(90f) Change of the Structure of Sweet Sorghum Bagasse After Solid-Fermentation

Solid–fermentation technology of sweet sorghum is an efficient, simple and low cost process to produce ethanol. In this study, the structure of sweet sorghum bagasse before and after solid-fermatation was determined by analysis of composition, IR, SEM and XRD. The results indicated that the sweet sorghum bagasse after solid-fermentation (SSBA) has lower crystallized cellulose (15.87%), higher amorphouse cellulose (3.69%) and significantly higher xylan (23.32%) than the sweet sorghum bagasse before solid-fermentation (SSBB). And the corresponding composition of SSBB was 22.41%, 3.39% and 14.44% respectively. Moreover, the crysrallinity index and degree of polymerization (DP) of SSBA was also slightly lower than that of SSBB. The image obtain from SEM indicated the surface of SSBA was rougher than that of SSBB. This means yeast destruct the cell wall of sweet sorghum stem to some extent. It is interesting that the compostion of lignin of sweet sorghum also changed significantly after solid-fermentation. Total lignin increased after solid-fermatation, while the ratio of S and H unit of lignin decreased. All results revealed that yeast not only utilized the soluble sugars in sweet sorghum stem, but also metabolized some composition of cell wall. So this sweet sorghum bagasse with relative higher xylan could be a potential feedstock for xylose or furfural. It is also a potential feedstock for lignocellulosic ethanol due to its relative feasibly accessible structure.