Thomas Vanessa A, Kothari Ninad, Bhagia Samarthya, Akinosho Hannah, Li Mi, Pu Yunqiao, Yoo Chang Geun, Pattathil Sivakumar, Hahn Michael G, Raguaskas Arthur J, Wyman Charles E, Kumar Rajeev
Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California Riverside, Riverside, CA 92507 USA.
Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California Riverside, Riverside, CA 92507 USA.
Biotechnol Biofuels. 2017 Nov 30;10:292. doi: 10.1186/s13068-017-0975-x. eCollection 2017.
natural variants have been shown to realize a broad range of sugar yields during saccharification, however, the structural features responsible for higher sugar release from natural variants are not clear. In addition, the sugar release patterns resulting from digestion with two distinct biological systems, fungal enzymes and , have yet to be evaluated and compared. This study evaluates the effect of structural features of three natural variant lines, which includes the line BESC standard, with respect to the overall process of sugar release for two different biological systems.
natural variants, SKWE 24-2 and BESC 876, showed higher sugar release from hydrothermal pretreatment combined with either enzymatic hydrolysis or fermentation compared to the natural variant, BESC standard. However, outperformed the fungal cellulases yielding 96.0, 95.5, and 85.9% glucan plus xylan release from SKWE 24-2, BESC 876, and BESC standard, respectively. Among the feedstock properties evaluated, cellulose accessibility and glycome profiling provided insights into factors that govern differences in sugar release between the low recalcitrant lines and the BESC standard line. However, because this distinction was more apparent in the solids after pretreatment than in the untreated biomass, pretreatment was necessary to differentiate recalcitrance among lines. Glycome profiling analysis showed that SKWE 24-2 contained the most loosely bound cell wall glycans, followed by BESC 876, and BESC standard. Additionally, lower molecular weight lignin may be favorable for effective hydrolysis, since reduced lignin molecular weight more than fungal enzymes across all lines.
Low recalcitrant natural variants, SKWE 24-2 and BESC 876, showed higher sugar yields than BESC standard when hydrothermal pretreatment was combined with biological digestion. However, was determined to be a more robust and effective biological catalyst than a commercial fungal cellulase cocktail. As anticipated, recalcitrance was not readily predicted through analytical methods that determined structural properties alone. However, combining structural analysis with pretreatment enabled the identification of attributes that govern recalcitrance, namely cellulose accessibility, xylan content in the pretreated solids, and non-cellulosic glycan extractability.
已表明天然变体在糖化过程中可实现广泛的糖产量，然而，导致天然变体释放更多糖的结构特征尚不清楚。此外，由两种不同生物系统（真菌酶和[此处原文缺失一种生物系统名称]）消化产生的糖释放模式尚未得到评估和比较。本研究评估了三个天然变体品系的结构特征对两种不同生物系统糖释放全过程的影响，其中包括BESC标准品系。
与天然变体BESC标准品系相比，天然变体SKWE 24 - 2和BESC 876在水热预处理结合酶水解或[此处原文缺失一种发酵方式名称]发酵时表现出更高的糖释放量。然而，[此处原文缺失一种生物系统名称]比真菌纤维素酶更有效，从SKWE 24 - 2、BESC 876和BESC标准品系中分别释放出96.0%、95.5%和85.9%的葡聚糖加木聚糖。在所评估的原料特性中，纤维素可及性和聚糖谱分析为低抗性品系与BESC标准品系之间糖释放差异的影响因素提供了见解。然而，由于这种差异在预处理后的固体中比在未处理的生物质中更明显，因此需要进行预处理以区分各品系之间的抗性。聚糖谱分析表明，SKWE 24 - 2含有结合最松散的细胞壁聚糖，其次是BESC 876和BESC标准品系。此外，较低分子量的木质素可能有利于有效水解，因为在所有品系中，[此处原文缺失一种生物系统名称]降低木质素分子量的效果超过真菌酶。
低抗性天然变体SKWE 24 - 2和BESC 876在水热预处理与生物消化相结合时，糖产量高于BESC标准品系。然而，[此处原文缺失一种生物系统名称]被确定为比商业真菌纤维素酶混合物更强大、更有效的生物催化剂。正如预期的那样，仅通过确定结构特性的分析方法不容易预测抗性。然而，将结构分析与预处理相结合能够识别出控制抗性的属性，即纤维素可及性、预处理固体中的木聚糖含量以及非纤维素聚糖的可提取性。
