondary reactor at 900 MHz according to the main sectional plane z = 0. (a) Empty reactor, (b) reactor filled with the culture medium.

        

Post doc: E. Bertrand

Contracts: ANR LabEx IMobS3, Challenge 3, Action BioEM (2012-2014)

Selected papers:
•    Design d’un bioréacteur permettant de suivre des cultures de microorganismes soumises à un champ électromagnétique, A. Pons et al., Récents Progrès en Génie des Procédés 104, Ed SFGP, Paris (2013).
•    Caractérisation d’un bioréacteur pour la culture de Saccharomyces cerevisiae soumis à des champs électromagnétiques en environnements anéchoïques et réverbérants, E. Bertrand et al., In Proceedings du 17ème Colloque International et Exposition sur la Compatibilité Electromagnétique, Clermont-Ferrand (2014).

LIGHT SCATTERING PROPERTIES BY ARBITRARY SHAPED PARTICLES

A new code based on the Fourier Modal Method was developed for computing optical properties of particles with arbitrary shapes and large aspect factor (non spherical particles). The model implements 2D analytic modelling of matched layers stacked into a 3D object.

Scattering cross sections of oblate spheroids normalized by the area  of the same volume as a function of the size parameter of the sphere for oblate  spheroids with refractive index n=1.33 and a/b=1.5, 2, 3 and 5. Our results and those of Asano are indistinguishable.

Post doc: M. Abboud

Contracts: ANR LabEx IMobS3, Challenge 3, Action Bioenergy Production Processes (2011-2020)

Selected papers:
•    Computation of spheroidal micro-organisms cross sections using the Aperiodic Fourier Modal Method, M. Abboud et al., PIERS Proceedings, Prague (2015).