Clostridium thermocellum 27405 is a potential consolidated bioprocessing (CBP) strain due to the efficient lignocellulose degradation ability. Here, the spent mushroom substrate (SMS), a lignocellulosic byproduct of agriculture, was used as a substrate for hydrogen production by C. thermocellum. SMS showed a good performance for hydrogen production and the hydrogen production was significantly enhanced by C. thermocellum supplemented with beta-glucosidases, with the highest production reaching 56.0 mM, an increase of 37%. Additionally, beta-glucosidase and Triton X-100 had a synergistic effect on biological saccharification, resulted in an accumulation of 5.06 g/L reducing sugars, an increase of 28%. However, fusion beta-glucosidase showed no improvement on hydrogen production and biological saccharification. The present study demonstrates the different influences of beta-glucosidase and fusion beta-glucosidase on hydrogen production and biological saccharification in CBP system and provides valuable information on the biodegradation of SMS using C. thermocellum. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.