Corvini, Philippe
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Enzymes for consumer products to achieve climate neutrality
Today, the chemosphere’s and biosphere’s compositions of the planet are changing faster than experienced during the past thousand years. CO2 emissions from fossil fuel combustion are rising dramatically, including those from processing, manufacturing and consuming everyday products; this rate of greenhouse gas emission (36.2 gigatons accumulated in 2022) is raising global temperatures and destabilizing the climate, which is one of the most influential forces on our planet. As our world warms up, our climate will enter a period of constant turbulence, affecting more than 85% of our ecosystems, including the delicate web of life on these systems, and impacting socioeconomic networks. How do we deal with the green transition to minimize climate change and its impacts while we are facing these new realities? One of the solutions is to use renewable natural resources. Indeed, nature itself, through the working parts of its living systems, the enzymes, can significantly contribute to achieve climate neutrality and good ecological/biodiversity status. Annually they can help decreasing CO2 emissions by 1–2.5 billion-tons, carbon demand by about 200 million-tons, and chemical demand by about 90 million-tons. With current climate change goals, we review the consequences of climate change at multiple scales and how enzymes can counteract or mitigate them. We then focus on how they mobilize sustainable and greener innovations in consumer products that have a high contribution to global carbon emissions. Finally, key innovations and challenges to be solved at the enzyme and product levels are discussed.
Cyclodextrin-based polymeric materials for the specific recovery of polyphenolic compounds through supramolecular host-guest interactions
While the specific recovery of valuable chemicals from waste streams represents an environmentally-friendly and potentially economically-relevant alternative to synthetic chemical productions, it remains a largely unmet challenge. This is partially explained by the complexity of designing sorption materials able to target one specific compound and able to function in complex matrices. In this work, a series of cyclodextrin-based polymers (CDPs) were designed to selectively extract phenolic compounds from a complex organic matrix that is olive oil mill wastewater (OMW). In order to endow these polymers with selective adsorption properties, several monomers and cross-linkers were screened and selected. The adsorption properties of the CDPs produced were first tested with selected phenolic compounds commonly found in OMW, namely syringic acid, p-coumaric acid, tyrosol and caffeic acid. The selected CDPs were subsequently tested for their ability to adsorb phenolic compounds directly from OMW, which is known to possess a high and complex organic content. It was demonstrated through high-performance liquid chromatography-mass spectroscopy analyses that efficient removal of phenolic compounds from OMW could be achieved but also that two compounds, namely tyrosol and hydroxytyrosol, could be selectively extracted from OMW.
Template-free hierarchical self-assembly of a pyrene derivative into supramolecular nanorods
The accurate molecular design of organic building blocks is of great importance for the creation of large supramolecular entities with precise dimensional organisation. Herein we report on the design of a new pyrene derivative that yields, through a hierarchical self-assembly process and in the absence of template, stable and well defined nanorods. X-ray diffraction studies allowed elucidation of the three dimensional packing of this pyrene derivative within the self-assembled nanorods.
High efficient photocatalytic reduction of nitrate to N2 by Core-shell Ag/SiO2@cTiO2 with synergistic effect of light scattering and surface plasmon resonance
Photocatalytic denitrification has attracted great attention owing to its high efficiency and environmentally friendly features. However, selectively photocatalytic reduction of high concentration nitrate to N2 is still a challenging problem due to the competition of photons between nitrate and photocatalysts. Herein, the Ag/SiO2 core encapsulated in the crystalline TiO2 shell (Ag/SiO2@cTiO2) was constructed for improvement of photocatalytic denitrification. Finite difference time domain (FDTD) simulation demonstrated that strong light scattering improved light harvesting via optical confinement. Meanwhile, surface plasmon resonance and electron sink effect of Ag not only enhanced the photogenerated electrons density but also promoted charge carriers separation of Ag/SiO2@cTiO2. More importantly, ecb− of TiO2-shell could be immediately transferred to Ag to keep the balance between Ag0 and Ag+, which contributed to the good stability of Ag/SiO2@cTiO2. 95.8% nitrate (C0 = 2000 mg/L) was removed by 5 wt%Ag/SiO2@cTiO2 with N2 selectivity of 93.6% within 4 h. Even after five cycles, 5 wt%Ag/SiO2@cTiO2 still remained high photocatalytic denitrification efficiency (92.2%). Notably, since TiO2-shell prevented the reaction between Ag and Cl−, more than 92% nitrate could be removed within 5.3 h in the presence of high concentration Cl−.
