Center for Structural Molecular Biology and Molecular Bioscience and Biotechnology Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Biomacromolecules. 2010 Sep 13;11(9):2329-35. doi: 10.1021/bm100455h.
The generation of bioethanol from lignocellulosic biomass holds great promise for renewable and clean energy production. A better understanding of the complex mechanisms of lignocellulose breakdown during various pretreatment methods is needed to realize this potential in a cost and energy efficient way. Here we use small-angle neutron scattering (SANS) to characterize morphological changes in switchgrass lignocellulose across molecular to submicrometer length scales resulting from the industrially relevant dilute acid pretreatment method. Our results demonstrate that dilute acid pretreatment increases the cross-sectional radius of the crystalline cellulose fibril. This change is accompanied by removal of hemicellulose and the formation of R(g) ∼ 135 A lignin aggregates. The structural signature of smooth cell wall surfaces is observed at length scales larger than 1000 A, and it remains remarkably invariable during pretreatment. This study elucidates the interplay of the different biomolecular components in the breakdown process of switchgrass by dilute acid pretreatment. The results are important for the development of efficient strategies of biomass to biofuel conversion.
从木质纤维素生物质生产生物乙醇具有很大的可再生和清洁能源生产的潜力。为了以成本和能源有效的方式实现这一潜力，需要更好地了解木质纤维素在各种预处理方法下分解的复杂机制。在这里，我们使用小角中子散射（SANS）来表征柳枝稷木质纤维素在工业相关的稀酸预处理方法下，从分子到亚微米长度尺度的形态变化。我们的结果表明，稀酸预处理会增加结晶纤维素原纤维的横截面半径。这种变化伴随着半纤维素的去除和 R(g)∼135Å 木质素聚集体的形成。在大于 1000Å 的长度尺度上观察到光滑细胞壁表面的结构特征，并且在预处理过程中仍然非常不变。这项研究阐明了稀酸预处理过程中不同生物分子成分的相互作用。这些结果对于开发有效的生物质到生物燃料转化策略非常重要。
