Catalyzes the hydrolysis of alpha,alpha-trehalose into two molecules of D-glucose. alpha,alpha-trehalose + H2O = alpha-D-glucose + beta-D-glucose kcat is 77.0 sec(-1) at 50 degrees Celsius and pH 4.0. kcat is 102.5 sec(-1) at 60 degrees Celsius and pH 4.0. Optimum pH is 4.0 (PubMed:29574614, PubMed:29642287). More than half of the maximal activity is observed over a range between pH 3.3 and 4.0 (PubMed:29574614). Optimum temperature is 60 degrees Celsius. Glycan degradation; trehalose degradation; D-glucose from alpha,alpha-trehalose: step 1/1. Belongs to the glycosyl hydrolase 15 family.