As the main decomposers and recyclers in nature, fungi secrete complex mixtures of extracellular enzymes for degradation of plant biomass, which is essential for mobilization of the organic carbon fixed by the photosynthesis in vegetal cells. Biotechnology can emulate the closed natural biological cycles, using lignocellulosic biomass as a renewable resource and lignocellulolytic fungal enzymes as catalysts to sustainably produce consumer goods. Cellulose and hemicellulose are the major polysaccharides on Earth, and the main enzymes involved in their hydrolytic depolymerization are cellulases (endoglucanases, cellobiohydrolases, and β-glucosidases) and hemicellulases (mainly endoxylanases and β-xylosidases). This work will focus on the enzymes secreted by the filamentous ascomycete Talaromyces amestolkiae and on some of their biotechnological applications. Their excellent hydrolytic activity was demonstrated by the partial degradation of xylans to prebiotic oligosaccharides by the endoxylanase XynN, or by the saccharification of lignocellulosic wastes to monosaccharides (fermentable to ethanol) either by the whole secretomes or by isolated enzymes used as supplements of commercial cocktails. However, apart from their expected hydrolytic activity, some of the β-glycosidases produced by this strain catalyze the transfer of a sugar molecule to specific aglycons by transglycosylation. As the synthesis of customized glycoconjugates is a major goal for biocatalysis, mutant variants of the β-xyloxidase BxTW1 and the ß-glucosidases BGL-1 and BGL-2 were obtained by directed mutagenesis, substantially improving the regioselective production yields of bioactive glycosides since they showed reduced or null hydrolytic activity.

作为自然界中的主要分解者和回收者，真菌分泌复杂的细胞外酶混合物来降解植物生物质，这对于植物细胞中通过光合作用固定的有机碳的动员至关重要。生物技术可以模拟封闭的自然生物循环，使用木质纤维素生物质作为可再生资源，使用木质纤维素分解真菌酶作为催化剂，以可持续地生产消费品。纤维素和半纤维素是地球上的主要多糖，参与其水解解聚的主要酶是纤维素酶（内切葡聚糖酶、纤维二糖水解酶和β-葡糖苷酶）和半纤维素酶（主要是内切木聚糖酶和β-木糖苷酶）。这项工作将集中在丝状子囊菌Talaromyces amestolkiae分泌的酶上以及他们的一些生物技术应用。通过木聚糖内切酶 XynN 将木聚糖部分降解为益生元寡糖，或通过整个分泌组或用作商业鸡尾酒补充剂的分离酶将木质纤维素废物糖化为单糖（可发酵为乙醇），证明了它们具有出色的水解活性。然而，除了它们预期的水解活性之外，该菌株产生的一些 β-糖苷酶催化糖分子通过转糖基转移到特定的苷元。由于定制糖缀合物的合成是生物催化的主要目标，因此通过定向诱变获得了 β-木氧化酶 BxTW1 和 β-葡萄糖苷酶 BGL-1 和 BGL-2 的突变变体，