Fig. 4From: Optimization of production conditions for β-mannanase using apple pomace as raw material in solid-state fermentationResponse surface plot for the activity of β-mannanase in terms of the effects of a (NH4)2SO4 and KH2PO4, b (NH4)2SO4 and initial moisture, and c KH2PO4 and initial moisture. Factors not included in the axes were fixed at their respective optimum levelsBack to article page