For SSF3 process, both alpha-amylase (Spezyme Alpha) at 3,532 AAU/kg CF and beta-glucanase (Optimash TBG) at 2,812 U/kg CF were added for liquefaction. For SSF, besides using glucoamylase (Distillase ASP) at 540 GAU/kg CF, additional glucoamylase (Amigase Mega L) at 0.035% w/w was added to improve the efficacy of hydrolyzing residual starch in the slurry.