CAZyme prediction in ascomycetous yeast genomes guides discovery of novel xylanolytic species with diverse capacities for hemicellulose hydrolysis

Abstract Background Ascomycetous yeasts from the kingdom fungi inhabit every biome in nature. While filamentous have been studied extensively regarding their enzymatic degradation of complex polymers comprising lignocellulose, largely overlooked. As are key organisms used industry, understanding strategies for biomass conversion is an important factor developing new and more efficient cell factories. The aim this study was to identify polysaccharide-degrading by mining CAZymes 332 yeast genomes phylum Ascomycota. Selected CAZyme-rich were then characterized detail through growth activity assays. Results CAZyme analysis revealed a large spread number CAZyme-encoding genes ascomycetous genomes. We identified total 217 predicted families, including several likely involved plant polysaccharides. Growth characterization 40 no cellulolytic yeasts, but species Trichomonascaceae CUG-Ser1 clades able grow on xylan, mixed-linkage β-glucan xyloglucan. Blastobotrys mokoenaii, Sugiyamaella lignohabitans , Spencermartinsiella europaea Scheffersomyces displayed superior xylan well as high activities. These possess putative xylanolytic enzymes, ones well-studied xylanase-containing glycoside hydrolase families GH10 GH30, which appear be attached surface. B. mokoenaii only containing GH11 xylanase, shown secreted. Surprisingly, known xylanases Wickerhamomyces canadensis suggesting that possesses novel xylanases. In addition, examining non-sequenced closely related we with capacities. Conclusions Our approach combining high-throughput bioinformatic CAZyme-prediction enzyme proved powerful pipeline discovery xylan-degrading enzymes. display diverse profiles terms growth, activities substrate preferences, pointing towards different utilization xylan. Together, results provide insights into how degrade can improve factory design industrial bioconversion processes.