Exploring the synergy between fungal CE15 glucuronoyl esterases and xylanases for lignocellulose saccharification.

Background: Lignin-carbohydrate complexes in lignocellulosic biomass act as a barrier to its biodegradation and biotechnological exploitation. Enzymatic dissociation between lignin and hemicellulose is a key process that allows the efficient bioconversion of both polymers. Glucuronoyl esterases of the Carbohydrate Esterase 15 family target the ester linkages between the glucuronic acid of xylan and lignin moieties, assisting enzymatic biodegradation of lignocellulose.

Design of Plastic Binding Lytic Polysaccharide Monooxygenases via Modular Engineering.

The worldwide accumulation of plastic waste in the environment, along with its lifespan of hundreds of years, represents a serious threat to ecosystems. Enzymatic recycling of plastic waste offers a promising solution, but the high chemical inertness and hydrophobicity of plastics pose several challenges to enzymes. In nature, lytic polysaccharide monooxygenases (LPMOs) can act at the surface of recalcitrant biopolymers, taking advantage of their solvent-exposed active sites and appended carbohydrate-binding modules (CBMs).

Functional Carbohydrate-Active Enzymes Acquired by Horizontal Gene Transfer from Plants in the Whitefly Bemisia tabaci.

Carbohydrate-active enzymes involved in the degradation of plant cell walls and/or the assimilation of plant carbohydrates for energy uptake are widely distributed in microorganisms. In contrast, they are less frequent in animals, although there are exceptions, including examples of carbohydrate-active enzymes acquired by horizontal gene transfer from bacteria or fungi in several of phytophagous arthropods and plant-parasitic nematodes. Although the whitefly Bemisia tabaci is a major agricultural pest, knowledge of horizontal gene transfer-acquired carbohydrate-active enzymes in this phloem-feeding insect of the Hemiptera order (subfamily Aleyrodinae) is still lacking.

In situ imaging of LPMO action on plant tissues.

Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that oxidatively cleave recalcitrant polysaccharides such as cellulose. Several studies have reported LPMO action in synergy with other carbohydrate-active enzymes (CAZymes) for the degradation of lignocellulosic biomass but direct LPMO action at the plant tissue level remains challenging to investigate. Here, we have developed a MALDI-MS imaging workflow to detect oxidised oligosaccharides released by a cellulose-active LPMO at cellular level on maize tissues.

The disordered C-terminal tail of fungal LPMOs from phytopathogens mediates protein dimerization and impacts plant penetration.

Lytic polysaccharide monooxygenases (LPMOs) are monocopper enzymes that oxidatively degrade various polysaccharides, such as cellulose. Despite extensive research on this class of enzymes, the role played by their C-terminal regions predicted to be intrinsically disordered (dCTR) has been overlooked. Here, we investigated the function of the dCTR of an LPMO, called AA9A, up-regulated during plant infection by , the causative agent of anthracnose.

Insights into peculiar fungal LPMO family members holding a short C-terminal sequence reminiscent of phosphate binding motifs.

Lytic polysaccharide monooxygenases (LPMOs) are taxonomically widespread copper-enzymes boosting biopolymers conversion (e.g. cellulose, chitin) in Nature.

A fungal lytic polysaccharide monooxygenase is required for cell wall integrity, thermotolerance, and virulence of the fungal human pathogen Cryptococcus neoformans.

Fungi often adapt to environmental stress by altering their size, shape, or rate of cell division. These morphological changes require reorganization of the cell wall, a structural feature external to the cell membrane composed of highly interconnected polysaccharides and glycoproteins. Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that are typically secreted into the extracellular space to catalyze initial oxidative steps in the degradation of complex biopolymers such as chitin and cellulose.

Rational engineering of AA5_2 copper radical oxidases to probe the molecular determinants governing their substrate selectivity.

Fungal copper radical oxidases (CROs) from the Auxiliary Activity family 5 (AA5) constitute a group of metalloenzymes that oxidize a wide panel of natural compounds, such as galactose-containing saccharides or primary alcohols, into product derivatives exhibiting promising biotechnological interests. Despite a well-conserved first copper-coordination sphere and overall fold, some members of the AA5_2 subfamily are incapable of oxidizing galactose and galactosides but conversely efficiently catalyse the oxidation of diverse aliphatic alcohols. The objective of this study was to understand which residues dictate the substrate preferences between alcohol oxidases and galactose oxidases within the AA5_2 subfamily.

Tandem metalloenzymes gate plant cell entry by pathogenic fungi.

Global food security is endangered by fungal phytopathogens causing devastating crop production losses. Many of these pathogens use specialized appressoria cells to puncture plant cuticles. Here, we unveil a pair of alcohol oxidase-peroxidase enzymes to be essential for pathogenicity.

