液氨预处理强化复合菌系WSC-6降解稻秆的性能

高效、经济的预处理技术对提高稻秆的生物降解效率，实现稻秆资源的工业化利用具有重要意义。为确定液氨对稻秆生物降解性的影响，以复合菌系WSC-接种液氨预处理的稻秆，研究其生物降解性能。结果表明，用液氨预处理后的稻秆作为碳源，由于营养结构的改变，复合菌系WSC-6需要经过3d的适应期进入对数增长期，氮源利用率和微生物浓度均显著高于未处理的对照组。复合菌系WSC-6对其生物降解性得到明显提高，7d后的稻秆失重率达到62．7％，纤维素、半纤维素和木质素的降解率分别达到57．5％、85．6％和36．3％。液氨预处理对发酵系统的pH值影响不大，复合菌系WSC-对稻秆降解的pH值仍维持在6．5～8．6之间，有利于进行丁酸型发酵，这对后续利用乙酸高效生产沼气具有重要意义。

Biodegradability of rice straw pretreated by liquid ammonia enhanced with the composite strains WSC-6

Efficient and economic pretreatment is an important way to improve the biodegradation efficiency of rice straw and achieve the biogas industrialization production. To evaluate the effect of liquid ammonia on the biodegradation of rice straw, the pretreated rice straw was inoculated with the composite strains WSC-6 and its bioconversion efficiency in the methane production was investigated over a 7-day period. Results indicated that u- sing the rice straw of ammonia pretreated as carbon source, nitrogen utilization and the concentration of the com- posite strains WSC-6 were significantly higher than the unpretreated group regardless of three days adjustment phase of the composite strains WSC-6. The higher biodegradation efficiency （62.7%） of the pretreated rice straw was achieved, and biodegradation rates of cellulose, hemicellulose and lignin were 57.5% ,85.6% and 36.3% , respectively. The ambient pH was maintained between 6.5 and 8.6, which is essential to form butyric acid-type fermentation. This could be significant to subsequent methane production via the acetic acid route.