Native lignocellulosic biomass has limited accessibility to enzymes and microorganisms due to its complex cell wall structure of cellulose-hemicellulose-lignin. Therefore

pretreatment is a prerequisite to overcome recalcitrance of biomass and enhance bio-chemical conversion ratio of polysaccharides. Compared with other methods

high temperature liquid hot water pretreatment has the advantages of no chemical addition and less inhibitory products. In the present study

different structural changes at plant tissue

cellular

and cell wall levels were investigated to understand the decomposition mechanism of sugarcane bagasse cell wall in the liquid hot water pretreatment. Transmission electron microscopy (TEM) images showed that sugarcane bagasse cell walls were composed of middle lamella (ML) layers

primary wall (P) layers

and secondary wall layers (S). While after the pretreatment

the boundaries among the ML

P and S layers of treated samples could not be distinguished exactly. The data from scanning electron microscopy and energy dispersive X-ray analysis(SEM-EDXA)showed that migration of lignin happened among different cell wall layers. Moreover

pseudo-lignin

the degradation products of lignin and xylan

appeared on the surface of pretreated sugarcane bagasse. Furthermore

Raman spectra of treated sugarcane bagasse indicated that distribution of cellulose in the cell wall was homogenized

and the difference in chemical composition was reduced.