Enzyme Armoring by an Organosilica Layer: Synthesis and Characterization of Hybrid Organic/Inorganic Nanobiocatalysts
The availability of highly stable and reusable enzymes is one of the main challenges in bio-based industrial processes. Enzyme immobilization and encapsulation represent promising strategies to reach this goal. In this chapter, the synthetic strategy to produce hybrid organic/inorganic nanobiocatalysts (NBC) is reported. This strategy is based on the sequential immobilization of an enzyme on the surface of silica nanoparticles followed by the growth, at the surface of the nanoparticles, of a shielding layer which serves as an armor to protect the enzyme against denaturation/degradation. This armor is produced through a thickness-controlled organosilane poly-condensation onto the nanoparticle surface around the enzyme to form a protective organosilica layer. The armored nanobiocatalysts present enhanced catalytic activity and improved stability against heat, pH, chaotropic agents, proteases, and ultrasound. The method is versatile in that it can be successfully adapted to a number of different enzymes.
Supramolecular enzyme engineering in complex nanometer-thin biomimetic organosilica layers
The use of enzymes in industrial processes is often hampered by their limited stability under operational conditions. As enzymes' function and stability are directly correlated to their three-dimensional structure, numerous methods aiming at the preservation of this structure have been developed. While stabilization can be achieved using solid scaffolds for encapsulating the enzyme, it often results in loss of enzymic activity owing to a lack of conformational mobility of the biocatalyst. With the idea of mimicking protein-protein interactions to create a network of weak force interactions between the surface of an immobilized enzyme and a synthetic protective layer, we have developed a chem. strategy allowing the use of complex mixts. of building blocks mimicking the lateral chain of natural amino acids. After crosslinking a model enzyme at the surface of silica nanoparticles, incubation with eight different organosilane mixts. allowed growing protective organosilica layers of controlled thicknesses. The nanoparticles produced were characterized by SEM and their biocatalytic activity was measured under a series of operational stress conditions. Our results clearly demonstrated that increasing the complexity and biomimetic nature of the protection layer allowed for relevant improvement of the protection effect. Indeed, when compared with the basic formulation, selected complex formulations allowed for an improvement of up to 100% when treated at 50 °C for 60 min or in the presence of a denaturing detergent (SDS).
Hydrophobicity-responsive engineered mesoporous silica nanoparticles: application in the delivery of essential nutrients to bacteria combating oil spills
Facile chemical modification of mesoporous silica particles allows the production of gated reservoir systems capable of hydrophobicity-triggered release. Applied to the delivery of nutrients specifically to an oil phase, the systems developed have been shown to reliably assist the bacterial degradation of hydrocarbons. The gated system developed, made of C18 hydrocarbon chains, is demonstrated to be in a closed collapsed state in an aqueous environment, yet opens up through solvation by lipophilic alkanes and releases its content on contact with the oil phase.
A Biocatalytic Nanomaterial for the Label-Free Detection of Virus-Like Particles
The design of nanomaterials that are capable of specific and sensitive biomolecular recognition is an on-going challenge in the chemical and biochemical sciences. A number of sophisticated artificial systems have been designed to specifically recognize a variety of targets. However, methods based on natural biomolecular detection systems using antibodies are often superior. Besides greater affinity and selectivity, antibodies can be easily coupled to enzymatic systems that act as signal amplifiers, thus permitting impressively low detection limits. The possibility to translate this concept to artificial recognition systems remains limited due to design incompatibilities. Here we describe the synthesis of a synthetic nanomaterial capable of specific biomolecular detection by using an internal biocatalytic colorimetric detection and amplification system. The design of this nanomaterial relies on the ability to accurately grow hybrid protein-organosilica layers at the surface of silica nanoparticles. The method allows for label-free detection and quantification of targets at picomolar concentrations.
Enzyme Shielding in an Enzyme-thin and Soft Organosilica Layer
The fragile nature of most enzymes is a major hindrance to their use in industrial processes. Herein, we describe a synthetic chem. strategy to produce hybrid org./inorg. nanobiocatalysts; it exploits the self-assembly of silane building blocks at the surface of enzymes to grow an organosilica layer, of controlled thickness, that fully shields the enzyme. Remarkably, the enzyme triggers a rearrangement of this organosilica layer into a significantly soft structure. We demonstrate that this change in stiffness correlates with the biocatalytic turnover rate, and that the organosilica layer shields the enzyme in a soft environment with a markedly enhanced resistance to denaturing stresses.