The Maize Pathogen Ustilago maydis Secretes Glycoside Hydrolases and Carbohydrate Oxidases Directed toward Components of the Fungal Cell Wall.

Filamentous fungi are keystone microorganisms in the regulation of many processes occurring on Earth, such as plant biomass decay and pathogenesis as well as symbiotic associations. In many of these processes, fungi secrete carbohydrate-active enzymes (CAZymes) to modify and/or degrade carbohydrates. Ten years ago, while evaluating the potential of a secretome from the maize pathogen Ustilago maydis to supplement lignocellulolytic cocktails, we noticed it contained many unknown or poorly characterized CAZymes.

A simple and direct ionic chromatography method to monitor galactose oxidase activity.

Galactose oxidase (GalOx, EC.1.1.

Activity-based protein profiling reveals dynamic substrate-specific cellulase secretion by saprotrophic basidiomycetes.

Background: Fungal saccharification of lignocellulosic biomass occurs concurrently with the secretion of a diverse collection of proteins, together functioning as a catalytic system to liberate soluble sugars from insoluble composite biomaterials. How different fungi respond to different substrates is of fundamental interest to the developing biomass saccharification industry. Among the cornerstones of fungal enzyme systems are the highly expressed cellulases (endo-β-glucanases and cellobiohydrolases).

The ectomycorrhizal basidiomycete Laccaria bicolor releases a GH28 polygalacturonase that plays a key role in symbiosis establishment.

In ectomycorrhiza, root penetration and colonization of the intercellular space by symbiotic hyphae is thought to rely on the mechanical force that results from hyphal tip growth, enhanced by the activity of secreted cell-wall-degrading enzymes. Here, we characterize the biochemical properties of the symbiosis-induced polygalacturonase LbGH28A from the ectomycorrhizal fungus Laccaria bicolor. The transcriptional regulation of LbGH28A was measured by quantitative PCR (qPCR).

A survey of substrate specificity among Auxiliary Activity Family 5 copper radical oxidases.

There is significant contemporary interest in the application of enzymes to replace or augment chemical reagents toward the development of more environmentally sound and sustainable processes. In particular, copper radical oxidases (CRO) from Auxiliary Activity Family 5 Subfamily 2 (AA5_2) are attractive, organic cofactor-free catalysts for the chemoselective oxidation of alcohols to the corresponding aldehydes. These enzymes were first defined by the archetypal galactose-6-oxidase (GalOx, EC 1.

Identification of Copper-Containing Oxidoreductases in the Secretomes of Three Species with a Focus on Copper Radical Oxidases for the Biocatalytic Production of Fatty Aldehydes.

Copper radical alcohol oxidases (CRO-AlcOx), which have been recently discovered among fungal phytopathogens, are attractive for the production of fragrant fatty aldehydes. With the initial objective to investigate the secretion of CRO-AlcOx by natural fungal strains, we undertook time course analyses of the secretomes of three Colletotrichum species (C. graminicola, C.

A Putative Lignin Copper Oxidase from .

The ability of , a fungus widely used for the commercial production of hemicellulases and cellulases, to grow and modify technical soda lignin was investigated. By quantifying fungal genomic DNA, showed growth and sporulation in solid and liquid cultures containing lignin alone. The analysis of released soluble lignin and residual insoluble lignin was indicative of enzymatic oxidative conversion of phenolic lignin side chains and the modification of lignin structure by cleaving the β-O-4 linkages.

Discovery of fungal oligosaccharide-oxidising flavo-enzymes with previously unknown substrates, redox-activity profiles and interplay with LPMOs.

Oxidative plant cell-wall processing enzymes are of great importance in biology and biotechnology. Yet, our insight into the functional interplay amongst such oxidative enzymes remains limited. Here, a phylogenetic analysis of the auxiliary activity 7 family (AA7), currently harbouring oligosaccharide flavo-oxidases, reveals a striking abundance of AA7-genes in phytopathogenic fungi and Oomycetes.

Identification of the molecular determinants driving the substrate specificity of fungal lytic polysaccharide monooxygenases (LPMOs).

Understanding enzymatic breakdown of plant biomass is crucial to develop nature-inspired biotechnological processes. Lytic polysaccharide monooxygenases (LPMOs) are microbial enzymes secreted by fungal saprotrophs involved in carbon recycling. LPMOs modify biomass by oxidatively cleaving polysaccharides, thereby enhancing the efficiency of glycoside hydrolases.

Evaluation of the Enzymatic Arsenal Secreted by During Growth on Sugarcane Bagasse With a Focus on LPMOs.

The high demand for energy and the increase of the greenhouse effect propel the necessity to develop new technologies to efficiently deconstruct the lignocellulosic materials into sugars monomers. Sugarcane bagasse is a rich polysaccharide residue from sugar and alcohol industries. The thermophilic fungus (syn.