【摘要】 为了探明WSC-6分解稻秆过程中的代谢特性,本试验以稻杆为唯一碳源,50℃静止培养WSC-6,以一次性添加不同量稻秆和多次连续添加的方式,研究了WSC-6分解稻杆的相对分解率、绝对分解量、分解产物及pH变化特性.结果表明,一次性添加1%稻秆时,pH由初始的7.8迅速下降,第3 d降到6.0后逐渐回升,6 d后稳定在8.0左右,在此过程中DO值保持在0.01~0.12 mg.L-1微好氧条件.以GC-MS法在稻杆分解过程中检测到乙醇、乙酸、乳酸、甘油等10种以上有机物,其中乳酸的含量最高,为7.381 g.L-1.在90 d的实验中,一次性添加不同量稻秆时,随着稻秆量的增加,pH下降得快而低,且回升时间拖后,当稻秆量为5%时pH下降到5.0后不再回升.在多次连续添加稻秆的实验中,隔12d和15d添加的处理pH重复下降和回升的规律性变化,分解活性保持旺盛.90 d后隔15 d添加的处理相对分解率最高,为86.7%;绝对分解量以隔6 d添加的处理最高,为32.4 g.pH变化规律能够反映WSC-6对木质纤维素的分解进程及分解活性.更多还原

【Abstract】 To detect the metabolic characteristic of rice straw degradation by composite microbial system WSC-6,we cultured WSC-6 in the media used rice straw as the limiting carbon source.The rice straw was added in the style of different quantity once or the same quantity at the different time intervals during 90 days culture.The systems were cultivated under static condition at 50℃.The degradation ratio,absolute degradation quantity,products from degradation and dynamics of pH value of fermentation system were all investigated.The results showed: when 1% rice straw was added once,the pH of fermentation system decreased from initial 7.8 to 6.0 within the first three days inoculation,and after six-day cultivation,it increased to 8.0 and was stable.For dissolved oxygen concentration（DO）,the value was maintained at range of 0.01 to 0.12(mg·L^-1) of microaerobic condition.During the rice straw degradation,more than ten kinds of products including ethanol,acetic acid,lactic acid and glycerol and so on were detected using GC-MS.Especially,the highest concentration of lactic acid among all products was 7.381(g·L^-1) at 24 h after inoculation.During 90-day cultivation,for the addition treatments of the different quantity once,the more rice straw added,the quicker and lower the pH decreased,and the longer time intervals returned the pHs were.Especially for 5.0% addition,when 5.0% of rice straw was added once,pH did not increase again after it decreased. Among the addition of the same quantity at the different time intervals,the trend of decrease-increase in pH at 12-day and 15-day intervals could be repeated and high degradation activity well maintained.After 90-day of inoculation,the highest degradation ratio occurred in the treatment at 15-day interval,which was 86.7%.The highest absolute quantity occurred in the treatment at 6-day interval,which was 32.4 g.The trend of pH changes can indicate the activity of lignocellulose degradation and degradation process of the WSC-6.更多还原