Fuel from plant cell walls: recent developments in second generation bioethanol research

Abstract

As bioethanol from sugarcane and wheat falls out of favour due to concerns about food security, research is ongoing into genetically engineering model plants and microorganisms to find the optimum cell wall structure for the ultimate second generation bioethanol crop. Charis Cook and Alessandra Devoto highlight here the progress made to tailor the plant cell wall to improve the accessibility of cellulose by acting on the regulation, the structure or the relative composition of other cell wall components to ultimately improve saccharification efficiency. They also consider possible side effects of cell wall modification and focus on the latest advances made to improve the efficiency of digestion of lignocellulosic materials by cell wall degrading microorganisms.

Hemicelluloses negatively affect lignocellulose crystallinity for high biomass digestibility under NaOH and H2SO4 pretreatments in Miscanthus

“…In the current work, total hemicelluloses level was demonstrated to be the positive and dominant factor that affected the high biomass saccharification efficiency due to its negative effect on lignocellulose crystallinity (CrI). Hemicelluloses are proposed to deposit into cell walls via crosslink to cellulose by hydrogen bonds [14,29]. Thus, hemicelluloses can reduce cellulose crystallization and the negative effect of the hemicelluloses level may not depend on the cellulose as well as lignin levels (Table 1).…”

Second generation bioethanol (SGB) production potential in Turkey

“…Lignin is waterproof and provides an effective barrier to water‐soluble enzymes. Limiting lignin deposition could increase the ability of cellulolytic enzymes to access and hydrolyze its substrate .…”

Successful Application of an Ionic Liquid Carrying the Fluoride Counter‐ion in Biomacromolecular Chemistry: Microwave‐Assisted Acylation of Cellulose in the Presence of 1‐Allyl‐3‐methylimidazolium Fluoride/DMSO Mixtures

“…Cellulose is the most abundant biopolymer; it is the source of many important derivatives, including esters and ethers that are employed in diverse applications (fibers, films, membranes, etc.). Cellulose‐containing biomass is being intensely investigated as raw material for the production of bioethanol,1, 2 and other important chemicals 3…”