| 摘要: |
| 采用纤维素复合酶直接酶解(Direct enzymolysis,DE)、1% H2SO4预处理后酶解(Enzymolysis after 1% H2SO4 pretreatment,ACE)和1% NaOH预处理后酶解(Enzymolysis after 1% NaOH pretreatment,ALE)3种处理方法对2种生态型柳枝稷Alamo(低地型)和Cave-in-Rock(高地型)茎秆进行降解效率的研究,并对其细胞壁组成特点进行分析。结果表明:1)DE处理下,Alamo茎秆总产糖效率、六碳糖产糖效率和纤维素降解效率分别显著高于Cave-in-Rock 24.94%、40.52%和24.68%(P<0.05或0.01);ACE处理下,Alamo茎秆预处理产糖效率、酶解产糖效率和总产糖效率分别显著高于Cave-in-Rock 17.13%、25.69%和16.87%,五碳糖产糖效率、六碳糖产糖效率和纤维素降解效率分别显著高于Cave-in-Rock 9.71%、38.93%和21.86%;ALE处理下,Alamo茎秆酶解产糖效率和总产糖效率分别显著高于Cave-in-Rock 16.69%和13.48%,五碳糖产糖效率、六碳糖产糖效率和纤维素降解效率分别显著高于Cave-in-Rock 13.07%、17.46%和6.59%;2)Alamo茎秆细胞壁中纤维素含量显著高于Cave-in-Rock 11.31%,纤维素结晶度和聚合度分别显著低10.09%和40.54%;半纤维素中阿拉伯糖(Ara)含量显著高于Cave-in-Rock 5.28%,而木糖(Xyl)含量显著低于Cave-in-Rock 1.37%,阿拉伯糖替代程度(Ara/Xyl)显著高于Cave-in-Rock 6.74%;木质素单体紫丁香基(S)含量显著高于Cave-in-Rock 16.40%。较高的纤维素含量、较低的纤维素结晶度和聚合度是Alamo茎秆高产糖效率的直接原因,推测阿拉伯糖的替代程度对纤维素结晶度和聚合度的影响以及较高含量的木质素单体S可能是Alamo茎秆高降解效率的深层次原因。 |
| 关键词: 柳枝稷 生态型 茎秆 细胞壁 降解效率 |
| DOI：10.11841/j.issn.1007-4333.2015.02.005 |
| 投稿时间：2014-07-01 |
| 基金项目:国家自然科学基金(31101103); 北京市科技新星计划(Z131105000413020); 北京市农林科学院青年科研基金(QNJJ201219) |
|
| Difference of stem cell wall compositional characteristics and degradation efficiency in different genotypes of switchgrass |
|
ZHAO Chun-qiao1,2, FAN Xi-feng2, HOU Xin-cun2, WU Jü-ying2, HU Yue-gao1, ZHU Yi2, YUE Yue-sen2
|
| (1.College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China;2.Research & Development Center for Grass and Environment, Beijing Academy of Agricultural andForestry Sciences, Beijing 100097, China) |
| Abstract: |
| Direct enzymolysis (DE), enzymolysis after 1% H2SO4 pretreatment (ACE) and 1% NaOH pretreatment (ALE) by mixed-cellulases was conducted to determine the degradation efficiency of Alamo (lowland) and Cave-in-Rock (upland) stem.Afterwards the cell wall compositional characteristics of stem was analysed in particular.1)Under the disposal of DE, total sugar yield efficiency, hexose yield efficiency and cellulose degradation efficiency of Alamo stem was 24.94%, 40.52% and 24.68% higher than Cave-in-Rock values, respectively.Under the disposal of ACE, sugar yield efficiency released from pretreatment, sugar yield efficiency released from enzymolysis and total sugar yield efficiency was 17.13%, 25.69% and 16.87% higher than those obtained from Cave-in-Rock, respectively.What is more, the pentose yield efficiency, hexose yield efficiency and cellulose degradation efficiency was 9.71%, 38.93% and 21.86% higher than those of Cave-in-Rock.Under the disposal of ALE, sugar yield efficiency released from enzymolysis and total sugar yield efficiency was 16.69% and 13.48% higher than those from Cave-in-Rock and the pentose yield efficiency, hexose yield efficiency and cellulose degradation efficiency was 13.07%, 17.46% and 6.59% higher than Cave-in-Rock values, respectively.All these differences were statistically significant (P<0.05 or 0.01).2)Content of cellulose of Alamo stem was 11.31% significantly higher than that from Cave-in-Rock, whereas the cellulose crystallinity indexes and degree of polymerization was 10.09% and 40.54% significantly lower than those from Cave-in-Rock, respectively.Content of arabinose(Ara) of hemicellulose in Alamo stem was 5.28% significantly higher than in Cave-in-Rock.However the content of Xylose(Xyl) was 1.37% lower than in Cave-in-Rock.The degree of Ara substitution in hemicellulose (Ara/Xyl) of Alamo stem was 6.74% significantly higher than in Cave-in-Rock.Syringyl (S) monomer units were 16.40% significantly higher than in Cave-in-Rock.Taken together, higher cellulose content, lower cellulose crystallinity indexes and degree of polymerization are the major factors rendering the higher degradation efficiency of Alamo stem.Influence of Ara on branch structure of hemicellulose which negatively affects cellulose crystallinity indexes and degree of polymerization as well as S monomer units might be the key factors rendering higher degradation efficiency of Alamo stem. |
| Key words: switchgrass ecotype stem cell wall degradation efficiency |
