高效稳定纤维素分解混合菌群的筛选及分解特性研究

以高纤维素素含量的土壤为筛选源,利用定向筛选技术,经过多代淘汰,最终筛选出一组木质纤维素分解混合菌群P-C。混合菌群的生长曲线没有明显的分界线,在培养4至5天时,出现了短暂的平稳期,在培养第7天时出现峰值,此时混合菌群的纤维素酶活最高。以天然纤维素为产酶碳源时,混合菌群纤维素酶活明显高于以人工纤维素为产酶碳源时的酶活,以秸秆为碳源时的纤维素酶活是以滤纸为碳源时的1.5倍。混合菌群纤维素酶的最适pH是6,最适酶促反应温度是45℃,但在35℃-40℃时也具有较高酶活。pH=6,糖化48 h时,发酵液糖浓度最高。     

Fenton试剂+SBR法处理纤维素废水的研究

采用Fenton试剂+SBR法对COD很高的纤维素废水进行处理。首先用絮凝法预处理纤维素废水,然后加入Fenton试剂进行处理,得出在pH为3、Fe2+用量为1.5×10-2 mol/L即2.28 g/L、H2O2的投加量为0.858 g/L、H2O2和Fe2+的投加量比为6、反应时间为4 h时效果最佳,COD降到1 002.8 mg/L,去除效率为88.3%。然后进行SBR生物处理,厌氧处理8 h,好样处理10 h,此时COD处理效果最好为92.8 mg/L,去除效率为90.7%,BOD5为46.8 mg/L,去除效率为88.3%。     

生物质能源干式厌氧发酵预处理的研究进展

秸秆干式厌氧发酵以农作物秸秆为原料,在较小的规模和较少资本投入的条件下,产生可以循环使用的生物质能。通过物理法、化学法、物理化学法、生物法等预处理方法,可使后续发酵效率大大提高。本文论述了国内外生物质秸秆预处理技术的研究现状,对各种预处理方法的优缺点进行了分析与讨论．并对生物质秸秆预处理技术用于厌氧发酵的前景进行了展望。     

Characterization of the e ective cellulose degrading strain CTL-6

An e cient cellulose degrading bacteria exists in the thermophilic wheat straw-degrading community, WDC2. However, this strain cannot be isolated and cultured using conventional separation techniques under strict anaerobic conditions. We successfully isolated a strain of e ective cellulose degrading bacteria CTL-6 using a wash, heat shock, and solid-liquid alternating process. Analysis of its properties revealed that, although the community containing the strain CTL-6 grew under aerobic conditions, the purified strain CTL-6 only grew under anaerobic culture conditions. The strain CTL-6 had a striking capability of degrading cellulose (80.9% weight loss after 9 days of culture). The highest e ciency value of the endocellulase (CMCase activity) was 0.404 mol/(min mL), cellulose degradation e ciency by CTL-6 was remarkably high at 50–65°C with the highest degradation e ciency observed at 60°C. The 16S rRNA gene sequence analysis indicated that the closest relative to strain CTL-6 belonged to the genus Clostridium thermocellum. Strain CTL-6 was capable of utilizing cellulose, cellobiose, and glucose. Strain CTL-6 also grew with Sorbitol as the sole carbon source, whereas C. thermocellum is unable to do so.