Hydrolyzes trehalose to glucose. Could be involved, in cells returning to low osmolarity conditions, in the utilization of the accumulated cytoplasmic trehalose, which was synthesized in response to high osmolarity. alpha,alpha-trehalose + H2O = alpha-D-glucose + beta-D-glucose Activity decreases with increasing salt concentrations. Optimum pH is 6.0. Glycan degradation; trehalose degradation; D-glucose from alpha,alpha-trehalose: step 1/1. Monomer. Weakly induced by high osmolarity but not by trehalose. Expression is partially dependent on RpoS. Belongs to the glycosyl hydrolase 37 family.