Characterization Of Cellulose Structures For Biomass Degradation In Energy Crops

Energy crisis and globe warming have led to an intensive demand for renewable and sustainable fuels. Currently, lignocelluloses biomass is considered for conversion to liquid fuels. However, biomass conversion is still under developing because of its recalcitrance. Despite that a great effort has been made to increase the lignocelluloses conversion rate, the difficulty remains with two crucial factors:biomass pretreatment and enzymatic degradation. It is determined by properties of the cellulose crystallinity and lignin intercross linking. Therefore, understanding of plant cell wall structure and its effects on biomass conversion is scientifically important for developing biofuels in the near future.In terms of the experiments, I initially collected several typical energy crops including 6 miscanthus germplasm and 3 brittle culm mutants of maize. Analyzed their enzymatic degradation after 0.25%(v/v)H2SO4 and 0.5%(w/w)NaOH pretreatments.The results indicated that enzymatic sugar release from H2SO4 treated miscanthus was higher than NaOH treated. And there were significant differences among these materials, from 8% to 18%.The cellulose structural features were characterized as DP value, molecule number and crystallinity. The DP of crude cellulose was 5-10 time more than the crystal cellulose, and the molecule number of crystal cellulose was 5-10 time more than the crude cellulose. It means the cellulose is constructed by a series of crystal sections and amorphous sections. The results also showed that the sugar yields released by enzymatic hydrolysis were closely correlated with the cellulose content, DP value and mole number of cellulose. A significantly negative correlation was tested between cellulose crystallinity and its degradation efficiency. Thus, it was concluded that the DP and mole number of cellulose can determine the composition and property of plant cell walls to some degree.