Fig. 4

Alkali-pretreated sweet sorghum straw (transverse section, 20 µm in thickness) imaged in real time during enzymatic hydrolysis at room temperature (enzyme loading: 9 IU/g substrate). Image a–f were recorded with time intervals of 60 min using bright-field light microscopy. Pc parenchyma cells, VB vascular bundles, Sc sclerenchyma cells, St sieve tube. Scale bars: 50 µm