Impact of lignin polymer backbone esters on ionic liquid pretreatment of poplar

Biotechnology for Biofuels

卷:10

Seema Singh¹  Kwang Ho Kim¹  Blake A. Simmons¹  Tanmoy Dutta¹  John Ralph²  Shawn D. Mansfield³ 

[1] Deconstruction Division, Joint BioEnergy Institute;

[2] Department of Biochemistry, University of Wisconsin;

[3] Department of Energy Great Lakes Bioenergy Research Center, Wisconsin Energy Institute;

关键词: Biofuels;    Biomass;    Lignocellulose;   

DOI  :  10.1186/s13068-017-0784-2

来源: DOAJ

【 摘 要 】

Abstract Background Biomass pretreatment remains an essential step in lignocellulosic biofuel production, largely to facilitate the efficient removal of lignin and increase enzyme accessibility to the polysaccharides. In recent years, there have been significant efforts in planta to reduce lignin content or modify its composition to overcome the inherent recalcitrance that it imposes on lignocellulosic biomass during processing. Here, transgenic poplar lines in which monolignol ferulate conjugates were synthesized during cell wall development to introduce, during lignification, readily cleavable ester linkages into the lignin polymer backbone (i.e., “zip lignin”), along with wild-type (WT) controls, were pretreated with different ionic liquids (ILs). Results The strategic introduction of ester bonds into the lignin backbone resulted in increased pretreatment efficiency and released more carbohydrates with lower energy input. After pretreatment with any of three different ILs, and after limited saccharification, the transgenic poplars, especially those with relatively higher amounts of incorporated monolignol ferulate conjugates, yielded up to 23% higher sugar levels compared to WT plants. Conclusion Our findings clearly demonstrate that the introduction of ester linkages into the lignin polymer backbone decreases biomass recalcitrance in poplar has the potential to reduce the energy and/or amount of IL required for effective pretreatment, and could enable the development of an economically viable and sustainable biorefinery process.

【 授权许可】

Unknown