厌氧分解木质纤维素水解残渣中难降解性糖类研究

摘要

There is a general problem of incomplete hydrolysis of cellulose in lignocellulose,and these refractory carbohydrates are present in un-hydrolyzed residues,leading to the decrease in sugar recovery and carbohydrate utilization.In this work,anaerobic microorganism was used to decompose the refractory carbohydrates in un-hydrolyzed residue,and then were converted into biogas.The effects of temperatures and inoculum ratios on anaerobic degradation of refractory carbohydrates were investigated.The results indicated that the content of polysaccharides in residue were significantly reduced after anaerobic degradation.The polysaccharides contents were decreased with the increasing of inoculums ratio,while the degradation rates were increased.The degradation rates under high temperature were higher than that under moderate temperature.With the optimized condition,the glucan and xylose contents were reduced to 4％ and 1％ respectively after anaerobic digestion,and the cumulative methane production of treated residue was up to 184.70 mL · g-1VS.The results demonstrated that the refractory carbohydrates in un-hydrolyzed residue could be anaerobically degraded,providing more carbohydrates recovering from lignocelluloses degradation.%木质纤维素的生物炼制普遍存在纤维素水解不完全的问题.难降解性糖类大量存在于水解残渣中,既降低了纤维素的糖得率,也影响了水解残渣的回收利用.文章利用厌氧微生物来分解水解残渣中的难降解性糖类并将其转化为沼气,研究了不同温度和接种比例条件下难降解性糖类的厌氧降解性能.结果显示,厌氧消化后水解残渣中聚糖含量显著降低;厌氧分解后的聚糖含量随接种比例的增大而降低,聚糖降解率随接种比例的增大而升高,高温条件下的降解程度高于中温条件.优化条件下,厌氧分解后葡聚糖和木聚糖含量分别降低至4％和1％左右,水解残渣的累积甲烷产量可达184.70 mL·g-1VS.研究结果证实了厌氧分解水解残渣中难降解性糖类的可行性,为木质纤维素生物炼制过程水解残渣的回收利用提供了新的途径.