Fructo-oligosaccharides (FOS) are non-digestible sweeteners with improved functional and technological properties for food and pharmaceutical industry applications. The immobilization of FOS-producing microorganism's whole cells can be used to improve the production of FOS and so, an accurate choice of the carrier is of crucial importance. Here we present a screening and selection of carriers for immobilization of Aureobasidium pullulans cells with potential for yielding high FOS production. Synthetic, agro-industrial by-products and mineral materials were tested and selected regarding their ability to immobilize cells, as well as their potential to produce FOS, through shaken-flask fermentations. Increased amounts of immobilized cells were found for carriers with higher porosity observed at the microscope, higher water absorption index (WAI) and lower critical humidity point (CHP). Reticulated polyurethane foam was one of the most efficient synthetic carriers immobilizing cells (over 75% (w/w) of the total cells were immobilized). Also, high FOS production was obtained: FOS concentration, purity and yield increased in 15, 8 and 12% (w/w), respectively, as compared to free cells conditions. Although walnut shell had a much lower immobilization efficiency, the high amount of cells grown while using this carrier led to a highest increment of FOS concentration, purity and yield, namely, 27, 10 and 25% (w/w). Cells immobilization with the selected carriers holds great promise for FOS production on a larger scale.

Title: Green and sustainable production of high value compounds via a microalgae encapsulation technology that relies on CO 2 as a principle reactant This research article highlights the extraordinarily long-term viability and high activity of microalgae entrapped within an alginate-silica hybrid matrix, holding much promise for the design of new generation fi xed biomass photobioreactors that are based on microencapsulation technology. This bionanotechnology opens up exciting avenues for the design of photosynthetic solar cells and artifi cial trees for a green and sustainable production of high value compounds and electricity on the basis of photosynthesis process.A very promising and facile one-pot synthesis pathway is presented for the microencapsulation of live cells in a very porous core-shell system based upon a robust matrix. (Alginate-SiO 2 -polycation)shell@(alginate-SiO 2 ) core hybrid beads, on the millimeter scale, containing live cells are obtained through cross-linking chemistry and the polycondensation of silicic acid in conjunction with the use of a polycation to negate the surface charge on silica. Very interestingly it is revealed that the polycation used (PDADMAC) plays a very important role in the formation of highly robust core-shell beads. PDADMAC acts as a catalyst in the polycondensation of silicic acid, leading to the formation of a resistant double layer shell comprising of an interior layer of alginate-SiO 2 with a very homogeneous distribution of porous SiO 2 and an external layer of porous PDADMAC that confines SiO 2 within the bead. The photosynthetic chlorophyta Dunaliella tertiolecta, which produces high value metabolites (such as antioxidants, pharmacologically active compounds, neutraceuticals etc.) via photosynthesis, has been encapsulated within this core-shell system. Oximetry and fluorescence measurements highlight how this algal culture can remain photosynthetically active over an extraordinarily long period of 13 months for high value compound production, whilst entrapped within a highly porous, mechanically and chemically stable, optically transparent matrix, with no observable leaching of the cells from the core of the beads. HPLC has been employed to highlight the presence of excreted metabolites, based on neutral sugar building blocks such as arabinose, galactose and xylose, in the surrounding media. These results reveal how this kind of high performance, low-cost, and easily scaleable core-shell living material could be employed in large scale photobioreactors (PBRs), to potentially facilitate metabolite harvesting whilst protecting the culture from external contamination and for green energy production and environmental (CO 2 ) remediation.

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Volatile organic compounds (VOCs) are one of the main contributors to air pollution. To reduce anthropogenic emissions, it is necessary to improve existing techniques such as catalytic oxidation through the development of new cost-effective catalysts. Although many studies deal with the development and testing of new materials, most are performed at laboratory scale, of which only a few study mixtures of VOCs. To assess their viability for industrial applications, further tests are required, namely, mixture tests at intermediate scale in relevant environment and extrapolated on an industrial scale. In this work, the catalytic performance of a new mixed oxide CoAl -Ce was investigated towards the oxidation of the n-butanol and toluene on a semi-pilot scale (TRL 4). Single component and mixture experiments were performed for several concentrations at a fixed flow rate. A commercial catalyst Pd/γ-Al 2 O 3 was used as the benchmark to evaluate the performance of the mixed oxide. The CoAl -Ce catalyst enables complete oxidation of n-butanol at the same temperature as the reference catalyst. Moreover, it provides a better selectivity for n-butanol, while providing an equivalent one for the oxidation of toluene. In mixtures, the presence of n-butanol promotes the oxidation of toluene for both catalysts but more significantly for the CoAl -Ce catalyst. The presence of toluene inhibits the oxidation of n-butanol for the CoAl -Ce and promotes it for high conversions of n-butanol for the Pd/γ-Al 2 O 3 catalyst. K E Y W O R D S catalytic oxidation, mixed oxide, semi-pilot scale, VOC abatement 1 | INTRODUCTION Volatile organic compounds (VOCs) are one of the main contributors to air pollution. They are responsible for several environmental problems, such as ozone layer depletion, the formation of tropospheric ozone, and ground level smog. Moreover, they are dangerous for human health. [1,2] The concern for air quality and preservation of the environment has led to several international efforts to improve policies regarding emission levels of air pollutants. The United Nation Economic Commission for Europe (UNECE) has developed strategies to reduce † This article was presented at the SFGP Congress in Nantes, France in 2019.