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Procédé enzymatique intensifié et durable de N-acylation d'acides aminés en milieux écocompatibles : caractérisation, cinétiques et immobilisation de nouveaux biocatalyseurs

Abstract : Acylated amino acids are one of the most attractive biobased surfactants for food, cosmetic and pharmaceutic industry regarding their techno-functional and bioactive properties. Those molecules are produced at industrial scale by using Schotten-Baumann chemical method which is a very productive way but non-specific and have a negative impact on the environment. Enzymatic catalysis is one of the most promising alternatives. The aim of this work was to find the best enzymatic way for the N-acylation of amino acids in green solvent. The first step was to select the couple enzyme / reactional medium enabling the implementation of this reaction. Aminoacylases from Streptomyces ambofaciens in aqueous medium showed the best N-acylation specificity towards the amino acids and the acyl donors with some correlating between the structure of the substrates and the catalytic performances compared to CALB which doesn’t show any N-α-acylation activity. The addition of cobalt to the reaction medium allowed an acceleration of the reaction rate and an increase of the activity. In a second time, the activity of the different enzymes was evaluated after the immobilization on various supports. The aminoacylases immobilized on SBA-15 functionalized with APTES showed the best performances compared to the use of the others supports but a decrease of the activity compared to the free enzymes was observed. In the case of CALB, the covalent immobilization using isocyanate as grafting agent on the macroporous silica material allowed a significant improvement of the catalytic performance under scCO2 even better than the commercial immobilized CALB. Lastly, the operational condition affecting the aminoacylases activity for the synthesis of undecenoyl-phenylalanine, a product with cosmetic interest, was evaluated. The product of the reaction was purified to >99% and the skin depigmentation activity was checked.
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http://docnum.univ-lorraine.fr/ulprive/DDOC_T_2020_0114_BOURKAIB.pdf
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https://hal.univ-lorraine.fr/tel-03004673
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Submitted on : Friday, November 13, 2020 - 5:11:31 PM
Last modification on : Saturday, November 14, 2020 - 3:26:26 AM

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  • HAL Id : tel-03004673, version 1

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Mohamed Chafik Bourkaib. Procédé enzymatique intensifié et durable de N-acylation d'acides aminés en milieux écocompatibles : caractérisation, cinétiques et immobilisation de nouveaux biocatalyseurs. Génie des procédés. Université de Lorraine, 2020. Français. ⟨NNT : 2020LORR0114⟩. ⟨tel-03004673⟩

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