Trichoderma reesei host cells expressing a glucoamylase from Aspergillus fumigatus and methods of use thereof

摘要

Fungal glucoamylases from Aspergillus fumigatus—expressed in Trichoderma reesei host cells (AfGATR) are provided. Trichoderma reesei host cells express AfGATRs at higher, or at least comparable, levels to natively expressed AfGA Aspergillus fumigatus. AfGATRs, including AfGA1TR and AfGA2TR, exhibit high activity at elevated temperatures and at low pH, so AfGATRs can be used efficiently in a process of saccharification in the presence of alpha-amylase, such as Aspergillus kawachii alpha-amylase (AkAA). AfGATRs advantageously catalyze starch saccharification to an oligosaccharide composition significantly enriched in DP1 (i.e., glucose) compared to the products of saccharification catalyzed by Aspergillus niger glucoamylase (AnGA) or native AfGA expressed in Aspergillus fumigatus. AfGATRs such as AfGA1TR, AfGA2TR or a variant thereof can be used at a lower dosage than AnGA and natively expressed AfGAs to produce comparable levels of glucose.