Fungal Glucuronoyl and Feruloyl Esterases for Wood Processing and Phenolic Acid Ester/Sugar Ester Synthesis

Feruloyl esterases (FAEs, E.C. 3.1.1.73, CAZy family CE1) and glucuronoyl esterases(GEs, E.C. 3.1.1.-, CAZy family CE15) are involved in the degradation of plantbiomass by hydrolysing ester linkages in plant cell walls, and thus have potential use inbiofuel production from lignocellulosic materials and in biorefinery applications withthe aim of developing new wood-based compounds [1, 2]. GEs and FAEs are present inthe genomes of a wide range of fungi and bacteria.Under conditions of low water content, these enzymes can also carry out(trans)esterification reactions, making them promising biocatalysts for the modificationof compounds with applications in the food, cosmetic and pharmaceutical industry.Compared to the chemical process, enzymatic synthesis can be carried out under lowerprocess temperatures (50-60\ub0C) and results in fewer side products, thus reducing theenvironmental impact.We characterised new FAE and GE enzymes from mesophilic, thermophilic and coldtolerantfilamentous fungi produced in Pichia pastoris. The enzymes were characterisedfor both their hydrolytic abilities on various model substrates (methyl ferulate, pNPferulate)- for potential applications in deconstruction of lignocellulosic materials andextraction of valuable compounds - as well as for their biosynthetic capacities. Wetested and optimised the FAEs’ transesterification capabilities on ferulate esters in a 1-butanol-buffer system, with the aim of using the most promising candidates for theproduction of antioxidant compounds with improved hydrophobic or hydrophilicproperties, such as prenyl ferulate, prenyl caffeate, glyceryl ferulate and 5-O-(transferuloyl)-arabinofuranose

Fungal Glucuronoyl and Feruloyl Esterases for Wood Processing and Phenolic Acid Ester/Sugar Ester Synthesis

Feruloyl esterases (FAEs, E.C. 3.1.1.73, CAZy family CE1) and glucuronoyl esterases (GEs, E.C. 3.1.1.-, CAZy family CE15) are involved in the degradation of plant biomass by hydrolysing ester linkages in plant cell walls, and thus have potential use in biofuel production from lignocellulosic materials and in biorefinery applications with the aim of developing new wood-based compounds [1, 2]. GEs and FAEs are present in the genomes of a wide range of fungi and bacteria. Under conditions of low water content, these enzymes can also carry out (trans)esterification reactions, making them promising biocatalysts for the modification of compounds with applications in the food, cosmetic and pharmaceutical industry. Compared to the chemical process, enzymatic synthesis can be carried out under lower process temperatures (50-60\ub0C) and results in fewer side products, thus reducing the environmental impact. We characterized new FAE and GE enzymes from mesophilic, thermophilic and cold-tolerant filamentous fungi produced in Pichia pastoris. On one hand, we investigated their hydrolytic abilities on various model substrates for potential applications in deconstruction of lignocellulosic materials and extraction of valuable compounds. On the other hand, we tested and optimised the FAEs’ transesterification capabilities on ferulate esters in a 1-butanol-buffer system, with the aim of using the most promising candidates for the production of antioxidant compounds with improved hydrophobic or hydrophilic properties, such as prenyl ferulate, prenyl caffeate, glyceryl ferulate and 5-O-(trans-feruloyl)-arabinofuranose

Fungal Glucuronoyl and Feruloyl Esterases for Wood Processing and Phenolic Acid Ester/Sugar Ester Synthesis

Feruloyl esterases (FAEs, E.C. 3.1.1.73, CAZy family CE1) and glucuronoyl esterases (GEs, E.C. 3.1.1.-, CAZy family CE15) are involved in the degradation of plant biomass by hydrolysing ester linkages in plant cell walls, and thus have potential use in biofuel production from lignocellulosic materials and in biorefinery applications with the aim of developing new wood-based compounds [1, 2]. GEs and FAEs are present in the genomes of a wide range of fungi and bacteria. Under conditions of low water content, these enzymes can also carry out (trans)esterification reactions, making them promising biocatalysts for the modification of compounds with applications in the food, cosmetic and pharmaceutical industry. Compared to the chemical process, enzymatic synthesis can be carried out under lower process temperatures (50-60\ub0C) and results in fewer side products, thus reducing the environmental impact. We characterized new FAE and GE enzymes from mesophilic, thermophilic and cold-tolerant filamentous fungi produced in Pichia pastoris. On one hand, we investigated their hydrolytic abilities on various model substrates for potential applications in deconstruction of lignocellulosic materials and extraction of valuable compounds. On the other hand, we tested and optimised the FAEs’ transesterification capabilities on ferulate esters in a 1-butanol-buffer system, with the aim of using the most promising candidates for the production of antioxidant compounds with improved hydrophobic or hydrophilic properties, such as prenyl ferulate, prenyl caffeate, glyceryl ferulate and 5-O-(trans-feruloyl)-arabinofuranose

Synthesis of antioxidants with free and immobilised fungal feruloyl esterases

Feruloyl esterases (FAEs, E.C. 3.1.1.73, CAZy family CE1) are enzymes that are secreted by a wide range of fungi and bacteria as part of the enzymes hydrolysing plant biomass. Under conditions of low water content, FAEs can also carry out (trans)esterification reactions. Thus, their potential use as biocatalysts for the production of antioxidants with applications in food, cosmetic and pharmaceutical industries has been investigated in recent years. We characterised the biosynthetic potential of four new FAE enzymes from a thermophilic fungus. We focused on optimizing reaction conditions for the synthesis of ferulate esters with improved hydrophobic or hydrophilic properties; prenyl ferulate and 5-O-(trans-feruloyl)-arabinofuranose, respectively. In addition to using free enzymes, we also immobilised them on the mesoporous silica material SBA-15 with pore sizes ranging from 7 to 10 nm, to improve the esterification-to-hydrolysis ratio of the enzymes. It has been shown previously that immobilisation renders enzymes more resilient to adverse conditions and increases their productive life time [1]. Furthermore, immobilisation may also result in a decrease of unwanted side reactions (hydrolysis of transesterification) [2]. In agreement with that, we achieved a higher product yield with immobilised enzymes compared to free enzymes. The immobilised biocatalysts are also more easily re-usable for several production cycles, thus lowering production costs