Biomass enzymatic saccharification is determined by the non-KOH-extractable wall polymer features that predominately affect cellulose crystallinity in corn

• Published in: PloS one Vol. 9; no. 9; p. e108449
• Main Authors: Jia, Jun, Yu, Bin, Wu, Leiming, Wang, Hongwu, Wu, Zhiliang, Li, Ming, Huang, Pengyan, Feng, Shengqiu, Chen, Peng, Zheng, Yonglian, Peng, Liangcai
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 24.09.2014; Public Library of Science (PLoS)
• Subjects: Alcohol; Biodiesel fuels; Biofuels; Biology and Life Sciences; Biomass; Biopolymers - metabolism; Carbohydrate Metabolism; Carbohydrates; Cell walls; Cellulose; Cellulose - chemistry; Cellulose - metabolism; Comparative analysis; Corn; Correlation analysis; Crop residues; Crops; Crystal structure; Crystallinity; Crystallization; Digestibility; Engineering and Technology; Enzymes - metabolism; Ethanol; Feature extraction; Fermentation; G ratio; Genetic modification; Hexoses; Hydroxides - chemistry; Laboratories; Life sciences; Lignin; Lignocellulose; Measurement techniques; Miscanthus; Petroleum production; Plant sciences; Polymers; Potassium Compounds - chemistry; Residues; Saccharification; Sorghum; Sulfuric acid; Xylan; Zea mays; Zea mays - metabolism
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0108449

Corn is a major food crop with enormous biomass residues for biofuel production. Due to cell wall recalcitrance, it becomes essential to identify the key factors of lignocellulose on biomass saccharification. In this study, we examined total 40 corn accessions that displayed a diverse cell wall composition. Correlation analysis showed that cellulose and lignin levels negatively affected biomass digestibility after NaOH pretreatments at p<0.05 & 0.01, but hemicelluloses did not show any significant impact on hexoses yields. Comparative analysis of five standard pairs of corn samples indicated that cellulose and lignin should not be the major factors on biomass saccharification after pretreatments with NaOH and H2SO4 at three concentrations. Notably, despite that the non-KOH-extractable residues covered 12%-23% hemicelluloses and lignin of total biomass, their wall polymer features exhibited the predominant effects on biomass enzymatic hydrolysis including Ara substitution degree of xylan (reverse Xyl/Ara) and S/G ratio of lignin. Furthermore, the non-KOH-extractable polymer features could significantly affect lignocellulose crystallinity at p<0.05, leading to a high biomass digestibility. Hence, this study could suggest an optimal approach for genetic modification of plant cell walls in bioenergy corn.